William J. Maloney, MD

All Publications

• The Influence of an Unexpected Symbolic Gift on Postoperative Arthroplasty Patients' Press Ganey Scores. The Journal of arthroplasty Lee, J. J., Mitchell, A. R., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2024

  Abstract

  INTRODUCTION: Hospitals use Press Ganey surveys to evaluate patient satisfaction. The goal of our study was to evaluate whether surgeon-driven gifting to patients post-operatively affects Press Ganey Survey responses.METHODS: There were 1,468 patients undergoing arthroplasty at our institution who were randomized to receive a thank you gift, a small bouquet of flowers, and a note from their provider after surgery, or nothing for completing their pre-operative arthroplasty registry questionnaire. Press Ganey surveys were sent to patients who received and did not receive flowers immediately after their hospital stay and after the patients' first post-operative visit. Scores were reported as the mean score and the fraction of responses with a top-box rating. One-sided student t-tests and Fischer Exact tests were used to assess statistical significance.RESULTS: Hospital Discharge Patients who received flowers had higher Press Ganey survey scores than patients who did not receive flowers. For example, for "Physician's concerns for questions," they had higher scores (mean difference: 3.7 ± 1.6 points, P = 0.012) and a 9% higher top-box rating (P = 0.032). For "Staff attitude towards visitors," they also had higher scores (mean difference: 2.8 ± 1.3 points, P = 0.019) and a 7% higher top-box rating (P = 0.049). First Follow-up Patients who received flowers had a higher top-box rating for "Concern provider showed for questions" and "Amount of time provider spent with you" by 6% (P = 0.046) and 11% (P = 0.009), respectively. They also had higher scores for "Information provider gave about medications" (mean difference: 4.0 ± 1.6 points, P = 0.009) and 11% higher top-box rating (P = 0.006).DISCUSSION: Press Ganey Surveys were higher in orthopaedic patients who received bouquets of flowers from their arthroplasty surgeons compared to patients who did not. At follow-up, improved Press Ganey scores persisted if the patient received flowers. The gift of flowers generates patient loyalty to their surgeon.

  View details for DOI 10.1016/j.arth.2024.07.018

  View details for PubMedID 39025277

• The outcome of revision total hip arthroplasty for instability. The bone & joint journal Apinyankul, R., Hong, C., Hwang, K. L., Burket Koltsov, J. C., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2024; 106-B (5 Supple B): 105-111

  Abstract

  Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocation. The aim of this study was to assess the risk for recurrent dislocation after revision THA for instability.Between 2009 and 2019, 163 patients underwent revision THA for instability at Stanford University Medical Center. Of these, 33 (20.2%) required re-revision due to recurrent dislocation. Cox proportional hazard models, with death and re-revision surgery for periprosthetic infection as competing events, were used to analyze the risk factors, including the size and alignment of the components. Paired t-tests or Wilcoxon signed-rank tests were used to assess the outcome using the Veterans RAND 12 (VR-12) physical and VR-12 mental scores, the Harris Hip Score (HHS) pain and function, and the Hip disability and Osteoarthritis Outcome score for Joint Replacement (HOOS, JR).The median follow-up was 3.1 years (interquartile range 2.0 to 5.1). The one-year cumulative incidence of recurrent dislocation after revision was 8.7%, which increased to 18.8% at five years and 31.9% at ten years postoperatively. In multivariable analysis, a high American Society of Anesthesiologists (ASA) grade (hazard ratio (HR) 2.72 (95% confidence interval (CI) 1.13 to 6.60)), BMI between 25 and 30 kg/m2 (HR 4.31 (95% CI 1.52 to 12.27)), the use of specialized liners (HR 5.39 (95% CI 1.97 to 14.79) to 10.55 (95% CI 2.27 to 49.15)), lumbopelvic stiffness (HR 6.03 (95% CI 1.80 to 20.23)), and postoperative abductor weakness (HR 7.48 (95% CI 2.34 to 23.91)) were significant risk factors for recurrent dislocation. Increasing the size of the acetabular component by > 1 mm significantly decreased the risk of dislocation (HR 0.89 (95% CI 0.82 to 0.96)). The VR-12 physical and HHS (pain and function) scores improved significantly at mid term.Patients requiring revision THA for instability are at risk of recurrent dislocation. Higher ASA grades, being overweight, a previous lumbopelvic fusion, the use of specialized liners, and postoperative abductor weakness are significant risk factors.

  View details for DOI 10.1302/0301-620X.106B5.BJJ-2023-0726.R1

  View details for PubMedID 38688516

• Strengthening the Pipeline: Promoting Diversity into Orthopedic Surgery. Clinics in sports medicine van Niekerk, M., O'Mara, A., Kha, S., Zhou, J., McAdams, T. A., Ladd, A., Shea, K., Frick, S., Maloney, W. J., Chu, C. R. 2024; 43 (2): 253-270

  Abstract

  The United States is a nation of diverse racial and ethnic origins. Athletes represent the full spectrum of the nation's population. However, the orthopedic surgeons who serve as team physicians are Caucasian and male with staggeringly few exceptions. This manuscript provides an overview of the current status and barriers to diversity among orthopedic team physicians, along with strategies to address the issue. Specifically, pipeline initiatives implemented at one academic medical school and orthopedic surgery department are summarized as potential models that can be further developed by other institutions to enhance diversity in orthopedic surgery.

  View details for DOI 10.1016/j.csm.2023.07.007

  View details for PubMedID 38383108

• AOA Critical Issues: How Research Improves Clinical Care: The Case for Orthopaedic Surgeon Research Leadership and Collaboration: AOA Critical Issues Symposium. The Journal of bone and joint surgery. American volume Chu, C. R., Murray, M. M., Maloney, W. J., Hogan, M. V. 2023

  Abstract

  Improving the performance and impact of orthopaedic research is a critical leadership challenge. Musculoskeletal (MSK) conditions are a leading cause of disability worldwide, for which research investment and performance lags far behind the burden of disease. In the United States, MSK disorders account for the highest health care costs, have increased in incidence at the fastest rate, and exceed the combined costs of cardiovascular diseases and neoplasms. Despite the cost to society, the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), with primary responsibility for MSK research, receives <1.4% of the funds allocated to the National Institutes of Health (NIH). Although orthopaedic surgeons are leading providers of MSK clinical care, the dearth of orthopaedic clinician-scientists also greatly reduces representation of MSK scientific and clinical expertise among academic and scientific leaders. The goals of this symposium were to highlight the critical need for greater prioritization and investment in orthopaedic research and to engage orthopaedic leaders in addressing these needs. Compelling stories of research success from 3 orthopaedic chairs were featured to highlight how orthopaedic surgeon leadership in bench-to-bedside research substantially advances MSK clinical care. Seminar participants also emphasized the need to improve evidence-based clinical practice for which multicenter prospective cohort and registry studies represent opportunities for broader involvement. Prioritization of orthopaedic clinician-scientist development and formation of multidisciplinary partnerships with basic and translational scientists were emphasized as critical needs to advance MSK health. It is critical for orthopaedic chairs to "be invested in" and to "invest in" the success of orthopaedic research. This investment includes developing a professional climate that values research achievement and collaboration as well as implementing strategies to support and sustain research success. Finally, orthopaedic leaders need to advocate for federal research funding to be proportional to the economic burden of disease for which MSK conditions carry the highest current and projected costs. With health-care costs accounting for nearly one-fifth of the U.S. economy, increasing the investment in orthopaedic research to reduce the prevalence, disability, and morbidity from MSK disease needs to be a top orthopaedic and national leadership priority.

  View details for DOI 10.2106/JBJS.23.00599

  View details for PubMedID 38117871

• Host and Microbial Characteristics Associated with Recurrent Prosthetic Joint Infections. Journal of orthopaedic research : official publication of the Orthopaedic Research Society Hampton, J. P., Zhou, J. Y., Kameni, F. N., Espiritu, J. R., Manasherob, R., Cheung, E., Miller, M. D., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2023

  Abstract

  Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009-2020. Infection was defined according to the 2018 Musculoskeletal Infection Society criteria. Thirty-nine cases ("recurrent-PJI") received at least two antibiotic spacers before clinical resolution of their infection, and 67 controls ("single-PJI") received a single antibiotic cement spacer prior to infection-free prosthesis reimplantation. Patient demographics, McPherson host grade, and culture results including antibiotic susceptibilities were compared. Fifty-two (78%) single-PJI and 32 (82%) recurrent-PJI patients had positive intraoperative cultures at the time of their initial spacer procedure. The odds of polymicrobial infections were 11-fold higher among recurrent-PJI patients, and the odds of significant systemic compromise (McPherson host-grade C) were more than double. Recurrent-PJI patients were significantly more likely to harbor Staphylococcus aureus. We found no differences between cases and controls in pathogen resistance to the six most tested antibiotics. Among recurrent-PJI patients, erythromycin-resistant infections were more prevalent at the final than initial spacer, despite no erythromycin exposure. Our findings suggest that McPherson host grade, polymicrobial infection, and S. aureus infection are key indicators of secondary or persistent joint infection following resection arthroplasty and antibiotic spacer placement, while bacterial resistance does not predict infection-related arthroplasty failure. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/jor.25768

  View details for PubMedID 38093490

• Excellent 20-Year Results of Total Hip Arthroplasty with Highly Cross-Linked Polyethylene on Cobalt-Chromium Femoral Heads in Patients ≤50 Years. The Journal of arthroplasty Parilla, F. W., Youngman, T. R., Layon, D., Ince, D. C., Pashos, G. E., Maloney, W. J., Clohisy, J. C. 2023

  Abstract

  Highly cross-linked polyethylene (HXPLE) acetabular bearing surfaces have appeared to offer excellent wear resistance, low incidence of wear-related osteolysis, and high implant survivorship at 10- to 15-year follow-ups. However, concerns over potential performance deterioration at longer-term follow-up remain - particularly in younger patients - and outcome data into the third decade have not been available.We retrospectively assessed 62 patients (68 hips) who underwent primary total hip arthroplasty (THA) at age ≤50 years with a single manufacturer's cementless components, remelted HXLPE liner, and small diameter (26 and 28 millimeter) cobalt-chromium (CoCr) femoral heads at minimum 18-year follow-up. We assessed clinical outcomes (modified Harris Hip score, UCLA (University of California Los Angeles Activity Score), polyethylene wear rates, radiographic findings (osteolysis, component loosening), and implant survivorship.At 20.6-year mean follow-up (range, 18 to 23 years) modified Harris Hip scores for surviving hips remained an average of 41 points above preoperative baseline (49 vs. 90, P<0.001) and UCLA scores 2.8 points above baseline (3.7 vs. 6.4, P<0.001). Wear analysis revealed a population linear wear rate of 0.0142 mm/year (Standard deviation (SD), 0.0471) and volumetric wear rate of 10.14 mm3/year (SD, 23.41). Acetabular lysis was noted in two asymptomatic hips at 16.6 and 18.4 years. No components were radiographically loose. Survivorship free from wear-related revision was 100% at 20 years (97% [95% Confidence Interval (CI), 86.9-99.1%] free from any revision).At 20-year follow-up, HXLPE bearings in this young cohort retained excellent wear characteristics. The HXLPE-CoCr bearing couple with small femoral heads continues to be extremely effective 20 years after primary THA in the younger patient population.

  View details for DOI 10.1016/j.arth.2023.08.025

  View details for PubMedID 37572728

• An osteoinductive and biodegradable intramedullary implant accelerates bone healing and mitigates complications of bone transport in male rats. Nature communications Lin, S., Maekawa, H., Moeinzadeh, S., Lui, E., Alizadeh, H. V., Li, J., Kim, S., Poland, M., Gadomski, B. C., Easley, J. T., Young, J., Gardner, M., Mohler, D., Maloney, W. J., Yang, Y. P. 2023; 14 (1): 4455

  Abstract

  Bone transport is a surgery-driven procedure for the treatment of large bone defects. However, challenging complications include prolonged consolidation, docking site nonunion and pin tract infection. Here, we develop an osteoinductive and biodegradable intramedullary implant by a hybrid tissue engineering construct technique to enable sustained delivery of bone morphogenetic protein-2 as an adjunctive therapy. In a male rat bone transport model, the eluting bone morphogenetic protein-2 from the implants accelerates bone formation and remodeling, leading to early bony fusion as shown by imaging, mechanical testing, histological analysis, and microarray assays. Moreover, no pin tract infection but tight osseointegration are observed. In contrast, conventional treatments show higher proportion of docking site nonunion and pin tract infection. The findings of this study demonstrate that the novel intramedullary implant holds great promise for advancing bone transport techniques by promoting bone regeneration and reducing complications in the treatment of bone defects.

  View details for DOI 10.1038/s41467-023-40149-5

  View details for PubMedID 37488113

  View details for PubMedCentralID 5935655

• Arthroplasty for femoral neck fractures is at risk for under restoration of lateral femoral offset. Hip international : the journal of clinical and experimental research on hip pathology and therapy Shah, H. N., Barrett, A. A., Finlay, A. K., Arora, P., Bellino, M. J., Bishop, J. A., Gardner, M. J., Miller, M. D., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2023: 11207000231169914

  Abstract

  PURPOSE: The aim of the study was to determine the restoration of hip biomechanics through lateral offset, leg length, and acetabular component position when comparing non-arthroplasty surgeons (NAS) to elective arthroplasty surgeons (EAS).METHODS: 131 patients, with a femoral neck fracture treated with a THA by 7 EAS and 20 NAS, were retrospectively reviewed. 2 blinded observers measured leg-length discrepancy, femoral offset, and acetabular component position. Multivariate logistic regression models examined the association between the surgeon groups and restoration of lateral femoral, acetabular offset, leg length discrepancy, acetabular anteversion, acetabular position, and component size, while adjusting for surgical approach and spinal pathology.RESULTS: NAS under-restored 4.8mm of lateral femoral offset (43.9±8.7mm) after THA when compared to the uninjured side (48.7±7.1mm, p=0.044). NAS were at risk for under-restoring lateral femoral offset when compared to EAS (p=0.040). There was no association between lateral acetabular offset, leg length, acetabular position, or component size and surgeon type.CONCLUSIONS: Lateral femoral offset is at risk for under-restoration after THA for femoral neck fractures, when performed by surgeons that do not regularly perform elective THA. This indicates that lateral femoral offset is an under-appreciated contributor to hip instability when performing THA for a femoral neck fracture. Lateral femoral offset deserves as much attention and awareness as acetabular component position since a secondary analysis of our data reveal that preoperative templating and intraoperative imaging did not prevent under-restoration.

  View details for DOI 10.1177/11207000231169914

  View details for PubMedID 37128124

• Assessment of Team Dynamics and Operative Efficiency in Hip and Knee Arthroplasty. JAMA surgery Cousins, H. C., Cahan, E. M., Steere, J. T., Maloney, W. J., Goodman, S. B., Miller, M. D., Huddleston, J. I., Amanatullah, D. F. 2023

  Abstract

  Surgical team communication is a critical component of operative efficiency. The factors underlying optimal communication, including team turnover, role composition, and mutual familiarity, remain underinvestigated in the operating room.To assess staff turnover, trainee involvement, and surgeon staff preferences in terms of intraoperative efficiency.Retrospective analysis of staff characteristics and operating times for all total joint arthroplasties was performed at a tertiary academic medical center by 5 surgeons from January 1 to December 31, 2018. Data were analyzed from May 1, 2021, to February 18, 2022. The study included cases with primary total hip arthroplasties (THAs) and primary total knee arthroplasties (TKAs) comprising all primary total joint arthroplasties performed over the 1-year study interval.Intraoperative turnover among nonsurgical staff, presence of trainees, and presence of surgeon-preferred staff.Incision time, procedure time, and room time for each surgery. Multivariable regression analyses between operative duration, presence of surgeon-preferred staff, and turnover among nonsurgical personnel were conducted.A total of 641 cases, including 279 THAs (51% female; median age, 64 [IQR, 56.3-71.5] years) and 362 TKAs (66% [238] female; median age, 68 [IQR, 61.1-74.1] years) were considered. Turnover among circulating nurses was associated with a significant increase in operative duration in both THAs and TKAs, with estimated differences of 19.6 minutes (SE, 3.5; P < .001) of room time in THAs and 14.0 minutes (SE, 3.1; P < .001) of room time in TKAs. The presence of a preferred anesthesiologist or surgical technician was associated with significant decreases of 26.5 minutes (SE, 8.8; P = .003) of procedure time and 12.6 minutes (SE, 4.0; P = .002) of room time, respectively, in TKAs. The presence of a surgeon-preferred vendor was associated with a significant increase in operative duration in both THAs (26.3 minutes; SE, 7.3; P < .001) and TKAs (29.6 minutes; SE, 9.6; P = .002).This study found that turnover among operative staff is associated with procedural inefficiency. In contrast, the presence of surgeon-preferred staff may facilitate intraoperative efficiency. Administrative or technologic support of perioperative communication and team continuity may help improve operative efficiency.

  View details for DOI 10.1001/jamasurg.2023.0168

  View details for PubMedID 36947044

  View details for PubMedCentralID PMC10034665

• Complications, Implant Survivorships, and Functional Outcomes of Conversion Total Knee Arthroplasty with Prior Hardware. The Journal of arthroplasty Apinyankul, R., Hui, A. Y., Hwang, K., Segovia, N. A., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2023

  Abstract

  End-stage knee osteoarthritis with retained peri-articular hardware is a frequent scenario. Conversion total knee arthroplasty (TKA) leads to excellent outcomes, but poses unique challenges. The evidence supporting retention vs. removal of hardware during TKA is controversial.Patients who underwent TKA with prior hardware between January 2009 and December 2019 were identified. A total of 148 patients underwent TKA with prior hardware. Mean follow-up was 60 months (range, 24 to 223). Univariate and multivariable analyses were used to study correlations among factors and surgical-related complications, prosthesis failures, and functional outcomes.The complication rate was 28 of 148 (18.9%). The use of a quadriceps snips in addition to a medial parapatellar arthrotomy was associated with a higher complication (Odds ratio (OR) 20.7, p < 0.05), implant failures (OR 13.9, p < 0.05), and lower Veteran Rand 12 Mental Score (VR-12 MS) (-14.8, p < 0.05). Hardware removal vs. retention and use of single vs. multiple incisions were not associated with complications or prosthesis failures. Removal of all hardware was associated with significantly higher (+7.3, p < 0.05) VR-12 MS compared to retention of all hardware.TKA with prior hardware was associated with more complications, implant failures, and lower VR-12 MS when a more constrained construct or quadriceps snip was performed. This probably reflects the level of difficulty of the procedure, rather than the surgical approach used. Hardware removal or retention was not associated with complications or implant failures; however, removal rather than retention of all prior hardware is associated with increased general health outcomes.

  View details for DOI 10.1016/j.arth.2023.01.049

  View details for PubMedID 36758842

• A bioactive compliant vascular graft modulates macrophage polarization and maintains patency with robust vascular remodeling. Bioactive materials Stahl, A., Hao, D., Barrera, J., Henn, D., Lin, S., Moeinzadeh, S., Kim, S., Maloney, W., Gurtner, G., Wang, A., Yang, Y. P. 2023; 19: 167-178

  Abstract

  Conventional synthetic vascular grafts are associated with significant failure rates due to their mismatched mechanical properties with the native vessel and poor regenerative potential. Though different tissue engineering approaches have been used to improve the biocompatibility of synthetic vascular grafts, it is still crucial to develop a new generation of synthetic grafts that can match the dynamics of native vessel and direct the host response to achieve robust vascular regeneration. The size of pores within implanted biomaterials has shown significant effects on macrophage polarization, which has been further confirmed as necessary for efficient vascular formation and remodeling. Here, we developed biodegradable, autoclavable synthetic vascular grafts from a new polyurethane elastomer and tailored the grafts' interconnected pore sizes to promote macrophage populations with a pro-regenerative phenotype and improve vascular regeneration and patency rate. The synthetic vascular grafts showed similar mechanical properties to native blood vessels, encouraged macrophage populations with varying M2 to M1 phenotypic expression, and maintained patency and vascular regeneration in a one-month rat carotid interposition model and in a four-month rat aortic interposition model. This innovative bioactive synthetic vascular graft holds promise to treat clinical vascular diseases.

  View details for DOI 10.1016/j.bioactmat.2022.04.004

  View details for PubMedID 35510174

• Revision hip arthroplasty using a modular, cementless femoral stem: long-term follow-up. The Journal of arthroplasty Valtanen, R. S., Hwang, K. L., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2022

  Abstract

  BACKGROUND: As the number of primary total hip arthroplasty (THA) cases increase, so does the demand for revision operations. However, long-term follow-up data for revision THA is lacking.METHODS: A retrospective review was completed of patients who underwent revision THA at a single institution between January 2002 and October 2007 using a cementless modular stem. Patient demographic, clinical, and radiographic data was collected. Preoperative and postoperative patient reported outcome (PRO) scores were compared at a minimum of fourteen-year follow-up.RESULTS: Eighty-four patients (89 hips) with a median age of 69 years (range, 28 to 88) at operation were included. Indications for revision included aseptic loosening (84.2%), infection (12.4%), and periprosthetic fracture (3.4%). Twenty-two hips sustained at least one complication: intraoperative fracture (7.9%), dislocation (6.7%), prosthetic joint infection (4.5%), deep venous thrombosis (3.4%), late periprosthetic fracture (2.2%). There were no modular junction complications. Eight patients underwent reoperations; only three involved the stem. Thirty-eight patients (45%) were deceased prior to final follow-up without known reoperations. Twenty-seven patients (32%) were lost to follow-up. Twenty-one patients (23%) were alive at minimum fourteen-year follow-up. Complete PROs were available for nineteen patients (range, 14 to 18.5 years follow-up). Significant improvement was seen in UCLA Activity, VR-12 physical, HOOS, JR., and HHS pain and function scores.CONCLUSION: Challenges of long-term follow-up include patient migration, an unwillingness to travel for re-examination, medical comorbidities, advanced age, and death. The cementless modular revision stem demonstrated long-term clinical success and remains a safe and reliable option for complex revision operations.

  View details for DOI 10.1016/j.arth.2022.12.018

  View details for PubMedID 36535440

• Outcome of the Wagner Cone femoral component for difficult anatomical conditions during total hip arthroplasty. International orthopaedics Lawson, K., Hwang, K. L., Montgomery, S., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2022

  Abstract

  PURPOSE: Total hip arthroplasty (THA) in patients with small or unusual proximal femoral anatomy is challenging due to sizing issues, control of version, and implant fixation. The Wagner Cone is a monoblock, fluted, tapered stem with successful outcomes for these patients; however, there is limited information on subsidence, a common finding with cementless stems.METHODS: We retrospectively reviewed our cases using the modified Wagner Cone (Zimmer, Warsaw, IN) implanted over a 13-year period (2006-2019) in patients with small or abnormal proximal femoral anatomy. We performed 144 primary THAs in 114 patients using this prosthesis. Mean follow-up was 4.5±3.4years (range, 1-13years). Common reasons for implantation were hip dysplasia (52%) and osteoarthritis in patients with small femoral proportions (22%). Analysis of outcomes included assessment of stem subsidence and stability.RESULTS: Survival was 98.6% in aseptic cases; revision-free survival was 97.9%. Femoral subsidence occurred in 84 cases (58%). No subsidence progressed after 3months. Of those that subsided, the mean distance was 2.8±2.0mm. There was less subsidence in stems that stabilized prior to sixweeks (2.2±1.4mm) compared to those that continued until 12weeks (3.9±1.6, p=0.02). Harris Hip, UCLA, and WOMAC scores significantly improved from pre-operative evaluation (p<0.001*, p<0.003*, p≪0.001*); there was no difference in outcome between patients with and without subsidence (p=0.430, p=0.228, p=0.147).CONCLUSION: The modified Wagner Cone demonstrates excellent clinical outcomes in patients with challenging proximal femoral anatomy. Subsidence is minor, stops by 3months, and does not compromise clinical outcome.

  View details for DOI 10.1007/s00264-022-05608-6

  View details for PubMedID 36224431

• Isolated Versus Full Component Revision In Total Knee Arthroplasty For Aseptic Loosening. The Journal of arthroplasty Apinyankul, R., Hwang, K., Segovia, N. A., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2022

  Abstract

  Revision of both femoral and tibial components of a total knee arthroplasty (TKA) for aseptic loosening has favorable outcomes. Revision of only one loose component with retention of others has shorter operative time and lower cost, however, implant survivorship and clinical outcomes of these different operations are unclear.Between January 2009 and December 2019, a consecutive cohort of revision TKA were reviewed. Univariate and multivariable analyses were used to study correlations among factors and surgical related complications, time to prosthesis failure, and functional outcomes (University of California Los Angeles (UCLA), Knee Society (KS) functional, Knee osteoarthritis and outcome score for joint replacement (KOOS JR), Veterans RAND 12 (VR-12) physical, and VR-12 mental).A total of 238 patients underwent revision TKA for aseptic loosening. The mean follow-up time was 61 months (range 25 to 152). Ten of the 105 patients (9.5%) who underwent full revision (both femoral and tibial components) and 18 of the 133 (13.5%) who underwent isolated revision had subsequent prosthesis failure [Hazard ratio (HR) 0.67, p = 0.343]. The factor analysis of type of revision (full or isolated revision) did not demonstrate a significant difference between groups in terms of complications, implant failures, and times to failure. Metallosis was related to early time to failure [HR 10.11, p < 0.001] and iliotibial band release was associated with more complications (Odds ratio (OR) 9.87, p = 0.027). Preoperative symptoms of instability were associated with the worst improvement in UCLA score. Higher American Society of Anesthesiologists (ASA) and higher Charlson Comorbidity Index (CCI) were related with worse VR-12 physical (-30.5, p = 0.008) and KOOS JR (-4.2, p = 0.050) scores, respectively.Isolated and full component revision TKA for aseptic loosening do not differ with respect to prosthesis failures, complications, and clinical results at 5 years. Poor ASA status, increased comorbidities, instability, and a severe bone defect are related to worse functional improvement.

  View details for DOI 10.1016/j.arth.2022.09.006

  View details for PubMedID 36099937

• The Impact of Extended Trochanteric Osteotomy with Cerclage Fixation in Revision Total Hip Arthroplasty for Prosthetic Joint Infection. The Journal of arthroplasty Whittaker, M. J., Arora, P., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2022

  Abstract

  BACKGROUND: An extended trochanteric osteotomy (ETO) is a powerful tool for femoral component revision. There is limited evidence that directly supports its use in the setting of a prosthetic joint infection (PJI). Cerclage fixation raises the theoretical concern for persistent infection.METHODS: The institutional database included 76 ETOs for revision arthroplasty between January 1, 2008 and December 31, 2019. The cohort was divided based on indication for femoral component revision: PJI versus aseptic revision. The PJI group was subdivided based on second stage exchange versus retention of initial cerclage fixation. Operative time, estimated blood loss, complications, and rate of repeat revision surgery were evaluated.RESULTS: Forty-nine patients (64%) underwent revision for PJI and 27 patients (36%) underwent aseptic revision. There was no significant difference in operative times (p = 0.082), postoperative complications (p = 0.258), or rate of repeat revision surgery (p = 0.322) between groups. Of the 49 patients in the PJI group, 40 (82%) retained cerclage fixation while 9 (18%) had cerclage exchange. Cerclage exchange did not significantly impact operative time (p = 0.758), blood loss (p = 0.498), rate of repeat revision surgery (p = 0.302), or postoperative complications (p = 0.253) including infection (p = 0.639).CONCLUSION: An ETO remains a powerful tool for femoral component removal, even in the presence of a PJI. A multi-institutional investigation would be required to validate observed trends toward better infection control with cerclage exchange. Cerclage exchange did not appear to increase operative time, blood loss, or postoperative complication rates.

  View details for DOI 10.1016/j.arth.2022.08.041

  View details for PubMedID 36067886

• Costs and benefits of routine hemoglobin A1c screening prior to total joint arthroplasty: a cost-benefit analysis CURRENT ORTHOPAEDIC PRACTICE Zhuang, T., Shapiro, L. M., Amanatullah, D. F., Maloney, W. J., Kamal, R. N. 2022; 33 (4): 338-346

  View details for Web of Science ID 000816578100006

• Effect of Perioperative Gabapentin on Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: A Randomized Clinical Trial (vol 153, pg 303, 2018) JAMA SURGERY Hah, J., Mackey, S. C., Schmidt, P. 2022; 157 (6): 553

  View details for DOI 10.1001/jamasurg.2022.1392

  View details for Web of Science ID 000809213600033

• Costs and benefits of routine hemoglobin A1c screening prior to total joint arthroplasty: a cost-benefit analysis. Current orthopaedic practice Zhuang, T., Shapiro, L. M., Amanatullah, D. F., Maloney, W. J., Kamal, R. N. 2022; 33 (4): 338-346

  Abstract

  Poorly controlled diabetes mellitus (DM) increases the risk for periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). While institutional protocols include hemoglobin A1c (HbA1c) screening in TJA patients, the costs and benefits of routine preoperative screening have not been described.The authors created a decision tree model to evaluate short-term costs and risk reduction for PJIs with routine screening of primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. Probabilities and costs were obtained from published sources. They calculated net costs and absolute risk reduction in PJI for routine screening versus no screening. The authors also performed sensitivity analyses of model inputs including probabilistic sensitivity analyses (PSAs) consisting of 10,000 Monte Carlo simulations.In patients with DM, routine screening before THA resulted in net cost savings of $81 per patient with 286 patients needing to be screened to prevent 1 PJI, while screening before TKA incurred net additional costs of $25,810 per PJI prevented. Routine screening in patients with DM undergoing THA or TKA was cost-saving across 75.5% or 21.8% of PSA simulations, respectively. In patients with no history of DM, routine screening before THA or TKA incurred net additional costs of $24,583 or $87,873 per PJI prevented, respectively.Routine HbA1c screening in patients with DM prior to THA with referral of patients with elevated HbA1c for glycemic optimization may prevent PJI and reduce healthcare costs. In contrast, routine screening in patients with DM prior to TKA or in patients with no history of DM is not cost-saving.Economic Level IV.

  View details for DOI 10.1097/bco.0000000000001131

  View details for PubMedID 36340586

  View details for PubMedCentralID PMC9632610

• Effect of Perioperative Gabapentin on Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: A Randomized Clinical Trial (vol 153, pg 303, 2018) JAMA SURGERY Hah, J., Mackey, S. C., Schmidt, P. 2022

  View details for DOI 10.1001/jamasurg.2017.4915

  View details for Web of Science ID 000784959200002

• Long-term Follow-up of Conventional Polyethylene in Total Hip Arthroplasty in Young Patients: Heightened Wear-related Complications are Observed at the Beginning of the Third Decade. The Journal of arthroplasty Parilla, F. W., Ince, D. C., Pashos, G. E., Maloney, W. J., Clohisy, J. C. 2022

  Abstract

  Conventional polyethylene (CPE) was used widely in the past as a bearing surface in total hip arthroplasty (THA). As CPE THAs age and the revision burden continues to grow, it is increasingly important to understand the durability and failure mechanisms of this bearing material. Currently, such long-term data remain limited, particularly in younger, more active patients in whom wear issues are of greater concern.We retrospectively reviewed 90 hips (77 patients) that underwent primary THA with CPE bearings on CoCr femoral heads at age ≤50 years at 20-year minimum follow-up (mean 21.6 [20-23]). We analyzed polyethylene wear rates, clinical outcomes (modified Harris Hip score, UCLA Activity score), and implant survivorship.Wear analysis revealed a median linear wear rate of 0.113mm/year (95% CI [0.102-0.148) and a median volumetric wear rate of 41.20 mm3/year (95% CI [43.5-61.0]). Modified Harris Hip scores remained 37 points above preoperative baseline (p<0.001) and UCLA scores 1.4 points above baseline (p=0.018) at 21.6-year mean follow-up. Twenty-nine hips (32.2%) were revised, 20 of which (22.2%) were wear-related at a median of 15.4 years (IQR, 11.4-19.5). Survivorship free from wear-related revision was 95.6% (95% CI [88.7-98.3]), 87.9% [78.6-93.3], 78.1% [49.6-66.5], and 61.1% [41.3-67.0] at 10, 15, 20, and 25 years.Wear-related issues developed at increasingly high rates after 15 years, suggesting the need for surveillance after this time. The long-term wear and survivorship data of this study may be used as a benchmark when evaluating the performance of contemporary bearings in young, active THA patients.

  View details for DOI 10.1016/j.arth.2022.04.011

  View details for PubMedID 35460812

• Staging Bilateral Total Knee Arthroplasties Reduces Alignment Outliers. The Journal of arthroplasty Follett, M. A., Arora, P., Maloney, W. J., Goodman, S. B., Huddleston, J. I., Amanatullah, D. F. 1800

  Abstract

  PURPOSE: Patients frequently present with bilateral symptomatic knee osteoarthritis and request simultaneous total knee arthroplasties (TKAs). Technical differences between simultaneous and staged TKAs could affect clinical and radiographic outcomes. We hypothesized staged TKAs would have fewer mechanical alignment outliers than simultaneous TKAs.METHODS: We reviewed 87 simultaneous and 72 staged TKAs with at least 2 years of follow-up. Radiographic assessment was done using standing long leg and lateral radiographs of the knee. Coronal and sagittal measurements were performed by four blinded observers on two separate occasions with an intra-observer agreement of 0.95 and inter-observer of 0.92.RESULTS: The first simultaneous knee had no difference in the probability of establishing the mechanical axis outside 3° of neutral (45%) compared to the first staged knee (54%, p = 0.337). However, the second simultaneous knee (49%) was more likely to establish the axis outside mechanical neutral compared to the second staged knee (28%; Odds Ratio (OR): 2.54, Confidence Interval (CI): 1.31 - 4.94, p = 0.006). There was an increased risk of deep venous thrombosis with staged TKA (OR: 2.96, CI: 1.28 - 6.84, p = 0.011), but other perioperative complication rates were not significantly different. There were no clinically significant differences in range of motion or Knee Society Score.CONCLUSION: There is a significantly increased risk of establishing the second knee outside mechanical neutral during a simultaneous TKA compared to staged bilateral TKAs, possibly related to a number of surgeon- and system-related factors. The impact on clinical outcomes and radiographic loosening may become significant in long-term follow up.

  View details for DOI 10.1016/j.arth.2022.01.003

  View details for PubMedID 35017050

• Tendency of Driving to the Basket Is Associated With Increased Risk of Anterior Cruciate Ligament Tears in National Basketball Association Players: A Cohort Study ORTHOPAEDIC JOURNAL OF SPORTS MEDICINE Schultz, B. J., Thomas, K. A., Cinque, M., Harris, J. D., Maloney, W. J., Abrams, G. D. 2021; 9 (11)

  View details for DOI 10.1177/23259671211052953

  View details for Web of Science ID 000715843600001

• Tendency of Driving to the Basket Is Associated With Increased Risk of Anterior Cruciate Ligament Tears in National Basketball Association Players: A Cohort Study. Orthopaedic journal of sports medicine Schultz, B. J., Thomas, K. A., Cinque, M., Harris, J. D., Maloney, W. J., Abrams, G. D. 2021; 9 (11): 23259671211052953

  Abstract

  Driving to the basket in basketball involves acceleration, deceleration, and lateral movements, which may expose players to increased anterior cruciate ligament (ACL) injury risk. It is unknown whether players who heavily rely on driving have decreased performance on returning to play after ACL reconstruction (ACLR).Players with a greater tendency to drive to the basket would be more likely to tear their ACL versus noninjured controls and would experience decreased performance when returning to play after ACLR.Case-control study; Level of evidence, 3.Season-level performance statistics and ACL injuries were aggregated for National Basketball Association (NBA) seasons between 1980 and 2017 from publicly available sources. Players' tendency to drive was calculated using 49 common season-level performance metrics. Each ACL-injured player was matched with 2 noninjured control players by age, league experience, and style of play metrics. Points, playing minutes, driving, and 3-point shooting tendencies were compared between players with ACL injuries and matched controls. Independent-samples t test was utilized for comparisons.Of 86 players with a total of 96 ACL tears identified in the NBA, 50 players were included in the final analysis. Players who experienced an ACL tear had a higher career-average drive tendency than controls (P = .047). Players with career-average drive tendency ≥1 standard deviation above the mean were more likely to tear their ACL than players with drive tendency <1 standard deviation (5.2% vs 2.7%; P = .026). There was no significant difference in total postinjury career points (P = .164) or career minutes (P = .237) between cases and controls. There was also no significant change in drive tendency (P = .152) or 3-point shooting tendency (P = .508) after return to sport compared with controls.NBA players with increased drive tendency were more likely to tear their ACL. However, players who were able to return after ACLR did not underperform compared with controls and did not alter their style of play compared with the normal changes seen with age. This information can be used to target players with certain playing styles for ACL injury prevention programs.

  View details for DOI 10.1177/23259671211052953

  View details for PubMedID 34778484

  View details for PubMedCentralID PMC8573492

• An Open-Label Study to Evaluate the Effect of Intra-articular Triamcinolone Acetonide Extended Release on Patients with Baseline Synovitis and Osteoarthritis of the Knee Huffman, K., Kivitz, A., Conaghan, P., Bowes, M., Brett, A., Kraus, V., Maloney, W., Parvizi, J., Cinar, A., Bodick, N., Kelley, S. WILEY. 2021: 1480-1483

  View details for Web of Science ID 000744545202243

• Biologic Association Annual Summit: 2020 Report. Orthopaedic journal of sports medicine Frank, R. M., Sherman, S. L., Chahla, J., Dragoo, J. L., Mandelbaum, B., Members of the Biologic Association, Anz, A. W., Bradley, J. P., Chu, C. R., Cole, B. J., Farr, J., Flanigan, D. C., Gomoll, A. H., Halbrecht, J., Horsch, K., Lattermann, C., Leucht, P., Maloney, W. J., McIntyre, L. F., Murray, I., Muschler, G. F., Nakamura, N., Piuzzi, N. S., Rodeo, S. A., Saris, D. B., Shaffer, W. O., Shapiro, S. A., Spindler, K. P., Steinwachs, M., Tokish, J. M., Vangsness, C. T., Watson, J. T., Yanke, A. B., Zaslav, K. R. 2021; 9 (6): 23259671211015667

  Abstract

  Interest and research in biologic approaches for tissue healing are exponentially growing for a variety of musculoskeletal conditions. The recent hype concerning musculoskeletal biological therapies (including viscosupplementation, platelet-rich plasma, and cellular therapies, or "stem cells") is driven by several factors, including demand by patients promising regenerative evidence supported by substantial basic and translational work, as well as commercial endeavors that complicate the scientific and lay understanding of biological therapy outcomes. While significant improvements have been made in the field, further basic and preclinical research and well-designed randomized clinical trials are needed to better elucidate the optimal indications, processing techniques, delivery, and outcome assessment. Furthermore, biologic treatments may have potential devastating complications when proper methods or techniques are ignored. For these reasons, an association comprising several scientific societies, named the Biologic Association (BA), was created to foster coordinated efforts and speak with a unified voice, advocating for the responsible use of biologics in the musculoskeletal environment in clinical practice, spearheading the development of standards for treatment and outcomes assessment, and reporting on the safety and efficacy of biologic interventions. This article will introduce the BA and its purpose, provide a summary of the 2020 first annual Biologic Association Summit, and outline the future strategic plan for the BA.

  View details for DOI 10.1177/23259671211015667

  View details for PubMedID 34164559

• Perioperative Statin Use May Reduce Postoperative Arrhythmia Rates After Total Joint Arthroplasty. The Journal of arthroplasty Bonano, J. C., Aratani, A. K., Sambare, T. D., Goodman, S. B., Huddleston, J. I., Maloney, W. J., Burk, D. R., Aaronson, A. J., Finlay, A. K., Amanatullah, D. F. 2021

  Abstract

  BACKGROUND: Postoperative arrhythmias are associated with increased morbidity and mortality in total joint arthroplasty (TJA) patients. HMG-CoA (3-hydroxy-3-methyl-glutaryl-CoA) reductase inhibitors (statins) decrease atrial fibrillation rates after cardiac surgery, but it is unknown if this cardioprotective effect is maintained after joint reconstruction surgery. We aim to determine if perioperative statin use decreases the incidence of 90-day postoperative arrhythmias in patients undergoing primary TJA.METHODS: We performed a single-center retrospective cohort study in which 231 primary TJA patients (109 hips, 122 knees) received simvastatin 80 mg daily during their hospitalization as part of a single surgeon's standard postoperative protocol. This cohort was matched to 966 primary TJA patients (387 hips and 579 knees) that did not receive simvastatin. New-onset arrhythmias (bradycardia, atrial fibrillation/tachycardia/flutter, paroxysmal supraventricular tachycardia, and ventricular tachycardia) and complications (readmissions, thromboembolism, infection, and dislocation) within 90 days of the procedure were documented. Categorical variables were analyzed using Fisher's exact tests. Our study was powered to detect a 3% difference in arrhythmia rates.RESULTS: Within 90 days postoperatively, arrhythmias occurred in 1 patient (0.4%) who received a perioperative statin, 39 patients (4.0%) who did not receive statins (P= .003), and 24 patients (4.2%) who were on outpatient statins (P= .005). This is 10-fold reduction in the relative risk of developing a postoperative arrhythmia within 90 days of arthroplasty and an absolute risk reduction of 3.6%.CONCLUSION: Treating as few as 28 patients with perioperative simvastatin prevents one new cardiac arrhythmia within 90 days in statin-naive patients undergoing TJA.

  View details for DOI 10.1016/j.arth.2021.05.022

  View details for PubMedID 34127349

• Combining a vascular bundle and 3D printed scaffold with BMP-2 improves bone repair and angiogenesis. Tissue engineering. Part A Kawai, T., Pan, C., Okuzu, Y., Shimizu, T., Stahl, A., Matsuda, S., Maloney, W., Yang, Y. P. 2021

  Abstract

  Vascularization is currently considered the biggest challenge in bone tissue engineering due to necrosis in the center of large scaffolds. We established a new expendable vascular bundle model to vascularize a 3D printed channelled scaffold with and without BMP2 for improved healing of large segmental bone defects. Bone formation and angiogenesis in an 8 mm critical sized bone defect in the rat femur were significantly promoted by inserting a bundle consisting of the superficial epigastric artery and vein into the central channel of a large porous polycaprolactone scaffold. Vessels were observed sprouting from the vascular bundle inserted in the central tunnel. While the regenerated bone volume in the group receiving the scaffold and vascular bundle was similar to that of the healthy femur, the rate of union of the group was not satisfactory (25% at 8 weeks). BMP-2 delivery was found to promote not only bone formation, but also angiogenesis in the critical sized bone defects. Both insertion of the vascular bundle alone and BMP-2 loading alone induced comparable levels of angiogenesis and when used in combination, significantly greater vascular volume was observed. These findings suggest a promising new modality of treatment in large bone defects.

  View details for DOI 10.1089/ten.TEA.2021.0049

  View details for PubMedID 33906392

• Investigation of a Prevascularized Bone Graft for Large Defects in the Ovine Tibia. Tissue engineering. Part A Yang, Y. P., Gadomski, B., Bruyas, A., Easley, J. T., Labus, K., Brad, N., Palmer, R., Stewart, H., McGilvray, K., Puttlitz, C., Regan, D., Stahl, A., Lui, E., Li, J., Moeinzadeh, S., Kim, S., Maloney, W., Gardner, M. 2021

  Abstract

  In vivo bioreactors are a promising approach for engineering vascularized autologous bone grafts to repair large bone defects. In this pilot parametric study, we first developed a 3D printed scaffold uniquely designed to accommodate inclusion of a vascular bundle and facilitate growth factor delivery for accelerated vascular invasion and ectopic bone formation. Second, we established a new sheep deep circumflex iliac artery (DCIA) model as an in vivo bioreactor for engineering a vascularized bone graft and evaluated the effect of implantation duration on ectopic bone formation. Third, after 8 weeks of implantation around the DCIA, we transplanted the prevascularized bone graft to a 5 cm segmental bone defect in the sheep tibia, using the custom 3D printed BMP-2 loaded scaffold without prior in vivo bioreactor maturation as a control. Analysis by micro-computed tomography and histomorphometry found ectopic bone formation in BMP-2 loaded scaffolds implanted for 8 and 12 weeks in the iliac pouch, with greater bone formation occurring after 12 weeks. Grafts transplanted to the tibial defect supported bone growth, mainly on the periphery of the graft, but greater bone growth and less soft tissue invasion was observed in the avascular BMP-2 loaded scaffold implanted directly into the tibia without prior in vivo maturation. Histopathological evaluation noted considerably greater vascularity in the bone grafts that underwent in vivo maturation with an inserted vascular bundle compared to the avascular BMP-2 loaded graft. Our findings indicate that use of an initial DCIA in vivo bioreactor maturation step is a promising approach to developing vascularized autologous bone grafts, although scaffolds with greater osteoinductivity should be further studied.

  View details for DOI 10.1089/ten.TEA.2020.0347

  View details for PubMedID 33858216

• Osteoinductive 3D printed scaffold healed 5cm segmental bone defects in the ovine metatarsus. Scientific reports Yang, Y. P., Labus, K. M., Gadomski, B. C., Bruyas, A., Easley, J., Nelson, B., Palmer, R. H., McGilvray, K., Regan, D., Puttlitz, C. M., Stahl, A., Lui, E., Li, J., Moeinzadeh, S., Kim, S., Maloney, W., Gardner, M. J. 2021; 11 (1): 6704

  Abstract

  Autologous bone grafts are considered the gold standard grafting material for the treatment of nonunion, but in very large bone defects, traditional autograft alone is insufficient to induce repair. Recombinant human bone morphogenetic protein 2 (rhBMP-2) can stimulate bone regeneration and enhance the healing efficacy of bone grafts. The delivery of rhBMP-2 may even enable engineered synthetic scaffolds to be used in place of autologous bone grafts for the treatment of critical size defects, eliminating risks associated with autologous tissue harvest. We here demonstrate that an osteoinductive scaffold, fabricated by combining a 3D printed rigid polymer/ceramic composite scaffold with an rhBMP-2-eluting collagen sponge can treat extremely large-scale segmental defects in a pilot feasibility study using a new sheep metatarsus fracture model stabilized with an intramedullary nail. Bone regeneration after 24weeks was evaluated by micro-computed tomography, mechanical testing, and histological characterization. Load-bearing cortical bridging was achieved in all animals, with increased bone volume observed in sheep that received osteoinductive scaffolds compared to sheep that received an rhBMP-2-eluting collagen sponge alone.

  View details for DOI 10.1038/s41598-021-86210-5

  View details for PubMedID 33758338

• Modified Kerboul Angle Predicts Outcome of Core Decompression With or Without Additional Cell Therapy. The Journal of arthroplasty Boontanapibul, K., Huddleston, J. I., Amanatullah, D. F., Maloney, W. J., Goodman, S. B. 2021

  Abstract

  BACKGROUND: Core decompression is the most common procedure for early-stage osteonecrosis of the femoral head (ONFH). This study investigated outcomes of core decompression with/without bone marrow aspirate concentrate (BMAC), based on the Kerboul combined necrotic angles using magnetic resonance imaging.METHODS: We reviewed 66 patients (83 hips) with early ONFH, Association Research Circulation Osseous stages I-IIIa, who underwent core decompression alone (26 patients, 33 hips) or in combination with BMAC (40 patients, 50 hips). Survival rate and progressive collapse were analyzed using the Kaplan-Meier method, and conversion to total hip arthroplasty (THA) was evaluated. Subgroup analyses based on the modified Kerboul angle were performed: grade I (<200°), grade II (200°-249°), grade III (250°-299°), and grade IV (≥300°).RESULTS: Mean follow-up was 36±23 months. Femoral head collapse with BMAC (16 hips, 32%) was significantly lower than without BMAC (19 hips, 58%, P= .019). Conversion THA was significantly lower with BMAC (28%) than without (58%, P= .007). Survival rates among groups showed significant differences (P= .017). In grade I, 0/12 hips with BMAC collapsed while 3/9 (33%) without BMAC collapsed (P= .063); in grade II, 2/16 hips (12%) with BMAC collapsed while 7/13 (54%) without BMAC collapsed (P= .023). There was no significant difference in collapse with (64%) or without (82%) BMAC in grade III-IV hips (P= .256).CONCLUSION: Core decompression with/without BMAC had a high failure rate, by increasing disease progression and the necessity for THA, for combined necrotic angles >250°. In our study, addition of BMAC had more reliable outcomes than isolated core decompression for precollapse ONFH if the combined necrotic angles were <250°.

  View details for DOI 10.1016/j.arth.2021.01.075

  View details for PubMedID 33618954

• Response to Letter to the Editor on "Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology". The Journal of arthroplasty Boontanapibul, K. n., Steere, J. T., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2021; 36 (2): e12–e13

  View details for DOI 10.1016/j.arth.2020.09.037

  View details for PubMedID 33446355

• Provider Personal and Demographic Characteristics and Patient Satisfaction in Orthopaedic Surgery. Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews Lu, L. Y., Sharabianlou Korth, M. J., Cheng, R. Z., Finlay, A. K., Kamal, R. N., Goodman, S. B., Maloney, W. J., Huddleston, J. I., Amanatullah, D. F. 2021; 5 (4)

  Abstract

  INTRODUCTION: Patient satisfaction has increasingly been used to assess physician performance and quality of care. Although there is evidence that patient satisfaction is associated with patient-reported health outcomes and communication-related measures, there is debate over the use of patient satisfaction in reimbursement policy. Patient characteristics that influence satisfaction have been studied, but the effects of personal and demographic characteristics of physicians on patient satisfaction have yet to be explored.METHODS: Outpatient satisfaction scores from 11,059 patients who rated 25 orthopaedic surgeons from a single institution were studied. In this study, we sought to explore the relationship between nonmodifiable physician characteristics, such as sex and race, and patient satisfaction with outpatient orthopaedic surgery care, as expressed in the Press Ganey Satisfaction Scores. Univariate logistic regression models were used to test the associations between each provider characteristic and patient satisfaction on the Press Ganey patient satisfaction questionnaire.RESULTS: Three nonmodifiable physician personal and demographic characteristics were markedly associated with lower patient satisfaction scores across overall satisfaction, communication, and empathy domains: (1) female gender, (2) Asian ethnicity, and (3) being unmarried. Asian ethnicity reduced the odds of receiving a 5-star rating for likelihood to recommend the provider by nearly 40%, but none of these nonmodifiable physician personal and demographic characteristics affected the likelihood to recommend the practice.DISCUSSION: Sex, ethnicity, and marital status are nonmodifiable provider characteristics, each associated with markedly lower odds of receiving a 5-star rating on Press Ganey patient satisfaction survey. These data reveal inherent patient biases that negatively affect physician-patient interactions and may exacerbate the lack of diversity in orthopaedic surgery. More research is necessary before using patient satisfaction ratings to evaluate surgeons or as quality measures that affect reimbursement policies.

  View details for DOI 10.5435/JAAOSGlobal-D-20-00198

  View details for PubMedID 33835991

• Efficacy of motivational-interviewing and guided opioid tapering support for patients undergoing orthopedic surgery (MI-Opioid Taper): A prospective, assessor-blind, randomized controlled pilot trial. EClinicalMedicine Hah, J. M., Trafton, J. A., Narasimhan, B., Krishnamurthy, P., Hilmoe, H., Sharifzadeh, Y., Huddleston, J. I., Amanatullah, D., Maloney, W. J., Goodman, S., Carroll, I., Mackey, S. C. 2020; 28: 100596

  Abstract

  Background: Postoperative opioid use can lead to chronic use and misuse. Few studies have examined effective approaches to taper postoperative opioid use while maintaining adequate analgesia.Methods: This randomized, assessor-blinded, pilot trial of postoperative motivational interviewing and guided opioid tapering support (MI-Opioid Taper) added to usual care (UC) enrolled patients undergoing total hip or knee arthroplasty at a single U.S. academic medical center. MI-Opioid Taper involved weekly (to seven weeks) and monthly (to one year) phone calls until patient-reported opioid cessation. Opioid tapering involved 25% weekly dose reductions. The primary feasibility outcome was study completion in the group to which participants were randomized. The primary efficacy outcome, time to baseline opioid use, was the first of five consecutive days of return to baseline preoperative dose. Intention-to-treat analysis with Cox proportional hazards regression was adjusted for operation. ClinicalTrials.gov registration: NCT02070003.Findings: From November 26, 2014, to April 27, 2018, 209 patients were screened, and 104 patients were assigned to receive MI-Opioid Taper (49 patients) or UC only (55 patients). Study completion after randomization was similar between groups (96.4%, 53 patients receiving UC, 91.8%, 45 patients receiving MI-Opioid Taper). Patients receiving MI-Opioid Taper had a 62% increase in the rate of return to baseline opioid use after surgery (HR 1.62; 95%CI 1.06-2.46; p=003). No trial-related adverse events occurred.Interpretation: In patients undergoing total joint arthroplasty, MI-Opioid Taper is feasible and future research is needed to establish the efficacy of MI-Opioid Taper to promote postoperative opioid cessation.Funding: National Institute on Drug Abuse.

  View details for DOI 10.1016/j.eclinm.2020.100596

  View details for PubMedID 33294812

• Incidence and Characteristics of Osteolysis in HXLPE THA at 16-Year Follow up in Patients 50 Years and Less. The Journal of arthroplasty Rames, R. D., Hillen, T. J., Pashos, G. E., Maloney, W. J., Clohisy, J. C. 2020

  Abstract

  INTRODUCTION: Young patients present a challenge for total hip arthroplasty (THA) survivorship. Highly cross-linked polyethylene (HXLPE) liners have decreased the prevalence of osteolysis; however, concerns exist regarding the biologic activity of wear particles. The purpose of this study was to determine the incidence and characteristics of osteolytic lesions in young HXLPE THA patients at an average 16-year follow up and determine the ability to detect osteolysis.METHODS: We performed a retrospective study involving 22 patients (26 THA) under age 50 at primary THA receiving HXLPE liners coupled with cobalt-chrome (CoCr) femoral heads. Computed tomography (CT) scans were reviewed for osteolysis. Chi-squared analysis was used for categorical variables and unpaired Kruskal-Wallis rank-sum test for continuous variables. Logistic regression was used to compare wear rates between those patients with and without osteolysis.RESULTS: The mean age at surgery was 38.5 years. The mean time from surgery to CT scan was sixteen years (range 14.25-19.5 years). Nine of the 26 THA showed osteolysis. The mean volume of the lesions was 2.8 cm3. Linear (mean 0.008 mm/y) and volumetric (mean 4.5 mm3/year) wear rates were negligible. One-third of osteolytic lesions were visible on radiographs. Logistic regression failed to demonstrate a correlation between wear rates or UCLA activity score and osteolysis.CONCLUSION: We observed osteolysis in 35% of HXLPE THA in young patients at mean 16-year follow up despite zero revisions for wear-related problems and clinically insignificant wear rates.LEVEL OF EVIDENCE: IV.

  View details for DOI 10.1016/j.arth.2020.08.048

  View details for PubMedID 32948423

• Effect Of Triamcinolone Acetonide Extended-release On Synovial Inflammation In Patients With Osteoarthritis Of The Knee Kelley, S., Huffman, K., Conaghan, P., Bowes, M., Cinar, A., Kivitz, A., Kraus, V., Maloney, W., Parvizi, J., Brett, A., Bodick, N. LIPPINCOTT WILLIAMS & WILKINS. 2020: 1010

  View details for Web of Science ID 000590026304361

• Selective screw fixation is associated with early failure of primary acetabular components for aseptic loosening. Journal of orthopaedic research : official publication of the Orthopaedic Research Society Henry Goodnough, L., Bonano, J. C., Finlay, A. K., Aggarwal, V., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2020

  Abstract

  Selective augmentation of the acetabular component with screws during primary total hip arthroplasty (THA) assumes that the surgeon can detect when an acetabular component needs added stability. In contrast, non-selective screw users do not alter their practice based on their interpretation of stability and either use screws all or none of the time. We aimed to determine the effect of selective screw use on aseptic acetabular component loosening. We retrospectively reviewed aseptic failures of THA acetabular components. We compared the survivorship of selective to non-selective supplementation of acetabular fixation with screws, and compared time to revision, obesity and selective screw use. Selective screw use (n=16) was associated with earlier acetabular component aseptic loosening (median 1.9 years; interquartile range (IQR) 1.1-5.0) compared to non-selective screw use (n=22; median 5.6 years; IQR 2.0- 15.3, p = 0.010). Selective screw use was independently associated with earlier revision after adjusting for patient obesity. Obesity was associated with selective screw use in 50% of the cases versus 14% of non-selective cases (OR 6.3 CI 1.2-25.2, p = 0.028), possibly reflecting the increased difficulty in achieving acetabular component stability in this and other settings with compromised bone. Surgeons should carefully assess component stability at time of primary THA. If the acetabulum is not stable, the addition of screws alone may not be sufficient for acetabular component stability. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/jor.24649

  View details for PubMedID 32157712

• Reimbursement and Complications in Outpatient vs Inpatient Unicompartmental Arthroplasty. The Journal of arthroplasty Bosch, L. C., Bala, A., Denduluri, S. K., Maloney, W. J., Huddleston, J. I., Goodman, S. B., Amanatullah, D. F. 2020

  Abstract

  BACKGROUND: Increasing utilization of unicompartmental knee arthroplasty (UKA) has driven a greater push for outpatient treatment and cost containment in the setting of bundled payments. The purpose of this study is to evaluate utilization trends of inpatient vs outpatient UKA, index episode and 90-day reimbursement, and any differences in medical or surgical complications.METHODS: The PearlDiver database was employed to identify all inpatient and outpatient UKAs performed between 2007 and 2016 with 2-year follow-up. Patients were matched by age, gender, and Elixhauser Comorbidity Index. We tracked index procedure and global period reimbursement, 90-day medical and surgical complications, and 2-year surgical complications.RESULTS: The reimbursement and utilization cohort included 3181 outpatient and 5490 inpatient UKAs. Outpatient UKA and overall utilization of UKA increased over the study period. Mean index reimbursement of inpatient UKA was $2486.16 higher per procedure (P < .001) while mean global period reimbursement was $2782.13 higher per inpatient procedure (P < .001). Ninety-day medical complications including postoperative anemia (P < .001), transfusion (P= .024), and arrhythmia (P= .004) were more common with inpatient UKAs, whereas surgical wound complications (P= .001) and operative debridement (P= .028) were more common among outpatient UKAs. Outpatient UKA was not associated with an increased risk of periprosthetic joint infection (P > .05), aseptic loosening (P > .05), or revision surgery (P > .05) when compared to inpatient UKA.CONCLUSION: Outpatient UKA utilization is increasing and is associated with decreased reimbursement compared to inpatient UKA without increased risk of major medical complications, although it is associated with increased risk of wound complication and need for operative debridement at 90 days.

  View details for DOI 10.1016/j.arth.2020.02.063

  View details for PubMedID 32220483

• Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology. The Journal of arthroplasty Boontanapibul, K. n., Steere, J. T., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2020

  Abstract

  Joint preservation is more effective in early-stage osteonecrosis of the femoral head (ONFH); thus, prompt diagnosis when the femoral head is still salvageable is important. We report a 20-year retrospective study that summarizes age at presentation, etiology, and Association Research Circulation Osseous stage at diagnosis.Our database was reviewed to identify patients younger than 65 years of age who were diagnosed with atraumatic ONFH between 1998 and 2018. Demographic characteristics of patients were evaluated and categorized into different subgroups.Four hundred thirteen patients were identified. At initial presentation, 23% were diagnosed with early-stage ONFH, while 77% were diagnosed with late-stage ONFH. Forty-nine percent had a history of corticosteroid use, of which 13% were diagnosed with hematologic malignancy and 8% were diagnosed with lupus. Ethanol abuse, idiopathic, sickle cell disease, and human immunodeficiency virus were present in 11%, 30%, 3%, and 3%, respectively. The mean age of patients with corticosteroid use (40 ± 14 years) was significantly younger than ethanol use (46 ± 11 years, P = .014) and idiopathic causes (48 ± 11 years, P < .001), but significantly older than sickle cell disease (32 ± 11 years, P = .031). There was no difference in the age of presentation for early-stage and late-stage ONFH by etiology.Nearly 80% of the patients presented with late-stage ONFH. Hence, we have a narrow window of opportunity for hip preservation surgery before femoral head collapse. A multidisciplinary approach to improve screening awareness for early detection by focusing on the etiologic identification and patient education might reduce the incidence of hip arthroplasty in young patients.

  View details for DOI 10.1016/j.arth.2020.04.092

  View details for PubMedID 32456965

• The routine use of synovial alpha-defensin is not necessary. The bone & joint journal Amanatullah, D. F., Cheng, R. Z., Huddleston Iii, J. I., Maloney, W. J., Finlay, A. K., Kappagoda, S. n., Suh, G. A., Goodman, S. B. 2020; 102-B (5): 593–99

  Abstract

  To establish the utility of adding the laboratory-based synovial alpha-defensin immunoassay to the traditional diagnostic work-up of a prosthetic joint infection (PJI).A group of four physicians evaluated 158 consecutive patients who were worked up for PJI, of which 94 underwent revision arthroplasty. Each physician reviewed the diagnostic data and decided on the presence of PJI according to the 2014 Musculoskeletal Infection Society (MSIS) criteria (yes, no, or undetermined). Their initial randomized review of the available data before or after surgery was blinded to each alpha-defensin result and a subsequent randomized review was conducted with each result. Multilevel logistic regression analysis assessed the effect of having the alpha-defensin result on the ability to diagnose PJI. Alpha-defensin was correlated to the number of synovial white blood cells (WBCs) and percentage of polymorphonuclear cells (%PMN).Intraobserver reliability and interobserver agreement did not change when the alpha-defensin result was available. Positive alpha-defensin results had greater synovial WBCs (mean 31,854 cells/μL, SD 32,594) and %PMN (mean 93.0%, SD 5.5%) than negative alpha-defensin results (mean 974 cells/μL, SD 3,988; p < 0.001 and mean 39.4% SD 28.6%; p < 0.001). Adding the alpha-defensin result did not alter the diagnosis of a PJI using preoperative (odds ratio (OR) 0.52, 95% confidence interval (CI) 0.14 to 1.88; p = 0.315) or operative (OR 0.52, CI 0.18 to 1.55; p = 0.242) data when clinicians already decided that PJI was present or absent with traditionally available testing. However, when undetermined with traditional preoperative testing, alpha-defensin helped diagnose (OR 0.44, CI 0.30 to 0.64; p < 0.001) or rule out (OR 0.41, CI 0.17 to 0.98; p = 0.044) PJI. Of the 27 undecided cases with traditional testing, 24 (89%) benefited from the addition of alpha-defensin testing.The laboratory-based synovial alpha-defensin immunoassay did not help diagnose or rule out a PJI when added to routine serologies and synovial fluid analyses except in cases where the diagnosis of PJI was unclear. We recommend against the routine use of alpha-defensin and suggest using it only when traditional testing is indeterminate. Cite this article: Bone Joint J 2020;102-B(5):593-599.

  View details for DOI 10.1302/0301-620X.102B5.BJJ-2019-0473.R3

  View details for PubMedID 32349594

• Preoperative Factors Associated with Remote Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: Post Hoc Analysis of a Perioperative Gabapentin Trial. Journal of pain research Hah, J. M., Hilmoe, H. n., Schmidt, P. n., McCue, R. n., Trafton, J. n., Clay, D. n., Sharifzadeh, Y. n., Ruchelli, G. n., Hernandez Boussard, T. n., Goodman, S. n., Huddleston, J. n., Maloney, W. J., Dirbas, F. M., Shrager, J. n., Costouros, J. G., Curtin, C. n., Mackey, S. C., Carroll, I. n. 2020; 13: 2959–70

  Abstract

  Preoperative patient-specific risk factors may elucidate the mechanisms leading to the persistence of pain and opioid use after surgery. This study aimed to determine whether similar or discordant preoperative factors were associated with the duration of postoperative pain and opioid use.In this post hoc analysis of a randomized, double-blind, placebo-controlled trial of perioperative gabapentin vs active placebo, 410 patients aged 18-75 years, undergoing diverse operations underwent preoperative assessments of pain, opioid use, substance use, and psychosocial variables. After surgery, a modified Brief Pain Inventory was administered over the phone daily up to 3 months, weekly up to 6 months, and monthly up to 2 years after surgery. Pain and opioid cessation were defined as the first of 5 consecutive days of 0 out of 10 pain or no opioid use, respectively.Overall, 36.1%, 19.8%, and 9.5% of patients continued to report pain, and 9.5%, 2.4%, and 1.7% reported continued opioid use at 3, 6, and 12 months after surgery. Preoperative pain at the future surgical site (every 1-point increase in the Numeric Pain Rating Scale; HR 0.93; 95% CI 0.87-1.00; P=0.034), trait anxiety (every 10-point increase in the Trait Anxiety Inventory; HR 0.79; 95% CI 0.68-0.92; P=0.002), and a history of delayed recovery after injury (HR 0.62; 95% CI 0.40-0.96; P=0.034) were associated with delayed pain cessation. Preoperative opioid use (HR 0.60; 95% CI 0.39-0.92; P=0.020), elevated depressive symptoms (every 5-point increase in the Beck Depression Inventory-II score; HR 0.88; 95% CI 0.80-0.98; P=0.017), and preoperative pain outside of the surgical site (HR 0.94; 95% CI 0.89-1.00; P=0.046) were associated with delayed opioid cessation, while perioperative gabapentin promoted opioid cessation (HR 1.37; 95% CI 1.06-1.77; P=0.016).Separate risk factors for prolonged post-surgical pain and opioid use indicate that preoperative risk stratification for each outcome may identify patients needing personalized care to augment universal protocols for perioperative pain management and conservative opioid prescribing to improve long-term outcomes.

  View details for DOI 10.2147/JPR.S269370

  View details for PubMedID 33239904

  View details for PubMedCentralID PMC7680674

• Initial Presentation and Progression of Secondary Osteonecrosis of the Knee. The Journal of arthroplasty Boontanapibul, K. n., Steere, J. T., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2020

  Abstract

  Early detection and intervention are critical to maintaining the native articular cartilage before collapse in secondary osteonecrosis of the knee (SOK). We conducted a retrospective study documenting the initial stage of presentation and the progression of SOK.Our database was reviewed for patients younger than 65 years of age diagnosed with atraumatic SOK between 2002 and 2018. Demographic data, plain radiographs as well as MRI at initial evaluation, and initial treatment were classified and analyzed.One hundred four patients with 164 knees were identified. Mean age was 39 ± 16 years. Females (64%) with bilateral disease (58%) predominated. Seventy-five percent of patients had a history of corticosteroid use, of which 41% were diagnosed with hematologic malignancy and lupus. Fifteen percent of patients had a history of ethanol abuse. At initial presentation, 55% of patients were diagnosed with Ficat-Arlet stage I/II, while 45% were diagnosed with Ficat-Arlet stage III/IV. We found a significant difference in the mean age of patients at early stage of SOK with corticosteroid use (31 ± 12 years of age) when compared to ethanol use (43 ± 13 years of age, P = .02). Treatments included observation (57%), joint preservation surgery (20%), and total knee arthroplasty (23%).Nearly half of patients presented at late stage compromising the potential for joint preservation. The difference in age of referral by over a decade, based on etiology of SOK, suggests a strong provider-based referral or screening bias may be present. Hence, a multidisciplinary approach to earlier detection and referral may be a more effective strategy for preventing the progression of SOK.

  View details for DOI 10.1016/j.arth.2020.05.020

  View details for PubMedID 32527695

• Reply to Letter to the Editor on "Mental Health Status Improves Following Total Knee Arthroplasty". The Journal of arthroplasty Horst, P. K., Barrett, A. A., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2020

  View details for DOI 10.1016/j.arth.2020.05.067

  View details for PubMedID 32571590

• Synthetic bone tissue engineering graft substitutes: What is the future? Injury Valtanen, R. S., Yang, Y. P., Gurtner, G. C., Maloney, W. J., Lowenberg, D. W. 2020

  Abstract

  The management of large segmental bone defects caused by trauma or disease remains clinically challenging within orthopaedics. The major impediment to bone healing with current treatment options is insufficient vascularization and incorporation of graft material. Lack of rapid adequate vascularization leads to cellular necrosis within the inner regions of the implanted material and a failure of bone regeneration. Current treatment options for critical size bone defects include the continued "gold standard" autograft, allograft, synthetic bone graft substitutes, vascularized fibular graft, induced membrane technique, and distraction osteogenesis. Bone tissue engineering (BTE) remains an exciting prospect for the treatment of large segmental bone defects; however, current clinical integration of engineered scaffolds remains low. We believe that the barrier to clinical application of bone tissue engineering constructs lies in the lack of concomitant vascularization of these scaffolds. This mini-review outlines the progress made and the significant limitations remaining in successful clinical incorporation or engineered synthetic bone substitutes for segmental defects.

  View details for DOI 10.1016/j.injury.2020.07.040

  View details for PubMedID 32732118

• Outcomes of Cemented Total Knee Arthroplasty for Secondary Osteonecrosis of the Knee. The Journal of arthroplasty Boontanapibul, K. n., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2020

  Abstract

  Secondary osteonecrosis of the knee (SOK) generally occurs in relatively young patients; at advanced stages of SOK, the only viable surgical option is total knee arthroplasty (TKA). We conducted a retrospective study to investigate implant survivorship, clinical and radiographic outcomes, and complications of contemporary cemented bicompartmental TKA with/without patellar resurfacing for SOK.Thirty-eight cemented TKAs in 27 patients with atraumatic SOK, mean age 43 years (17 to 65), were retrospectively reviewed. Seventy-four percent had a history of corticosteroid use, and 18% had a history of alcohol abuse. Patellar osteonecrosis was coincidentally found in six knees (16%), and all were asymptomatic without joint collapse. The mean followup was 7 years (2 to 12). Knee Society Score (KSS) and radiographic outcomes were evaluated at 6 weeks, 1 year, then every 2 to 3 years.Ninety-two percent had implant survivorship free from revision with significant improvement in KSS. Causes of revision included aseptic tibial loosening (one), deep infection (one), and instability with patellofemoral issues (one). Four of six cases also with patellar osteonecrosis received resurfacing, including one with periprosthetic patellar fracture after minor trauma, with satisfactory clinical results after conservative treatment. None of the unrevised knees had progressive radiolucent lines or evidence of loosening. An unresurfaced patella, use of a stem extension or a varus-valgus constrained prosthesis constituted 18%, 8% and 3%, respectively.Cemented TKAs with selective stem extension in patients with SOK had satisfactory implant survivorship and reliable outcomes. Secondary osteonecrosis of the patella should be carefully evaluated prior to operation.

  View details for DOI 10.1016/j.arth.2020.08.061

  View details for PubMedID 33011011

• Statin use is associated with less postoperative cardiac arrhythmia after total hip arthroplasty HIP INTERNATIONAL Chen, M. J., Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Aaronson, A. J., Amanatullah, D. F. 2019; 29 (6): 618–23

  View details for DOI 10.1177/1120700018816091

  View details for Web of Science ID 000487029700010

• Response to Letter to the Editor on "Total Knee Arthroplasty Has Positive Effect on Patients With Low Mental Health Scores". The Journal of arthroplasty Horst, P. K., Barrett, A. A., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2019

  View details for DOI 10.1016/j.arth.2019.10.047

  View details for PubMedID 31785963

• Total Knee Arthroplasty Has A Positive Effect on Patients With Low Mental Health Scores. The Journal of arthroplasty Horst, P. K., Barrett, A. A., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2019

  Abstract

  BACKGROUND: The purpose of this study is to determine the impact of total knee arthroplasty (TKA) on mental health.METHODS: A total of 205 patients who underwent primary TKA with baseline and 1-year postoperative Short Form-12 Mental Component Score (MCS) were included in this retrospective analysis. Eighty-five (41%) patients had a preoperative MCS less than 50 points, while 120 (59%) patients had a preoperative MCS over 50 points. Two groups were assigned to the patients based on their preoperative MCS: low MCS <50 and high MCS >50.RESULTS: A preoperative MCS less than 50 points was predictive of greater improvement in MCS at 1 year after TKA (P < .001). Patients with low MCS improved by a mean of 10.6 points from 39.1 ± 8.6 points preoperatively to mean of 49.7 ± 10.7 points 1 year after TKA (P < .001). Patients with a high MCS decreased by a mean of 3.5 points from 60.01 ± 6.0 points preoperatively to mean of 56.6 ± 6.8 points 1 year after TKA (P < .001). This remained higher than the postoperative MCS of the patients with a low MCS, 49.7 ± 10.7 (P < .001). The patients with a high MCS had greater improvement in the Short Form-12-Physical domain (14.8 points) than the patients with a low MCS (9.2 points, P < .001).CONCLUSION: Patients with lower baseline mental health had greater improvement in postoperative mental health following TKA than patients with higher baseline mental health. Low preoperative MCS was associated with less improvement in patient-reported outcome measures. Patients with lower baseline mental health scores before TKA benefit mentally and physically from the procedure.

  View details for DOI 10.1016/j.arth.2019.08.033

  View details for PubMedID 31522853

• Improved Range of Motion and Patient-Reported Outcome Scores With Fixed-Bearing Revision Total Knee Arthroplasty for Suboptimal Axial Implant Rotation JOURNAL OF ARTHROPLASTY Amanatullah, D. E., Lichstein, P. M., Lundergan, W. G., Wong, W. W., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2019; 34 (6): 1174–78

  View details for DOI 10.1016/j.arth.2019.02.007

  View details for Web of Science ID 000468307600024

• Computer Navigation vs Conventional Total Hip Arthroplasty: AMedicare Database Analysis. The Journal of arthroplasty Montgomery, B. K., Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2019

  Abstract

  BACKGROUND: Computer-assisted surgery (CAS) is applied to total hip arthroplasty (THA) in an attempt to optimize implant positioning. The effect of CAS on postoperative complications after THA remains unknown. Our study aims to assess the change in complication rates when CAS is used in THA.METHODS: The Medicare database was studied from 2005 to 2012. All THAs performed with CAS were identified. A total of 64,944 THAs were identified, including 5412 CAS-THAs and 59,532 conventional THAs. Medical and surgical adverse events were collected at various time points.RESULTS: CAS-THA was not associated with a decreased rate of dislocation at 30 days (1.0% vs 1.2%; odds ratio [OR], 1.14; P= .310), 90 days (1.1% vs 1.4%; OR, 1.23; P= .090), or 2 years (2.3% vs 2.3%; OR, 1.01; P= .931). CAS-THA was associated with a significantly higher rate of periprosthetic fracture at 30 days (0.4% vs 0.6%; OR, 1.46; P= .040) as well as revision THA at 30 days (1.0% vs 1.4%; OR, 1.43; P= .003) and 90 days (1.2% vs 1.7%; OR, 1.42; P < .002) when compared to conventional THA. CAS-THA was associated with a significantly lower rate of deep vein thrombosis and pulmonary embolism when compared to conventional THA at all time points (P < .05).CONCLUSION: Administrative coding data fail to demonstrate any clinically significant reduction in short-term adverse events with CAS-THA. Further study is warranted to evaluate whether the purported benefits of CAS result in a reduction of the adverse events after THA.

  View details for DOI 10.1016/j.arth.2019.04.063

  View details for PubMedID 31176561

• Venous thromboprophylaxis after total hip arthroplasty: aspirin, warfarin, enoxaparin, or factor Xa inhibitors? Hip international : the journal of clinical and experimental research on hip pathology and therapy Bala, A., Murasko, M. J., Burk, D. R., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2019: 1120700019841600

  Abstract

  INTRODUCTION: Debate over the ideal agent for venous thromboembolism (VTE) prophylaxis after total hip arthroplasty (THA) has led to changes in prescribing trends of commonly used agents. We investigate variation in utilisation and the differences in VTE incidence and bleeding risk in primary THA after administration of aspirin, warfarin, enoxaparin, or factor Xa inhibitors.METHODS: 8829 patients were age/sex matched from a large database of primary THAs performed between 2007 and 2016. Utilisation was calculated using compound annual growth rate. Incidence of postoperative deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding-related complications, postoperative anaemia, and transfusion were identified at 2weeks, 30days, 6weeks, and 90days.RESULTS: Aspirin use increased by 33%, enoxaparin by 7%, and factor Xa inhibitors by 31%. Warfarin use decreased by 1%. Factor Xa inhibitors (1.7%) and aspirin (1.7%) had the lowest incidence of DVT followed by enoxaparin (2.6%), and warfarin (3.7%) at 90days. Factor Xa inhibitors (12%) and aspirin (12%) had the lowest incidence of blood transfusion followed by warfarin (15%) and enoxaparin (17%) at 90 days. There was no difference in incidence of blood transfusion or bleeding-related complications nor any detectable difference in symptomatic PE incidence.CONCLUSIONS: The utilisation of aspirin and factor Xa inhibitors increased over time. Aspirin and factor Xa inhibitors provided improved DVT prophylaxis with lower rates of postoperative anaemia compared to enoxaparin and warfarin.

  View details for DOI 10.1177/1120700019841600

  View details for PubMedID 30990095

• Factors Associated With Acute Pain Estimation, Postoperative Pain Resolution, Opioid Cessation, and Recovery Secondary Analysis of a Randomized Clinical Trial JAMA NETWORK OPEN Hah, J. M., Cramer, E., Hilmoe, H., Schmidt, P., McCue, R., Trafton, J., Clay, D., Sharifzadeh, Y., Ruchelli, G., Goodman, S., Huddleston, J., Maloney, W. J., Dirbas, F. M., Shrager, J., Costouros, J. G., Curtin, C., Mackey, S. C., Carroll, I. 2019; 2 (3)

  View details for DOI 10.1001/jamanetworkopen.2019.0168

  View details for Web of Science ID 000465424000048

• Factors Associated With Acute Pain Estimation, Postoperative Pain Resolution, Opioid Cessation, and Recovery: Secondary Analysis of a Randomized Clinical Trial. JAMA network open Hah, J. M., Cramer, E., Hilmoe, H., Schmidt, P., McCue, R., Trafton, J., Clay, D., Sharifzadeh, Y., Ruchelli, G., Goodman, S., Huddleston, J., Maloney, W. J., Dirbas, F. M., Shrager, J., Costouros, J. G., Curtin, C., Mackey, S. C., Carroll, I. 2019; 2 (3): e190168

  Abstract

  Importance: Acute postoperative pain is associated with the development of persistent postsurgical pain, but it is unclear which aspect is most estimable.Objective: To identify patient clusters based on acute pain trajectories, preoperative psychosocial characteristics associated with the high-risk cluster, and the best acute pain predictor of remote outcomes.Design, Setting, and Participants: A secondary analysis of the Stanford Accelerated Recovery Trial randomized, double-blind clinical trial was conducted at a single-center, tertiary, referral teaching hospital. A total of 422 participants scheduled for thoracotomy, video-assisted thoracoscopic surgery, total hip replacement, total knee replacement, mastectomy, breast lumpectomy, hand surgery, carpal tunnel surgery, knee arthroscopy, shoulder arthroplasty, or shoulder arthroscopy were enrolled between May 25, 2010, and July 25, 2014. Data analysis was performed from January 1 to August 1, 2018.Interventions: Patients were randomized to receive gabapentin (1200 mg, preoperatively, and 600 mg, 3 times a day postoperatively) or active placebo (lorazepam, 0.5 mg preoperatively, inactive placebo postoperatively) for 72 hours.Main Outcomes and Measures: A modified Brief Pain Inventory prospectively captured 3 surgical site pain outcomes: average pain and worst pain intensity over the past 24 hours, and current pain intensity. Within each category, acute pain trajectories (first 10 postoperative pain scores) were compared using a k-means clustering algorithm. Fifteen descriptors of acute pain were compared as predictors of remote postoperative pain resolution, opioid cessation, and full recovery.Results: Of the 422 patients enrolled, 371 patients (≤10% missing pain scores) were included in the analysis. Of these, 146 (39.4%) were men; mean (SD) age was 56.67 (11.70) years. Two clusters were identified within each trajectory category. The high pain cluster of the average pain trajectory significantly predicted prolonged pain (hazard ratio [HR], 0.63; 95% CI, 0.50-0.80; P<.001) and delayed opioid cessation (HR, 0.52; 95% CI, 0.41-0.67; P<.001) but was not a predictor of time to recovery in Cox proportional hazards regression (HR, 0.89; 95% CI, 0.69-1.14; P=.89). Preoperative risk factors for categorization to the high average pain cluster included female sex (adjusted relative risk [ARR], 1.36; 95% CI, 1.08-1.70; P=.008), elevated preoperative pain (ARR, 1.11; 95% CI, 1.07-1.15; P<.001), a history of alcohol or drug abuse treatment (ARR,1.90; 95% CI, 1.42-2.53; P<.001), and receiving active placebo (ARR, 1.27; 95% CI, 1.03-1.56; P=.03). Worst pain reported on postoperative day 10 was the best predictor of time to pain resolution (HR, 0.83; 95% CI, 0.78-0.87; P<.001), opioid cessation (HR, 0.84; 95% CI, 0.80-0.89; P<.001), and complete surgical recovery (HR, 0.91; 95% CI, 0.86-0.96; P<.001).Conclusions and Relevance: This study has shown a possible uniform predictor of remote postoperative pain, opioid use, and recovery that can be easily assessed. Future work is needed to replicate these findings.Trial Registration: ClinicalTrials.gov Identifier: NCT01067144.

  View details for PubMedID 30821824

• Improved Range of Motion and Patient-Reported Outcome Scores With Fixed-Bearing Revision Total Knee Arthroplasty for Suboptimal Axial Implant Rotation. The Journal of arthroplasty Amanatullah, D. F., Lichstein, P. M., Lundergan, W. G., Wong, W. W., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2019

  Abstract

  BACKGROUND: Suboptimal implant rotation has consequences with respect to knee kinematics and clinical outcomes. We evaluated the functional outcomes of revision total knee arthroplasty (TKA) for poor axial implant rotation.METHODS: We retrospectively reviewed 42 TKAs undergoing aseptic revision for poor axial implant rotation. We assessed improvements in Knee Society Score (KSS) and final range of motion (ROM). Subgroup analyses were performed for preoperative instability and stiffness, as well as the number of components revised and level of implant constraint used.RESULTS: Revision for poor axial rotation in isolation improved KSS from 52 ± 22 to 84 ± 25 (P < .001), and flexion increased from 105 ± 21° to 115 ± 13° (P = .001). Revision in the setting of instability significantly improved the KSS (P < .001) but did not affect ROM (P = .172). Revision in the setting of stiffness significantly improved both KSS (P < .001) and ROM (P = .002). There was no statistically significant difference between the postoperative KSS (P = .889) and final knee flexion (P = .629) with single- or both-component revision TKA for isolated poor axial rotation or between the postoperative KSS (P = .956) and final knee flexion (P = .541) with or without the use of higher constraint during revision TKA for isolated poor axial rotation.CONCLUSION: Revision TKA for poor axial alignment improves clinical outcomes scores and functional ROM.

  View details for PubMedID 30853158

• Fifteen-Year Results of Total Hip Arthroplasty With Cobalt-Chromium Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years and Less. The Journal of arthroplasty Rames, R. D., Stambough, J. B., Pashos, G. E., Maloney, W. J., Martell, J. M., Clohisy, J. C. 2019

  Abstract

  BACKGROUND: Highly cross-linked polyethylene (HXLPE) is the most commonly used bearing surface in total hip arthroplasty (THA) because of its superior wear properties, but long-term results in young patients are limited. Mid-term survivorship has been promising; however, polyethylene wear rates and need for revision surgeries remain a concern in this population. The purpose of our study is to investigate polyethylene wear rates, implant survivorship, wear-related revisions, and patient-reported outcomes in a young patient cohort at 15-year follow-up.METHODS: We performed a retrospective study of a prospective longitudinal cohort of 82 consecutive patients (89 hips) who underwent primary THA with an HXLPE acetabular liner and a cobalt-chromium femoral head. The mean age at the time of surgery for the cohort was 38.8 years (range 12-50). All patients received HXLPE liners with a cementless acetabular component coupled with a cobalt-chrome femoral head through a posterior approach with a cementless femoral component. All components were from a single manufacturer. We recorded University of California, Los Angeles Activity, and modified Harris Hip Scores. Wear calculations were made using the Martell Hip Analysis Suite (Version 8.0.4.3).RESULTS: At average 15 years (range 13.1-18.5), there was a revision-free survivorship of 97.8% in our HXLPE group with no wear-related revisions. We observed a linear wear rate of 0.0185 mm/y (standard deviation 0.05) after accounting for a 1-year bedding-in period. The volumetric wear rate was found to be 12.80 mm3/y (standard deviation 22.69). These numbers are registered as clinically undetectable and are comparable to steady state wear rates in the same cohort of patients at earlier time points. We found no radiographic changes concerning osteolysis. We observed excellent patient-reported outcomes at this time point with improvements in modified Harris Hip Scores (35.3 [22.5], P < .0001) and University of California, Los Angeles Activity Scores (median 6.0, P < .0001).CONCLUSION: At 15-year follow-up, we demonstrated that HXLPE bearings in this young cohort had excellent wear properties, maintained superior clinical improvements, and underwent no wear-related revision operations. The HXLPE and cobalt-chrome bearing couple continues to be extremely effective 15 years after primary THA in patients less than 50 years.LEVEL OF EVIDENCE: IV.

  View details for DOI 10.1016/j.arth.2019.01.071

  View details for PubMedID 30808529

• Hematopoietic PBX-interacting protein mediates cartilage degeneration during the pathogenesis of osteoarthritis. Nature communications Ji, Q., Xu, X., Kang, L., Xu, Y., Xiao, J., Goodman, S. B., Zhu, X., Li, W., Liu, J., Gao, X., Yan, Z., Zheng, Y., Wang, Z., Maloney, W. J., Ye, Q., Wang, Y. 2019; 10 (1): 313

  Abstract

  Osteoarthritis (OA) has been recognized as the most common chronic age-related disease. Cartilage degeneration influences OA therapy. Here we report that hematopoietic pre-B cell leukemia transcription factor-interacting protein (HPIP) is essential for OA development. Elevated HPIP levels are found in OA patients. Col2a1-CreERT2/HPIPf/f mice exhibit obvious skeletal abnormalities compared with their HPIPf/f littermates. HPIP deficiency in mice protects against developing OA. Moreover, intra-articular injection of adeno-associated virus carrying HPIP-specific short hairpin RNA in vivo attenuates OA histological signs. Notably, in vitro RNA-sequencing and chromatin immunoprecipitation sequencing profiles identify that HPIP modulates OA cartilage degeneration through transcriptional activation of Wnt target genes. Mechanistically, HPIP promotes the transcription of Wnt targets by interacting with lymphoid enhancer binding factor 1 (LEF1). Furthermore, HPIP potentiates the transcriptional activity of LEF1 and acetylates histone H3 lysine 56 in the promoters of Wnt targets, suggesting that HPIP is an attractive target in OA regulatory network.

  View details for PubMedID 30659184

• Optimizing Clinical Use of Biologics in Orthopaedic Surgery: Consensus Recommendations From the 2018 AAOS/NIH U-13 Conference JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS Chu, C. R., Rodeo, S., Bhutani, N., Goodrich, L. R., Huard, J., Irrgang, J., LaPrade, R. F., Lattermann, C., Lu, Y., Mandelbaum, B., Mao, J., McIntyre, L., Mishra, A., Muschler, G. F., Piuzzi, N. S., Potter, H., Spindler, K., Tokish, J. M., Tuan, R., Zaslav, K., Maloney, W. 2019; 27 (2): E50–E63

  Abstract

  Concern that misinformation from direct-to-consumer marketing of largely unproven "biologic" treatments such as platelet-rich plasma and cell-based therapies may erode the public trust and the responsible investment needed to bring legitimate biological therapies to patients have resulted in calls to action from professional organizations and governing bodies. In response to substantial patient demand for biologic treatment of orthopaedic conditions, the American Academy of Orthopaedic Surgeons convened a collaborative symposium and established a consensus framework for improving and accelerating the clinical evaluation, use, and optimization of biologic therapies for musculoskeletal diseases. The economic and disease burden of musculoskeletal conditions is high. Of the various conditions discussed, knee osteoarthritis was identified as a "serious condition" associated with substantial and progressive morbidity and emerged as the condition with the most urgent need for clinical trial development. It was also recognized that stem cells have unique characteristics that are not met by minimally manipulated mixed cell preparations. The work group recommended that minimally manipulated cell products be referred to as cell therapy and that the untested and uncharacterized nature of these treatments be clearly communicated within the profession, to patients, and to the public. Minimum standards for product characterization and clinical research should also be followed. A framework for developing clinical trials related to knee OA was agreed upon. In addition to recommendations for development of high-quality multicenter clinical trials, another important recommendation was that physicians and institutions offering biologic therapies commit to establishing high-quality patient registries and biorepository-linked registries that can be used for postmarket surveillance and quality assessments.

  View details for DOI 10.5435/JAAOS-D-18-00305

  View details for Web of Science ID 000462411800001

  View details for PubMedID 30300216

  View details for PubMedCentralID PMC6314629

• The Cost of Malnutrition in Total Joint Arthroplasty. The Journal of arthroplasty Bala, A. n., Ivanov, D. V., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2019

  Abstract

  Malnutrition is a known risk factor for complications and adverse outcomes after elective total joint arthroplasty (TJA), but little is known about the burden this risk factor places on the healthcare system. The purpose of this study was to evaluate the 90-day impact of malnutrition on medical and surgical complications and understand the increase in global reimbursements associated with TJA in malnourished patients.We queried a combined private-payer and Medicare database from 2007 to 2016 for TJA using International Classification of Diseases, 9th revision and Current Procedural Terminology codes. Patients with serum albumin level of <3.5 g/dL were gender, age, and mean Elixhauser Comorbidity Index matched against a cohort with a normal serum albumin level. Odds ratios and confidence intervals were calculated for complications at 90 days postoperatively. Mean index and 90-day global reimbursements were calculated for the two matched groups and compared using P-values.3053 protein malnourished patients receiving TJA were identified, and 12,202 matched protein nourished patients receiving TJA served as controls. At 90 days, the malnourished groups had increased risk for failure of multiple organ systems, periprosthetic joint infection, and reoperation. The mean 90-day increase in reimbursement was $3875 associated with performing a TJA on a protein malnourished patient (P < .001).This study demonstrates an association between malnourished patients and postoperative complications as well as significantly increased reimbursements. Understanding the reimbursement increases at 90 days for TJA in protein malnourished patients is important in the era of bundled payments.

  View details for DOI 10.1016/j.arth.2019.11.018

  View details for PubMedID 31879158

• Statin use is associated with less postoperative cardiac arrhythmia after total hip arthroplasty. Hip international : the journal of clinical and experimental research on hip pathology and therapy Chen, M. J., Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Aaronson, A. J., Amanatullah, D. F. 2018: 1120700018816091

  Abstract

  INTRODUCTION:: While statins have been found to reduce postoperative atrial fibrillation after cardiac surgery, little is known about their use in total hip arthroplasty (THA). This study investigated if statins would similarly reduce postoperative arrhythmias in patients undergoing THA.METHODS:: We queried a large Medicare and private-payer database from 2005 to 2012 and identified 12,075 patients who were on a statin prior to THA. We then age and sex matched 34,446 non-statin users who underwent THA. Baseline comorbidities and postoperative complications were obtained and assessed via standard descriptive statistics.RESULTS:: The statin users had more preoperative comorbidities including congestive heart failure, valvular heart disease, pulmonary and renal disease, diabetes, hypertension, obesity, and anaemia (all p values < 0.001). Postoperatively, the statin users had a statistically higher 90-day incidence of transfusion, acute renal failure, heart failure, pneumonia, and sepsis/shock. All new-onset cardiac arrhythmia was significantly less frequent in the statin group at 2weeks (3.88% vs. 4.72%, p < 0.001), 30days (4.47% vs. 5.29%, p < 0.001), and 90days (5.44% vs. 6.31%, p = 0.001) postoperative. There was no difference in the frequency of venous thromboembolism, myocardial infarction, postoperative anaemia, or bleeding at 90days postoperative.DISCUSSION:: Despite being medically sicker at baseline with multiple risk factors for atrial fibrillation compared to the non-statin users, the statin users displayed a consistently lower occurrence of postoperative cardiac arrhythmia in this retrospective cohort study. Statins may therefore be beneficial in the preoperative optimisation of medically complex patients undergoing THA.

  View details for PubMedID 30526117

• Erratum to: Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup. Clinical orthopaedics and related research Zhang, G., Goodman, S. B., Maloney, W. J., Huddleston, J. I. 2018; 476 (12): 2458

  View details for PubMedID 30427315

• Conventional Polyethylene in Total Hip Arthroplasty in Young Patients: Survivorship, Wear Analysis, and Clinical Outcomes Between 15 and 20 Years JOURNAL OF ARTHROPLASTY Stambough, J. B., Rames, R. D., Pashos, G. E., Maloney, W. J., Martell, J. M., Clohisy, J. C. 2018; 33 (12): 3712–18

  Abstract

  Total hip arthroplasty (THA) remains a successful procedure for most patients. However, there is a paucity of information regarding the long-term performance of conventional polyethylene (CPE) bearings in young patients undergoing THA.After accounting for incomplete follow-up of a prospective cohort of 123 THAs in patients ≤50 years, we performed a retrospective review of 101 hips in 84 patients (82.1%) with an average 17.1-year follow-up (14.7-19.6 years). Outcomes of interest included linear and volumetric wear, clinical outcome scores, implant survivorship, and patient mortality. Wear rates were calculated using Martell Software.Wear analysis revealed median linear and volumetric wear rates of 0.106 mm/y (confidence interval, 0.079-0.133) and 43.58 mm3/y (confidence interval, 33.4-53.75). The modified Harris hip scores improved by 36 points while University of California, Los Angeles activity scores improved by 2.0 points at 15-year follow-up (P < .0001). Twenty-two hips (21.8%) were revised, 13 of which (12.8%) were for wear-related causes at an average of 14.9 years (range, 9.2-21 years) from index arthroplasty. There was significantly higher mortality in patients with a preoperative diagnosis of inflammatory avascular necrosis (P = .015).Because CPE was commonly used in THA over the last 25 years, it is important to understand its implications on the growing revision burden. Significant concerns exist with regard to the long-term durability of CPE bearings in young, moderately active patients 15 years after THA. These patients should be followed closely for wear-related problems. Our results should be used as a comparison when evaluating the outcomes of more modern bearing surface combinations.

  View details for PubMedID 30213544

• Suboptimal patellofemoral alignment is associated with poor clinical outcome scores after primary total knee arthroplasty. Archives of orthopaedic and trauma surgery Narkbunnam, R., Electricwala, A. J., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2018

  Abstract

  BACKGROUND: Proper patellofemoral alignment is an important goal in total knee arthroplasty (TKA). Acceptable patellar alignment is defined as patellar tilt less than or equal to 5° and patellar displacement less than or equal to 5mm. Previous studies reported an incidence of post-operative patellar malalignment in TKA from 7 to 35%. However, correlation between patellar malalignment and clinical outcome after TKA remains unclear. The purpose of the present study was to evaluate the effect of patellar tilt and displacement on the clinical outcome of TKA.METHODS: A retrospective review of 138 primary TKAs with a minimum of 2 year follow-up is reported. Pre-operative and post-operative mechanical axis, patellar tilting angle and patellar displacement were measured. Clinical outcomes were evaluated by the knee functional scores including the Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario McMaster University Osteoarthritis Index (WOMAC) at final follow-up.RESULTS: Forty-two (30%) primary TKAs had suboptimal patellofemoral alignment with a patellar tilt angle greater than 5° or lateral patellar displacement of more than 5mm. There was no statistical difference in pre-operative mechanical axis, pre-operative patellar tilt angle, or pre-operative lateral patellar displacement between the primary TKAs with proper patellofemoral alignment and those with suboptimal alignment. Patients with post-operative patellar tilt or displacement had clinically significant reductions in KSS, KOOS, and WOMAC when compared with patients without post-operative patellar tilt or displacement. The odds of having a fair or poor post-operative result, an odds ratio of 3.4 (95% CI 1.6-7.2) for KSS, 6.4 (95% CI 2.9-14.2) for KOOS, and 5.9 (95% CI 2.6-13.5) for WOMAC, were associated with suboptimal patellofemoral alignment.CONCLUSION: Establishing proper patellofemoral alignment remains an essential goal of primary TKA. There is a strong association between suboptimal post-operative patellofemoral alignment and poor clinical outcome scores after primary TKA.

  View details for PubMedID 30483917

• Identifying deer antler uhrf1 proliferation and s100a10 mineralization genes using comparative RNA-seq. Stem cell research & therapy Ker, D. F., Wang, D., Sharma, R., Zhang, B., Passarelli, B., Neff, N., Li, C., Maloney, W., Quake, S., Yang, Y. P. 2018; 9 (1): 292

  Abstract

  BACKGROUND: Deer antlers are bony structures that re-grow at very high rates, making them an attractive model for studying rapid bone regeneration.METHODS: To identify the genes that are involved in this fast pace of bone growth, an in vitro RNA-seq model that paralleled the sharp differences in bone growth between deer antlers and humans was established. Subsequently, RNA-seq (>60 million reads per library) was used to compare transcriptomic profiles. Uniquely expressed deer antler proliferation as well as mineralization genes were identified via a combination of differential gene expression and subtraction analysis. Thereafter, the physiological relevance as well as contributions of these identified genes were determined by immunofluorescence, gene overexpression, and gene knockdown studies.RESULTS: Cell characterization studies showed that in vitro-cultured deer antler-derived reserve mesenchyme (RM) cells exhibited high osteogenic capabilities and cell surface markers similar to in vivo counterparts. Under identical culture conditions, deer antler RM cells proliferated faster (8.6-11.7-fold increase in cell numbers) and exhibited increased osteogenic differentiation (17.4-fold increase in calcium mineralization) compared to human mesenchymal stem cells (hMSCs), paralleling in vivo conditions. Comparative RNA-seq identified 40 and 91 previously unknown and uniquely expressed fallow deer (FD) proliferation and mineralization genes, respectively, including uhrf1 and s100a10. Immunofluorescence studies showed that uhrf1 and s100a10 were expressed in regenerating deer antlers while gene overexpression and gene knockdown studies demonstrated the proliferation contributions of uhrf1 and mineralization capabilities of s100a10.CONCLUSION: Using a simple, in vitro comparative RNA-seq approach, novel genes pertinent to fast bony antler regeneration were identified and their proliferative/osteogenic function was verified via gene overexpression, knockdown, and immunostaining. This combinatorial approach may be applicable to discover unique gene contributions between any two organisms for a given phenomenon-of-interest.

  View details for PubMedID 30376879

• Incidence and Risk Factors for Postoperative Hypothermia After Orthopaedic Surgery. The Journal of the American Academy of Orthopaedic Surgeons Kleimeyer, J. P., Harris, A. H., Sanford, J., Maloney, W. J., Kadry, B., Bishop, J. A. 2018

  Abstract

  INTRODUCTION: Postoperative hypothermia is a common complication of orthopaedic surgery associated with increased morbidity. We identified the incidence and risk factors for postoperative hypothermia across orthopaedic surgical procedures.METHODS: A total of 3,822 procedures were reviewed. Hypothermia was defined as temperature <36.0°C. Incidences were calculated and associated risk factors were evaluated by mixed-effects regression analyses.RESULTS: Hypothermia was observed in 72.5% of patients intraoperatively and 8.3% postoperatively. Risk factors for postoperative hypothermia included intraoperative hypothermia (odds ratio [OR], 2.72), lower preoperative temperature (OR, 1.46), female sex (OR, 1.42), lower body mass index (OR, 1.06 per kg/m), older age (OR, 1.02 per year), adult reconstruction by specialty (OR, 4.06), and hip and pelvis procedures by anatomic region (OR, 8.76).DISCUSSION: Intraoperative and postoperative hypothermia are common in patients who have undergone orthopaedic surgery. The high-risk groups identified in this study warrant increased attention and should be targets for interventions to prevent hypothermia and limit morbidity.LEVEL OF EVIDENCE: Level IV, prognostic study.

  View details for PubMedID 30169443

• Surgery Before Subspecialty Referral for Periprosthetic Knee Infection Reduces the Likelihood of Infection Control. Clinical orthopaedics and related research Song, S. Y., Goodman, S. B., Suh, G., Finlay, A. K., Huddleston, J. I., Maloney, W. J., Amanatullah, D. F. 2018

  Abstract

  BACKGROUND: Failure to control a periprosthetic joint infection (PJI) often leads to referral of the patient to a tertiary care institution. However, there are no data regarding the effect of prior surgical intervention for PJI on subsequent infection control.QUESTIONS/PURPOSES: (1) Is the likelihood of 2-year infection-free survival worse if an initial surgery for PJI was performed before referral to a tertiary care center when compared with after referral for definitive treatment? (2) Is the likelihood of identifying a causal organism during PJI worse if the initial surgery for PJI was performed before referral to a tertiary care center when compared with after referral for definitive treatment? (3) We calculated how many patients are harmed by the practice of surgically attempting to treat PJI before referral to a tertiary care center when compared with treatment after referral to a tertiary care center for definitive treatment.METHODS: Among 179 patients (182 TKAs) who were referred for PJI between 2004 and 2014, we retrospectively studied 160 patients (163 TKAs) who had a minimum of 2 years of followup after surgical treatment or had failure of treatment within 2 years. Nineteen TKAs (19 patients) were excluded from the study; 13 patients (7%) had < 2-year followup, three patients had infected periprosthetic fractures, and three patients had infected extensor mechanism reconstruction. Eighty-six patients (88 TKAs, two bilateral [54%]) had no surgical treatment before referral to our institution for PJI management, and 75 patients (75 TKAs [46%]) had PJI surgery before referral. The mean followup was 2.4 ± 1.2 years for patients with PJI surgery before referral and 2.8 ± 1.3 years for patients with no surgery before referral (p = 0.065). Infection-free survival was defined as prosthesis retention without further surgical intervention or antibiotic suppression. During the period, further surgical intervention generally was performed after failure of irrigation and debridement, a one- or two-stage procedure, or between stages of a two-stage reimplantation without documentation of an eradiated infection, and antibiotic suppression generally was used when patients were not medically sound for surgical intervention or definitive implants were placed after the second of a two-stage procedure with positive cultures; these criteria were applied similarly to all patients during this time period in both study groups. Endpoints were assessed using a longitudinally maintained institutional database, and the treating surgeons were not involved in data abstraction. Relative and absolute risk reductions with 95% confidence intervals (CIs) as well as a Kaplan-Meier survival curve with a Cox proportional hazard model were used to evaluate survival adjusting for significant covariates. The number needed to harm is calculated as the number needed to treat. It is the reciprocal of the absolute risk reduction or production by an intervention.RESULTS: The cumulative infection-free survival rate of TKAs at 2 years or longer was worse when PJI surgery was performed before referral to a tertiary center (80%; 95% CI, 69%-87%) compared with when no PJI surgery was performed before referral (94%; 95% CI, 87%-98%; log-rank test p = 0.006). Additionally, PJI surgery before referral resulted in a lower likelihood of causative microorganism identification (52 of 75 [69%]) compared with patients having surgery at the tertiary center (77 of 88 [88%]; odds ratio, 2.71; 95% CI, 1.28-4.70; p = 0.006). With regard to the infection-free survival rate of TKAs, the number needed to harm was 7.0 (95% CI, 4.1-22.5), meaning the referral of less than seven patients to a tertiary care center for definitive surgical management of PJI before intervention at the referring hospital prevents one infection-related failure. With regard to the culture negativity in PJI, the number needed to harm was 5.5 (95% CI, 3.3-16.7), meaning the referral of less than six patients to a tertiary care institution for PJI before surgery at the outside hospital prevents the diagnosis of one culture-negative infection.CONCLUSIONS: Surgical treatment of a PJI before referral for subspecialty surgical management increases the risk of failure of subsequent surgical management. The prevalence of culture-negative PJI was much higher if surgery was attempted before referral to a tertiary care center when compared with referral before treatment. This suggests that surgical treatment of PJI before referral to a treating center with specialized expertise in PJI compromises the infection-free survival and impacts infecting organism isolation.LEVEL OF EVIDENCE: Level III, therapeutic study.

  View details for PubMedID 30179927

• Proximal Femoral Shape Changes the Risk of a Leg Length Discrepancy After Primary Total Hip Arthroplasty. The Journal of arthroplasty Lim, Y. W., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2018

  Abstract

  BACKGROUND: To evaluate how canal morphology affects the technical aspects of total hip arthroplasty, we investigated the effects of femoral cortical index (FCI) on the re-establishment of leg length at the conclusion of surgery.METHODS: We retrospectively reviewed age, gender, body mass index, and radiographs of 516 patients with osteoarthritis or osteonecrosis who underwent unilateral cementless primary total hip arthroplasty between 2008 and 2015. Patients were divided into level of FCI and leg length discrepancy (LLD). Each cohort was compared in terms of demographics and LLD. One-way analysis of variance and Kruskal-Wallis test were used.RESULTS: The mean FCI and LLD were 0.6 ± 0.1 and 3.5 ± 6.3 mm, respectively. Utilization of an extended offset stem was highest with Dorr type A and B hips (P= .001). High FCI increased the risk of lengthening (P= .017) and low FCI increased the risk of shortening (P= .005).CONCLUSION: A high FCI increases the probability of a leg length increase and a low FCI increases the probability of a leg length decrease. Surgeons might consider informing patients in advance of possible variation in leg length depending on the patients' proximal femoral shape and bony quality.

  View details for PubMedID 30173942

• Systematic characterization of 3D-printed PCL/beta-TCP scaffolds for biomedical devices and bone tissue engineering: Influence of composition and porosity JOURNAL OF MATERIALS RESEARCH Bruyas, A., Lou, F., Stahl, A. M., Gardner, M., Maloney, W., Goodman, S., Yang, Y. 2018; 33 (14): 1948–59

  View details for DOI 10.1557/jmr.2018.112

  View details for Web of Science ID 000440179300003

• Systematic characterization of 3D-printed PCL/β-TCP scaffolds for biomedical devices and bone tissue engineering: influence of composition and porosity. Journal of materials research Bruyas, A., Lou, F., Stahl, A. M., Gardner, M., Maloney, W., Goodman, S., Yang, Y. P. 2018; 33 (14): 1948-1959

  Abstract

  This work aims at providing guidance through systematic experimental characterization, for the design of 3D printed scaffolds for potential orthopaedic applications, focusing on fused deposition modeling (FDM) with a composite of clinically available polycaprolactone (PCL) and β-tricalcium phosphate (β-TCP). First, we studied the effect of the chemical composition (0% to 60% β-TCP/PCL) on the scaffold's properties. We showed that surface roughness and contact angle were respectively proportional and inversely proportional to the amount of β-TCP, and that degradation rate increased with the amount of ceramic. Biologically, the addition of β-TCP enhanced proliferation and osteogenic differentiation of C3H10. Secondly, we systematically investigated the effect of the composition and the porosity on the 3D printed scaffold mechanical properties. Both an increasing amount of β-TCP and a decreasing porosity augmented the apparent Young's modulus of the 3D printed scaffolds. Third, as a proof-of-concept, a novel multi-material biomimetic implant was designed and fabricated for potential disk replacement.

  View details for DOI 10.1557/jmr.2018.112

  View details for PubMedID 30364693

  View details for PubMedCentralID PMC6197810

• Rules of Engagement Using Large Databases: Read the Fine Print JOURNAL OF ARTHROPLASTY Callaghan, J. J., Mont, M. A., Bozic, K., Maloney, W., Berry, D. 2018; 33 (7): 1987

  View details for PubMedID 29891082

• Effect of Computer Navigation on Complication Rates Following Unicompartmental Knee Arthroplasty. The Journal of arthroplasty Chona, D., Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2018

  Abstract

  BACKGROUND: We evaluated whether the complication and revision rates of unicompartmental knee arthroplasty (UKA) performed with intraoperative computer-based navigation differ from standard UKAs performed without intraoperative computer-based navigation.METHODS: A Medicare database containing administrative claims data from 2005 to 2014 was queried. Patients who underwent a single UKA and had a minimum of 2 years of follow-up were included in the study. Data from 1025 UKAs performed with navigation were compared against 9228 age and gender-matched UKAs performed without it. Postoperative complications were identified using International Classification of Diseases, Ninth Revision, codes and evaluated at 30 days, 90 days, and 2 years.RESULTS: Orthopedic complications after UKA are rare, and the use of navigation did not affect the rate of conversion to total knee arthroplasty at 2-year follow-up (3.8% in navigated UKAs vs 4.7% in standard UKAs, P= .218). There were also no significant differences in the rates of knee arthrotomy at 2-year follow-up (1.3% in navigated UKAs vs 1.6% in standard UKAs, P= .379). The rates of deep vein thrombosis at 90-day follow-up did not significantly differ between the 2 groups (1.4% in navigated UKAs vs 2.0% in standard UKAs, P= .157).CONCLUSION: This is one of the first studies to use a large cohort to compare outcomes in computer-assisted surgery-UKA against standard UKAs without navigation. The results, particularly that there was not a difference in the rate of conversion to total knee arthroplasty, are directly relevant to clinical decision-making when surgeons are considering employing navigation during UKA.

  View details for PubMedID 30033063

• Cryptotanshinone Protects Cartilage against Developing Osteoarthritis through the miR-106a-5p/GLIS3 Axis MOLECULAR THERAPY-NUCLEIC ACIDS Ji, Q., Qi, D., Xu, X., Xu, Y., Goodman, S. B., Kang, L., Song, Q., Fan, Z., Maloney, W. J., Wang, Y. 2018; 11: 170–79

  Abstract

  Cryptotanshinone (CTS) has emerged as an anti-inflammatory agent in osteoarthritis (OA). However, the molecular mechanism underlying its potent therapeutic effect on OA remains largely unknown. MicroRNAs (miRNAs) act as crucial regulators in maintaining cartilage homeostasis. To investigate whether CTS protects against developing OA through regulation of miRNAs, we examined the potential CTS-mediated miRNA molecules using microarray analysis. We found that CTS significantly promoted miR-106a-5p expression in chondrocytes. Using the OA mouse model created by anterior cruciate ligament transection, we revealed that intra-articular injection of miR-106a-5p agomir attenuated OA. In addition, miR-106a-5p inhibited GLI-similar 3 (GLIS3) production by directly targeting the 3' untranslated region. CTS promoted miR-106a-5p expression through recruitment of a member of the paired box (PAX) family of transcription factors, PAX5, to the miR-106a-5p promoter. Inhibition of PAX5 mimicked the effect of miR-106a-5p and abolished the CTS ability to regulate miR-106a-5p expression. In OA patients, miR-106-5p is downregulated which is accompanied by downregulation of PAX5 and upregulation of GLIS3. Collectively, these data highlight that the PAX5/miR-106a-5p/GLIS3 axis acts as a novel pleiotropic regulator in CTS-mediated OA cartilage protection, suggesting that miR-106a-5p and PAX5 activation and GLIS3 inhibition might be useful and attractive for therapeutic strategies to treat OA patients.

  View details for PubMedID 29858052

• Protocol-Driven Revision for Stiffness After Total Knee Arthroplasty Improves Motion and Clinical Outcomes. The Journal of arthroplasty Hug, K. T., Amanatullah, D. F., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2018

  Abstract

  BACKGROUND: Stiffness after revision total knee arthroplasty (TKA) is a difficult problem without a well-defined treatment algorithm. The purpose of this study was to evaluate the results of revision TKA for stiffness within the context of differential component replacement.METHODS: Consecutive patients who underwent revision TKA were retrospectively identified and included those who received debridement and polyethylene liner exchange alone, revision of only one of the femoral or tibial fixed components, or revision of all components. Preoperative and postoperative range of motion and Knee Society score (KSS) were collected.RESULTS: Sixty-nine knees were included in the study group with a mean follow-up of 43 months (range, 12-205 months). The mean prerevision flexion contracture of 17° improved to 5° after surgical intervention (P < .001). Similarly, mean flexion and motion arc improved from 70° to 92° and from 53° to 87°, respectively (P < .001). Mean KSS knee scores improved from 42 to 70 and KSS function scores improved from 41 to 68 (P < .001). Mean arc of motion improved by 45° in patients who underwent complete component revision, 32° with component retention, and 29° with single component revision (P= .046). KSS knee scores improved by 34, 25, and 28 points in these respective groups (P= .049). KSS function scores improved by 33, 27, and 25 points (P= .077).CONCLUSION: Revision surgery with or without component revision can improve motion and function in patients with stiffness after TKA. Complete component revision may offer the largest improvements in these outcome measures in properly selected patients.

  View details for DOI 10.1016/j.arth.2018.05.013

  View details for PubMedID 29859726

• miR-223-3p Inhibits Human Osteosarcoma Metastasis and Progression by Directly Targeting CDH6 MOLECULAR THERAPY Ji, Q., Xu, X., Song, Q., Xu, Y., Tai, Y., Goodman, S. B., Bi, W., Xu, M., Jiao, S., Maloney, W. J., Wang, Y. 2018; 26 (5): 1299–1312

  Abstract

  Cadherin-6 (CDH6) is aberrantly expressed in cancer and closely associated with tumor progression. However, the functions of CDH6 in human osteosarcoma and the molecular mechanisms underlying CDH6 in osteosarcoma oncogenesis remain poorly understood. In this work, we assessed the role of CDH6 in human osteosarcoma and identified that the expression of CDH6 was closely related with the overall survival and poor prognosis of osteosarcoma patients. MicroRNAs (miRNAs) have been implicated as important epigenetic regulators during the progression of osteosarcoma. Using dual-luciferase reporter assays, we showed that miR-223-3p suppresses CDH6 expression by directly binding to the 3' UTR of CDH6. miR-223-3p overexpression significantly inhibited cell invasion, migration, growth, and proliferation by suppressing the CDH6 expression in vivo and in vitro. Besides, CDH6 overexpression in the miR-223-3p-transfected osteosarcoma cells effectively rescued the inhibition of cell invasion, migration, growth, and proliferation mediated by miR-223-3p. Additionally, Kaplan-Meier analysis suggests that the expression of miR-223-3p predicts favorable clinical outcomes for osteosarcoma patients. Moreover, the expression of miR-223-3p was downregulated in osteosarcoma patients and was negatively associated with the expression of CDH6. Collectively, these data highlight that miR-223-3p/CDH6 axis is an important novel pleiotropic regulator and could early predict the metastatic potential in human osteosarcoma treatments.

  View details for PubMedID 29628305

• Obesity Is Independently Associated With Early Aseptic Loosening in Primary Total Hip Arthroplasty JOURNAL OF ARTHROPLASTY Goodnough, L. H., Finlay, A. K., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2018; 33 (3): 882–86

  Abstract

  Obesity affects millions of patients in the United States and is associated with several complications after total hip arthroplasty (THA). The effect of obesity on the rate and mode of primary THA failure remains poorly understood, especially given other potentially confounding patient characteristics. We hypothesized that, among patients with a failed primary THA, obesity is independently associated with aseptic loosening and a higher rate of early revision.Six hundred eighty-four consecutive cases with failed THA referred to a single academic center for revision during a 10-year period were retrospectively reviewed. Multivariate logistic regression analysis was used to test the independent association between obesity and the timing as well as cause of THA failure.The rate of primary THA failure before 5 years was 48.8% in obese and 37.1% in nonobese patients (odds ratio [OR] = 1.57, P = .010). Primary THA failure before 5 years was more likely with increasing body mass index (BMI) (BMI: 35-40 kg/m2, OR = 2.31, P = .008; BMI >40 kg/m2, OR = 2.51, P = .049). The rate of primary THA failure for aseptic loosening before 5 years was 30% in obese and 18% in nonobese patients (OR = 1.88, P = .023). Obesity was not a risk for revision for infection, whereas an American Society of Anesthesiologists class ≥3 was independently associated with primary THA failure for infection (OR = 2.33, P < .001).Among patients with a failed THA, comorbidities may account for the risk of revision due to infection in obese patients. Obesity is independently associated with early primary THA failure for aseptic loosening.

  View details for DOI 10.1016/j.arth.2017.09.069

  View details for Web of Science ID 000425893000046

  View details for PubMedID 29089226

• Metal-on-metal total hip arthroplasty is not associated with cardiac disease BONE & JOINT JOURNAL Goodnough, L. H., Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2018; 100B (1): 28–32

  Abstract

  Many case reports and small studies have suggested that cobalt ions are a potential cause of cardiac complications, specifically cardiomyopathy, after metal-on-metal (MoM) total hip arthroplasty (THA). The impact of metal ions on the incidence of cardiac disease after MoM THA has not been evaluated in large studies. The aim of this study was to compare the rate of onset of new cardiac symptoms in patients who have undergone MoM THA with those who have undergone metal-on-polyethylene (MoP) THA.Data were extracted from the Standard Analytics Files database for patients who underwent MoM THA between 2005 and 2012. Bearing surface was selected using International Classification of Diseases ninth revision codes. Patients with a minimum five-year follow-up were selected. An age and gender-matched cohort of patients who underwent MoP THA served as a comparison group. New diagnoses of cardiac disease were collected during the follow-up period. Comorbidities and demographics were identified and routine descriptive statistics were used.We identified 29 483 patients who underwent MoM THA and 24 175 matched patients who underwent MoP THA. Both groups had a mean Charlson comorbidity index score of 4. There were no statistically significant differences in 30 of 31 pre-existing comorbidities. Patients undergoing MoM THA had a slightly lower incidence of cardiac failure compared with those undergoing MoP THA at three years (6.60% versus 7.06%, odds ratio (OR) 0.93, 95% confidence interval (CI) 0.87 to 0.99) and four years (8.73% versus 9.49%, OR 0.91, 95% CI 0.86 to 0.97) postoperatively, with no difference in the incidence of new cardiac failure in between the groups at five years. There was no statistically significant difference in the incidence of arrhythmia, myocardial infarction and cardiomyopathy at any time between the two groups.MoM THA is not associated with cardiac complications. Initial reports may have represented individual instances of cardiac disease in patients with a failing MoM articulation rather than an emerging epidemiological trend. Cite this article: Bone Joint J 2018;100-B:28-32.

  View details for PubMedID 29305447

• Corrigendum to Outcome of 4 Surgical Treatments for Wear and Osteolysis of Cementless Acetabular Components [The Journal of Arthroplasty 32 (2017) 2799-2805]. The Journal of arthroplasty Narkbunnam, R., Amanatullah, D. F., Electricwala, A. J., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2018; 33 (1): 308

  View details for DOI 10.1016/j.arth.2017.10.001

  View details for PubMedID 29107500

• Outcome of 4 Surgical Treatments for Wear and Osteolysis of Cementless Acetabular Components (vol 32, pg 2799, 2017) JOURNAL OF ARTHROPLASTY Narkbunnam, R., Amanatullah, D. F., Electricwala, A. J., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2018; 33 (1): 308

  View details for DOI 10.1016/j.arth.2017.10.001

  View details for Web of Science ID 000418761100061

• miR-216a inhibits osteosarcoma cell proliferation, invasion and metastasis by targeting CDK14 CELL DEATH & DISEASE Ji, Q., Xu, X., Li, L., Goodman, S. B., Bi, W., Xu, M., Xu, Y., Fan, Z., Maloney, W. J., Ye, Q., Wang, Y. 2017; 8: e3103

  Abstract

  Osteosarcoma (OS) has emerged as the most common primary musculoskeletal malignant tumour affecting children and young adults. Cyclin-dependent kinases (CDKs) are closely associated with gene regulation in tumour biology. Accumulating evidence indicates that the aberrant function of CDK14 is involved in a broad spectrum of diseases and is associated with clinical outcomes. MicroRNAs (miRNAs) are crucial epigenetic regulators in the development of OS. However, the essential role of CDK14 and the molecular mechanisms by which miRNAs regulate CDK14 in the oncogenesis and progression of OS have not been fully elucidated. Here we found that CDK14 expression was closely associated with poor prognosis and overall survival of OS patients. Using dual-luciferase reporter assays, we also found that miR-216a inhibits CDK14 expression by binding to the 3'-untranslated region of CDK14. Overexpression of miR-216a significantly suppressed cell proliferation, migration and invasion in vivo and in vitro by inhibiting CDK14 production. Overexpression of CDK14 in the miR-216a-transfected OS cells effectively rescued the suppression of cell proliferation, migration and invasion caused by miR-216a. In addition, Kaplan-Meier analysis indicated that miR-216a expression predicted favourable clinical outcomes for OS patients. Moreover, miR-216a expression was downregulated in OS patients and was negatively associated with CDK14 expression. Overall, these data highlight the role of the miR-216a/CDK14 axis as a novel pleiotropic modulator and demonstrate the associated molecular mechanisms, thus suggesting the intriguing possibility that miR-216a activation and CDK14 inhibition may be novel and attractive therapeutic strategies for treating OS patients.

  View details for PubMedID 29022909

• Response to Letter to the Editor on "Weight Gain After Primary Total Knee Arthroplasty is Associated With Accelerated Time to Revision for Aseptic Loosening" JOURNAL OF ARTHROPLASTY Lim, C. T., Goodman, S. B., Huddleston, J. I., Harris, A. S., Bhowmick, S., Maloney, W. J., Amanatullah, D. F. 2017; 32 (10): 3258

  View details for PubMedID 28705544

• Long-term Intra-articular Steroid Injections and Knee Cartilage JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Maloney, W. J., Jevsevar, D. S., Shea, K. G. 2017; 318 (12): 1184–85

  View details for PubMedID 28973607

• Continuous Femoral Nerve Catheters Decrease Opioid-Related Side Effects and Increase Home Disposition Rates Among Geriatric Hip Fracture Patients. Journal of orthopaedic trauma Arsoy, D., Gardner, M. J., Amanatullah, D. F., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Bishop, J. A. 2017; 31 (6): e186-e189

  Abstract

  To evaluate the effect of continuous femoral nerve catheter (CFNC) for postoperative pain control in geriatric proximal femur fractures compared with standard analgesia (SA) treatment.Retrospective comparative study.Academic Level 1 trauma center.We retrospectively identified 265 consecutive geriatric hip fracture patients who underwent surgical treatment.One hundred forty-nine patients were treated with standard analgesia without nerve catheter whereas 116 patients received an indwelling CFNC.Daily average preoperative and postoperative pain scores, daily morphine equivalent consumption, opioid-related side effects and discharge disposition.Patients with CFNC patients reported lower average pain scores preoperatively (1.9 ± 1.7 for CFNC vs. 4.7 ± 2 for SA; P < 0.0001), on postoperative day 1 (1.5 ± 1.6 for CFNC vs. 3 ± 1.7 for SA; P < 0.0001) and postoperative day 2 (1.2 ± 1.5 for CFNC vs. 2.6 ± 2.1 for SA; P < 0.0001). CFNC group consumed 39% less morphine equivalents on postoperative day 1 (4.4 ± 5.8 mg for CFNC vs. 7.2 ± 10.8 mg for SA; P = 0.005) and 50% less morphine equivalent on postoperative day 2 (3.4 ± 4.4 mg for CFNC vs. 6.8 ± 13 mg for SA; P = 0.105). Patients with CFNC had a lower rate of opioid-related side effects compared with patients with SA (27.5% for CFNC vs. 47% for SA; P = 0.001). More patients with CFNC were discharged to home with or without health services than patients with SA (15% for CFNC vs. 6% for SA; P = 0.023).Continuous femoral nerve catheter decreased daily average patient-reported pain scores, narcotic consumption while decreasing the rate of opioid-related side effects. Patients with CFNC were discharged to home more frequently.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  View details for DOI 10.1097/BOT.0000000000000854

  View details for PubMedID 28538458

• The effect of desflurane versus propofol anesthesia on postoperative delirium in elderly obese patients undergoing total knee replacement: A randomized, controlled, double-blinded clinical trial. Journal of clinical anesthesia Tanaka, P., Goodman, S., Sommer, B. R., Maloney, W., Huddleston, J., Lemmens, H. J. 2017; 39: 17-22

  Abstract

  The goal of this study was to investigate the incidence of delirium, wake-up times and early post-operative cognitive decline in one hundred obese elderly patients undergoing total knee arthroplasty.Prospective randomized trial.Operating room, postoperative recovery area, hospital wards.100 obese patients (ASA II and III) undergoing primary total knee replacement under general anesthesia with a femoral nerve block catheter.Patients were prospectively randomized to maintenance anesthesia with either propofol or desflurane.The primary endpoint assessed by a blinded investigator was delirium as measured by the Confusion Assessment Method. Secondary endpoints were wake-up times and a battery of six different tests of cognitive function.Four of the 100 patients that gave informed consent withdrew from the study. Of the remaining 96 patients, 6 patients did not complete full CAM testing. Preoperative pain scores, durations of surgery and anesthesia, and amount of intraoperative fentanyl were not different between groups. One patient in the propofol group developed delirium compared to zero in desflurane. One patient in desflurane group developed a confused state not characterized as delirium. Fifty percent of the patients exhibited a 20% decrease in the results of at least one cognitive test on the first 2days after surgery, with no difference between groups. There were no differences in the time to emergence from anesthesia, incidence of postoperative nausea and vomiting, and length of postanesthesia care unit (PACU) stay between the two groups.In conclusion we found a low incidence of delirium but significant cognitive decline in the first 48h after surgery. In this relatively small sample size of a hundred patients there was no difference in the incidence of postoperative delirium, early cognitive outcomes, or wake up times between the desflurane or propofol group.

  View details for DOI 10.1016/j.jclinane.2017.03.015

  View details for PubMedID 28494898

• Venous Thromboembolism Prophylaxis After TKA: Aspirin, Warfarin, Enoxaparin, or Factor Xa Inhibitors? Clinical orthopaedics and related research Bala, A., Huddleston, J. I., Goodman, S. B., Maloney, W. J., Amanatullah, D. F. 2017

  Abstract

  There is considerable debate regarding the ideal agent for venous thromboembolism (VTE) prophylaxis after TKA. Numerous studies and meta-analyses have yet to provide a clear answer and often omit one or more of the commonly used agents such as aspirin, warfarin, enoxaparin, and factor Xa inhibitors.Using a large database analysis, we asked: (1) What are the differences in VTE incidence in primary TKA after administration of aspirin, warfarin, enoxaparin, or factor Xa inhibitors? (2) What are the differences in bleeding risk among these four agents? (3) How has use of these agents changed with time?We queried a combined Humana and Medicare database between 2007 and Quarter 1 of 2016, and identified all primary TKAs performed using ICD-9 and Current Procedural Terminology codes. All patients who had any form of antiplatelet or anticoagulation prescribed within 1 year before TKA were excluded from our study cohort. We then identified patients who had either aspirin, warfarin, enoxaparin, or factor Xa inhibitors prescribed within 2 weeks of primary TKA. Each cohort was matched by age and sex. Elixhauser comorbidities and Charlson Comorbidity Index for each group were calculated. We identified 1016 patients with aspirin, and age- and sex-matched 6096 patients with enoxaparin, 6096 patients with warfarin, and 5080 patients with factor Xa inhibitors. Using ICD-9 codes, with the understanding that patients at greater risk may have had more-attentive surveillance, the incidence of postoperative deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding-related complications (bleeding requiring surgical intervention, hemorrhage, hematoma, hemarthrosis), postoperative anemia, and transfusion were identified at 2 weeks, 30 days, 6 weeks, and 90 days postoperatively. A four-way chi-squared test was used to determine statistical significance. Utilization was calculated using compound annual growth rate.There was a difference in the incidence of DVT at 90 days (p < 0.01). Factor Xa inhibitors (2.9%) had the lowest incidence of DVT followed by aspirin (3.0%) and enoxaparin (3.5%), and warfarin (4.8%). There was a difference in the incidence of PE at 90 days (p < 0.01). Factor Xa inhibitors (0.9%) had the lowest incidence of PE followed by enoxaparin (1.1%), aspirin (1.2%), and warfarin (1.6%). There was a difference in the incidence of postoperative anemia at 90 days (p < 0.01). Aspirin (19%) had the lowest incidence of postoperative anemia followed by warfarin (22%), enoxaparin (23%), and factor Xa inhibitors (23%). There was a difference in the incidence of a blood transfusion at 90 days (p < 0.01). Aspirin (7%) had the lowest incidence of a blood transfusion followed by factor Xa inhibitors (9%), warfarin (12%), and enoxaparin (13%). There were no differences in bleeding-related complications (p = 0.81) between the groups. Aspirin use increased at a compound annual growth rate of 30%, enoxaparin at 3%, and factor Xa inhibitors at 43%, while warfarin use decreased at a compound annual growth rate of -3%.Factor Xa inhibitors had the highest growth in utilization during our study period, followed by aspirin, when compared with enoxaparin and warfarin. When selected for the right patient, factor Xa inhibitors provided improved VTE prophylaxis compared with enoxaparin and warfarin, with a lower rate of blood transfusion. Aspirin provided comparable VTE prophylaxis compared with factor Xa inhibitors with improved VTE prophylaxis compared with enoxaparin and warfarin with the lowest risk of bleeding.Level III, therapeutic study.

  View details for DOI 10.1007/s11999-017-5394-6

  View details for PubMedID 28569372

• Radiographic scoring system for the evaluation of stability of cementless acetabular components in the presence of osteolysis BONE & JOINT JOURNAL Narkbunnam, R., Amanatullah, D. F., Electricwala, A. J., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2017; 99-B (5): 601-606

  Abstract

  The stability of cementless acetabular components is an important factor for surgical planning in the treatment of patients with pelvic osteolysis after total hip arthroplasty (THA). However, the methods for determining the stability of the acetabular component from pre-operative radiographs remain controversial. Our aim was to develop a scoring system to help in the assessment of the stability of the acetabular component under these circumstances.The new scoring system is based on the mechanism of failure of these components and the location of the osteolytic lesion, according to the DeLee and Charnley classification. Each zone is evaluated and scored separately. The sum of the individual scores from the three zones is reported as a total score with a maximum of 10 points. The study involved 96 revision procedures which were undertaken for wear or osteolysis in 91 patients between July 2002 and December 2012. Pre-operative anteroposterior pelvic radiographs and Judet views were reviewed. The stability of the acetabular component was confirmed intra-operatively.Intra-operatively, it was found that 64 components were well-fixed and 32 were loose. Mean total scores in the well-fixed and loose components were 2.9 (0 to 7) and 7.2 (1 to 10), respectively (p < 0.001). In hips with a low score (0 to 2), the component was only loose in one of 33 hips (3%). The incidence of loosening increased with increasing scores: in those with scores of 3 and 4, two of 19 components (10.5%) were loose; in hips with scores of 5 and 6, eight of 19 components (44.5%) were loose; in hips with scores of 7 or 8, 13 of 17 components (70.6%) were loose; and for hips with scores of 9 and 10, nine of nine components (100%) were loose. Receiver-operating-characteristic curve analysis demonstrated very good accuracy (area under the curve = 0.90, p < 0.001). The optimal cutoff point was a score of ≥ 5 with a sensitivity of 0.79, and a specificity of 0.87.There was a strong correlation between the scoring system and the probability of loosening of a cementless acetabular component. This scoring system provides a clinically useful tool for pre-operative planning, and the evaluation of the outcome of revision surgery for patients with loosening of a cementless acetabular component in the presence of osteolysis. Cite this article: Bone Joint J 2017;99-B:601-6.

  View details for DOI 10.1302/0301-620X.99B5.BJJ-2016-0968.R1

  View details for PubMedID 28455468

• Cortical Strut Allograft Support of Modular Femoral Junctions During Revision Total Hip Arthroplasty JOURNAL OF ARTHROPLASTY Lim, C. T., Amanatullah, D. F., Huddleston, J. I., Hwang, K. L., Maloney, W. J., Goodman, S. B. 2017; 32 (5): 1586-1592

  Abstract

  There is risk of junction failure when using modular femoral stems for revision total hip arthroplasty (THA), especially with loss of bone stock in the proximal femur. Using a cortical strut allograft may provide additional support of a modular femoral construct in revision THA.We reviewed prospectively gathered clinical and radiographic data for 28 revision THAs performed from 2004 to 2014 using cementless modular femoral components with cortical strut allograft applied to supplement proximal femoral bone loss: 5 (18%) were fluted taper designs and 23 (82%) were porous cylindrical designs All the patients had a Paprosky grade IIIA or greater femoral defect. The mean follow-up was 5.4 ± 3.9 years.The Harris Hip Scores improved from 26 ± 10 points preoperatively to 71 ± 10 points at final follow-up (P < .001). The Western Ontario McMaster Universities Osteoarthritis Index scores improved from 45 ± 12 points preoperatively to 76 ± 12 points at final follow-up (P < .001). Eighty-nine percent (25 hips) of all revision or conversion THAs were in place at final follow-up. Three (11%) patients underwent reoperations, 2 for infection and 1 for periprosthetic fracture. There was no statistical significant change in femoral component alignment (P = .161) at final follow-up. Mean subsidence was 1.8 ± 1.3 mm at final follow-up. Femoral diameter increased from initial postoperative imaging to final follow-up imaging by a mean of 9.1 ± 5.1 mm (P < .001) and cortical width increased by a mean of 4.5 ± 2.2 mm (P < .001). Twenty-seven hips (96%) achieved union between the cortical strut allograft and the host femur.The use of a modular femoral stem in a compromised femur with a supplementary cortical strut allgraft is safe and provides satisfactory clinical and radiological outcomes.

  View details for DOI 10.1016/j.arth.2016.12.011

  View details for Web of Science ID 000401132100033

• Use of Cortical Strut Allograft After Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty JOURNAL OF ARTHROPLASTY Lim, C. T., Amanatullah, D. F., Huddleston, J. I., Hwang, K. L., Maloney, W. J., Goodman, S. B. 2017; 32 (5): 1599-1605

  Abstract

  Cortical strut allografts restore bone stock and improve postoperative clinical scores after revision total hip arthroplasty (THA). However, use of a cortical strut allograft is implicated in delayed healing of an extended trochanteric osteotomy (ETO). To date, there are no reports directly comparing ETO with or without cortical strut allografts.We reviewed prospectively gathered data on 50 revision THAs performed from 2004-2014 using an ETO. We compared the demographic, radiological, and clinical outcome of patients with (16 hips) and without (34 hips) cortical strut allograft after an ETO.There were no significant differences in Western Ontario McMaster Universities Osteoarthritis Index or Harris Hip Score between the ETOs with and without a cortical strut allograft. Fifteen of the ETOs (94%) with a cortical strut allograft and 31 of the ETOs (91%) without a cortical strut allograft were in situ at final follow-up (P = 1.000). A higher proportion hips with cortical strut allograft (100%, 16 patients) had preoperative Paprosky grade bone loss more than IIIA compared to those without allograft (29%, 10 patients) (P < .001). There were no differences in femoral stem subsidence (P = .207), alignment (P = .934), or migration of the osteotomized fragment (P = .171). Fourteen of the ETOs (88%) in patients with cortical strut allograft united compared to 34 ETOs (100%) in patients without allograft (P = .095).Our study shows that the use of cortical strut allograft during revision THA with ETO does not reduce the rate of union, radiological or clinical outcomes.

  View details for DOI 10.1016/j.arth.2016.12.002

  View details for Web of Science ID 000401132100035

• Outcome of 4 Surgical Treatments for Wear and Osteolysis of Cementless Acetabular Components. journal of arthroplasty Narkbunnam, R., Amanatullah, D. F., Electriwala, A. J., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2017

  Abstract

  Loosening and periprosthetic osteolysis are some of the most common long-term complications after hip arthroplasty. The decision-making process and surgical treatment options are controversial.We retrospectively reviewed 96 acetabular revisions (91 patients) performed between 2002 and 2012, with a minimum of 2 years of follow-up and a mean of 5.7 years of follow-up. Clinical outcome was assessed using the Harris Hip Score. The size and location of osteolytic lesions were evaluated using the preoperative radiographs; healing of the defects was categorized using a standardized protocol.Thirty-three (34.4%) hips had isolated liner exchanges (ILEs), 10 (10.4%) hips had cemented liners into well-fixed shells (CLS), 45 (46.9%) hips had full acetabular revisions (FARs), and 8 (8.3%) hips had revision with a roof ring/antiprotrusio cage (RWC). All procedures showed significant improvement in Harris Hip Score after revision (P ≤ .001). Fifteen patients had moderate residual pain (pain score ≤20): 8 (24%) ILE, 3 (30%) CLS, and 4 (9%) FAR. Complete bone defect healing after grafting was lower with acetabular component retention procedures (ILE and CLS; 27%) compared with full acetabular component revision procedures (FAR and RWC; 57%). Fifteen patients underwent reoperation: 3 ILE, 1 CLS, 8 FAR, and 3 RWC.Acetabular component retention demonstrates a low risk of reoperation; however, residual pain and limited potential for bone graft incorporation are a concern. FAR is technically challenging and may have an elevated risk of reoperation; however, higher degrees of bone graft incorporation and satisfactory clinical outcome can be expected.

  View details for DOI 10.1016/j.arth.2017.04.028

  View details for PubMedID 28587888

• The Direct Anterior Approach is Associated With Early Revision Total Hip Arthroplasty. journal of arthroplasty Eto, S., Hwang, K., Huddleston, J. I., Amanatullah, D. F., Maloney, W. J., Goodman, S. B. 2017; 32 (3): 1001-1005

  Abstract

  The direct anterior approach for total hip arthroplasty (THA) has generated increased interest recently. The purpose of this study was to compare the duration to failure and reasons for revision of primary THA performed elsewhere and subsequently revised at our institution after the direct anterior vs other nonanterior surgical approaches to the hip.All primary THAs performed elsewhere and referred to our institution for revision were divided into the direct anterior approach (30 cases) or nonanterior approach groups (100 cases, randomly selected from 453 cases) based on the original surgical approach. Because all primary direct anterior THAs were originally performed after 2004 to eliminate temporal bias, we identified a subset of the nonanterior group in which the primary THA was performed after 2004 (known as the recent nonanterior group, 100 cases, randomly selected from 169 available cases).The mean duration from primary to revision THA was 3.0 ± 2.7 years (direct anterior approach), 12.0 ± 8.8 years (nonanterior approach), and 3.6 ± 2.8 years (recent nonanterior), respectively. There was a significant difference in time to revision between the direct anterior and nonanterior approach groups (P < .001). Aseptic loosening of the stem was significantly more frequent with the direct anterior approach group (9/30, 30.0%) when compared with the nonanterior group (8/100, 8.0%, P = .007) and the recent nonanterior group (7/100, 7.0%, P = .002).Revision of the femoral component for aseptic loosening is more commonly associated with the direct anterior approach in our referral practice.

  View details for DOI 10.1016/j.arth.2016.09.012

  View details for PubMedID 27843039

• Weight Gain After Primary Total Knee Arthroplasty Is Associated With Accelerated Time to Revision for Aseptic Loosening. journal of arthroplasty Lim, C. T., Goodman, S. B., Huddleston, J. I., Harris, A. H., Bhowmick, S., Maloney, W. J., Amanatullah, D. F. 2017

  Abstract

  Obesity is a major health problem worldwide and is associated with complications after total knee arthroplasty (TKA). It remains unknown whether a change in body mass index (BMI) after primary TKA affects the reasons for revision TKA or the time to revision TKA.A total of 160 primary TKAs referred to an academic tertiary center for revision TKA were retrospectively stratified according to change in BMI from the time of their primary TKA to revision TKA. The association between change in BMI and time to revision was also analyzed according to indication for revision of TKA using Pearson's chi-square test.The mean change in BMI from primary to revision TKA was 0.82 ± 3.5 kg/m(2). Maintaining a stable weight after primary TKA was protective against late revision TKA for any reason (P = .004). Patients who failed to reduce their BMI were revised for aseptic loosening earlier, at less than 5 years (P = .020), whereas those who reduced their BMI were revised later, at over 10 years (P = .004).Maintaining weight after primary TKA is protective against later revision TKA for any reason but failure to reduce weight after primary TKA is a risk factor for early revision TKA for aseptic loosening and osteolysis. Orthopedic surgeons should recommend against weight gain after primary TKA to reduce the risk of an earlier revision TKA in the event that a revision TKA is indicated.

  View details for DOI 10.1016/j.arth.2017.02.026

  View details for PubMedID 28318864

• Response to Letter to the Editor on 'Tibiofemoral Dislocation After Total Knee Arthroplasty' JOURNAL OF ARTHROPLASTY Jethanandani, R. G., Maloney, W. J., Huddleston, J. I., Goodman, S. B., Amanatullah, D. F. 2017; 32 (2): 700-700

  View details for DOI 10.1016/j.arth.2016.10.021

  View details for PubMedID 27865569

• Elevated Body Mass Index Is Associated With Early Total Knee Revision for Infection JOURNAL OF ARTHROPLASTY Electricwala, A. J., Jethanandani, R. G., Narkbunnam, R., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2017; 32 (1): 252-255

  Abstract

  Obesity affects over half a billion people worldwide, including one-third of men and women in the United States. Obesity is associated with higher postoperative complication rates after total knee arthroplasty (TKA). It remains unknown whether obese patients progress to revision TKA faster than nonobese patients.A total of 666 consecutive primary TKAs referred to an academic tertiary care center for revision TKA were retrospectively stratified according to body mass index (BMI), reason for revision TKA, and time from primary to revision TKA.When examining primary TKAs referred for revision TKA, increasing BMI adversely affected the mean time to revision TKA. The percent of referred TKAs revised by 5 years was 54% for a normal BMI, 64% for an overweight patient, 71% for an obese class I patient, 68% for an obese class II patient, and 73% for a morbidly obese patient. There was a significant difference in time to revision TKA between patients with normal BMI and elevated BMI (P = .005). There was a significant increase in early revision TKA for infection in patients with an elevated BMI (54%, 74/138) when compared with the normal BMI patients (24%, 8/33, P < .003, relative risk ratio = 2.3, absolute risk = 30%, number needed to treat = 3.3). There was no significant increase in acute, early, midterm, or late revision TKA for aseptic loosening and/or osteolysis, instability, stiffness, or other causes between patients with normal BMI and elevated BMI.An elevated BMI is a risk factor for early referral to a tertiary care center for revision TKA. Specifically, orthopedic surgeons should convey to overweight and obese patients that they have at least a 130% increased relative risk and a 30% absolute risk of revision TKA for an early infection if referred for revision TKA. Patient expectations and counseling as well as reimbursement should account for the greater risks when performing a TKA on patients with an elevated BMI.

  View details for DOI 10.1016/j.arth.2016.05.071

  View details for PubMedID 27421585

• Smoking is associated with earlier time to revision of total knee arthroplasty. The Knee Lim, C. T., Goodman, S. B., Huddleston, J. I., Harris, A. H., Bhowmick, S. n., Maloney, W. J., Amanatullah, D. F. 2017

  Abstract

  Smoking is associated with early postoperative complications, increased length of hospital stay, and an increased risk of revision after total knee arthroplasty (TKA). However, the effect of smoking on time to revision TKA is unknown.A total of 619 primary TKAs referred to an academic tertiary center for revision TKA were retrospectively stratified according to the patient smoking status. Smoking status was then analyzed for associations with time to revision TKA using a Chi square test. The association was also analyzed according to the indication for revision TKA.Smokers (37/41, 90%) have an increased risk of earlier revision for any reason compared to non-smokers (274/357, 77%, p=0.031). Smokers (37/41, 90%) have an increased risk of earlier revision for any reason compared to ex-smokers (168/221, 76%, p=0.028). Subgroup analysis did not reveal a difference in indication for revision TKA (p>0.05).Smokers are at increased risk of earlier revision TKA when compared to non-smokers and ex-smokers. The risk for ex-smokers was similar to that of non-smokers. Smoking appears to have an all-or-none effect on earlier revision TKA as patients who smoked more did not have higher risk of early revision TKA. These results highlight the need for clinicians to urge patients not to begin smoking and encourage smokers to quit smoking prior to primary TKA.

  View details for PubMedID 28797880

• Reconstruction of Disrupted Extensor Mechanism After Total Knee Arthroplasty. The Journal of arthroplasty Lim, C. T., Amanatullah, D. F., Huddleston, J. I., Harris, A. H., Hwang, K. L., Maloney, W. J., Goodman, S. B. 2017

  Abstract

  Disruption of the extensor mechanism after total knee arthroplasty (TKA) is a debilitating complication that results in extension lag, limited range of motion, difficulty in walking, frequent falls, and chronic pain. This study presents the clinical and radiographic results of reconstruction after extensor mechanism disruption in TKA patients.Consecutive patients with allograft reconstruction of extensor mechanism after TKA were identified retrospectively from an academic tertiary center for revision TKA.Sixteen patients with a mean age of 61 ± 14 years at extensor mechanism reconstruction with a minimum of 2-year follow-up were included. The mean follow-up was 3.3 ± 2.2 years. Knee Society score (KSS), before and at final follow-up extension lag, range of motion, and radiographic change in patellar height were reviewed. There were statistically significant improvements between preoperative and final follow-up KSS (P < .001; KSS for pain, preoperative 40 ± 14 points to final follow-up 67 ± 15 points [P < .001]; KSS for function, preoperative 26 ± 21 points to final follow-up 48 ± 25 points [P < .001]). The extension lag was also reduced from 35° ± 16° preoperatively to 14° ± 18° (P < .001) at final follow-up. There was an average proximal patellar migration of 8 ± 10 mm. Five (31%) cases had an extensor lag of >30° or revision surgery for repeat extensor mechanism reconstruction, infection, or arthrodesis.Our 10-year experience using allografts during extensor mechanism reconstruction demonstrates reasonable outcomes, but failures are to be anticipated in approximately one-third of patients.

  View details for PubMedID 28634096

• Femoral Nerve Catheters Improve Home Disposition and Pain in Hip Fracture Patients Treated With Total Hip Arthroplasty. The Journal of arthroplasty Arsoy, D. n., Huddleston, J. I., Amanatullah, D. F., Giori, N. J., Maloney, W. J., Goodman, S. B. 2017

  Abstract

  Opioids have been the mainstay of treatment in the physiologically young geriatric hip fracture patient undergoing total hip arthroplasty (THA). However opioid-related side effects increase morbidity. Regional anesthesia may provide better analgesia, while decreasing opioid-related side effects. The goal of this study was to examine the effect of perioperative continuous femoral nerve blockade with regards to pain scores, opioid-related side effects and posthospital disposition in hip fracture patients undergoing THA.Twenty-nine consecutive geriatric hip fracture patients (22 women/7 men) underwent THA. Average follow-up was 8.3 months (6 weeks-39 months). Fifteen patients were treated with standard analgesia (SA). Fourteen patients received an ultrasound-guided insertion of a femoral nerve catheter after radiographic confirmation of a hip fracture. All complications and readmissions that occurred within 6 weeks of surgery were noted.Continuous femoral nerve catheter (CFNC) patients were discharged home more frequently than SA patients (43% for CFNC vs 7% for SA; P = .023). CFNC patients reported lower average pain scores preoperatively (P < .0001), on postoperative day 1 (P = .005) and postoperative day 2 (P = .037). Preoperatively, CFNC patients required 61% less morphine equivalent (P = .007). CFNC patients had a lower rate of opioid-related side effects compared with SA patients (7% vs 47%; P = .035).CFNC patients were discharged to home more frequently. Use of a CFNC decreased daily average patient-reported pain scores, preoperative opioid usage, and opioid-related side effects after THA for hip fracture. Based on these data, we recommend routine use of perioperative CFNC in hip fracture patients undergoing THA.

  View details for PubMedID 28641968

• Effect of Perioperative Gabapentin on Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: A Randomized Clinical Trial. JAMA surgery Hah, J. n., Mackey, S. C., Schmidt, P. n., McCue, R. n., Humphreys, K. n., Trafton, J. n., Efron, B. n., Clay, D. n., Sharifzadeh, Y. n., Ruchelli, G. n., Goodman, S. n., Huddleston, J. n., Maloney, W. J., Dirbas, F. M., Shrager, J. n., Costouros, J. n., Curtin, C. n., Carroll, I. n. 2017

  Abstract

  Guidelines recommend using gabapentin to decrease postoperative pain and opioid use, but significant variation exists in clinical practice.To determine the effect of perioperative gabapentin on remote postoperative time to pain resolution and opioid cessation.A randomized, double-blind, placebo-controlled trial of perioperative gabapentin was conducted at a single-center, tertiary referral teaching hospital. A total of 1805 patients aged 18 to 75 years scheduled for surgery (thoracotomy, video-assisted thoracoscopic surgery, total hip replacement, total knee replacement, mastectomy, breast lumpectomy, hand surgery, carpal tunnel surgery, knee arthroscopy, shoulder arthroplasty, and shoulder arthroscopy) were screened. Participants were enrolled from May 25, 2010, to July 25, 2014, and followed up for 2 years postoperatively. Intention-to-treat analysis was used in evaluation of the findings.Gabapentin, 1200 mg, preoperatively and 600 mg, 3 times a day postoperatively or active placebo (lorazepam, 0.5 mg) preoperatively followed by inactive placebo postoperatively for 72 hours.Primary outcome was time to pain resolution (5 consecutive reports of 0 of 10 possible levels of average pain at the surgical site on the numeric rating scale of pain). Secondary outcomes were time to opioid cessation (5 consecutive reports of no opioid use) and the proportion of participants with continued pain or opioid use at 6 months and 1 year.Of 1805 patients screened for enrollment, 1383 were excluded, including 926 who did not meet inclusion criteria and 273 who declined to participate. Overall, 8% of patients randomized were lost to follow-up. A total of 202 patients were randomized to active placebo and 208 patients were randomized to gabapentin in the intention-to-treat analysis (mean [SD] age, 56.7 [11.7] years; 256 (62.4%) women and 154 (37.6%) men). Baseline characteristics of the groups were similar. Perioperative gabapentin did not affect time to pain cessation (hazard ratio [HR], 1.04; 95% CI, 0.82-1.33; P = .73) in the intention-to-treat analysis. However, participants receiving gabapentin had a 24% increase in the rate of opioid cessation after surgery (HR, 1.24; 95% CI, 1.00-1.54; P = .05). No significant differences were noted in the number of adverse events as well as the rate of medication discontinuation due to sedation or dizziness (placebo, 42 of 202 [20.8%]; gabapentin, 52 of 208 [25.0%]).Perioperative administration of gabapentin had no effect on postoperative pain resolution, but it had a modest effect on promoting opioid cessation after surgery. The routine use of perioperative gabapentin may be warranted to promote opioid cessation and prevent chronic opioid use. Optimal dosing and timing of perioperative gabapentin in the context of specific operations to decrease opioid use should be addressed in further research.clinicaltrials.gov Identifier: NCT01067144.

  View details for PubMedID 29238824

• Local estrogen axis in the human bone microenvironment regulates estrogen receptor-positive breast cancer cells. Breast cancer research : BCR Amanatullah, D. F., Tamaresis, J. S., Chu, P. n., Bachmann, M. H., Hoang, N. M., Collyar, D. n., Mayer, A. T., West, R. B., Maloney, W. J., Contag, C. H., King, B. L. 2017; 19 (1): 121

  Abstract

  Approximately 70% of all breast cancers express the estrogen receptor, and are regulated by estrogen. While the ovaries are the primary source of estrogen in premenopausal women, most breast cancer is diagnosed following menopause, when systemic levels of this hormone decline. Estrogen production from androgen precursors is catalyzed by the aromatase enzyme. Although aromatase expression and local estrogen production in breast adipose tissue have been implicated in the development of primary breast cancer, the source of estrogen involved in the regulation of estrogen receptor-positive (ER+) metastatic breast cancer progression is less clear.Bone is the most common distant site of breast cancer metastasis, particularly for ER+ breast cancers. We employed a co-culture model using trabecular  bone tissues obtained from total hip replacement (THR) surgery specimens to study ER+ and estrogen receptor-negative (ER-) breast cancer cells within the human bone microenvironment. Luciferase-expressing ER+ (MCF-7, T-47D, ZR-75) and ER- (SK-BR-3, MDA-MB-231, MCF-10A) breast cancer cells were cultured directly on bone tissue fragments or in bone tissue-conditioned media, and monitored over time with bioluminescence imaging (BLI). Bone tissue-conditioned media were generated in the presence vs. absence of aromatase inhibitors, and testosterone. Bone tissue fragments were analyzed for aromatase expression by immunohistochemistry.ER+ breast cancer cells were preferentially sustained in co-cultures with bone tissues and bone tissue-conditioned media relative to ER- cells. Bone fragments analyzed by immunohistochemistry revealed expression of the aromatase enzyme. Bone tissue-conditioned media generated in the presence of testosterone had increased estrogen levels and heightened capacity to stimulate ER+ breast cancer cell proliferation. Pretreatment of cultured bone tissues with aromatase inhibitors, which inhibited estrogen production, reduced the capacity of conditioned media to stimulate ER+ cell proliferation.These results suggest that a local estrogen signaling axis regulates ER+ breast cancer cell viability and proliferation within the bone metastatic niche, and that aromatase inhibitors modulate this axis. Although endocrine therapies are highly effective in the treatment of ER+ breast cancer, resistance to these treatments reduces their efficacy. Characterization of estrogen signaling networks within the bone microenvironment will identify new strategies for combating metastatic progression and endocrine resistance.

  View details for PubMedID 29141657

  View details for PubMedCentralID PMC5688761

• Cortical Strut Allograft Support of Modular Femoral Junctions During Revision Total Hip Arthroplasty. journal of arthroplasty Lim, C. T., Amanatullah, D. F., Huddleston, J. I., Hwang, K. L., Maloney, W. J., Goodman, S. B. 2016

  Abstract

  There is risk of junction failure when using modular femoral stems for revision total hip arthroplasty (THA), especially with loss of bone stock in the proximal femur. Using a cortical strut allograft may provide additional support of a modular femoral construct in revision THA.We reviewed prospectively gathered clinical and radiographic data for 28 revision THAs performed from 2004 to 2014 using cementless modular femoral components with cortical strut allograft applied to supplement proximal femoral bone loss: 5 (18%) were fluted taper designs and 23 (82%) were porous cylindrical designs All the patients had a Paprosky grade IIIA or greater femoral defect. The mean follow-up was 5.4 ± 3.9 years.The Harris Hip Scores improved from 26 ± 10 points preoperatively to 71 ± 10 points at final follow-up (P < .001). The Western Ontario McMaster Universities Osteoarthritis Index scores improved from 45 ± 12 points preoperatively to 76 ± 12 points at final follow-up (P < .001). Eighty-nine percent (25 hips) of all revision or conversion THAs were in place at final follow-up. Three (11%) patients underwent reoperations, 2 for infection and 1 for periprosthetic fracture. There was no statistical significant change in femoral component alignment (P = .161) at final follow-up. Mean subsidence was 1.8 ± 1.3 mm at final follow-up. Femoral diameter increased from initial postoperative imaging to final follow-up imaging by a mean of 9.1 ± 5.1 mm (P < .001) and cortical width increased by a mean of 4.5 ± 2.2 mm (P < .001). Twenty-seven hips (96%) achieved union between the cortical strut allograft and the host femur.The use of a modular femoral stem in a compromised femur with a supplementary cortical strut allgraft is safe and provides satisfactory clinical and radiological outcomes.

  View details for DOI 10.1016/j.arth.2016.12.011

  View details for PubMedID 28130016

• Use of Cortical Strut Allograft After Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty. journal of arthroplasty Lim, C. T., Amanatullah, D. F., Huddleston, J. I., Hwang, K. L., Maloney, W. J., Goodman, S. B. 2016

  Abstract

  Cortical strut allografts restore bone stock and improve postoperative clinical scores after revision total hip arthroplasty (THA). However, use of a cortical strut allograft is implicated in delayed healing of an extended trochanteric osteotomy (ETO). To date, there are no reports directly comparing ETO with or without cortical strut allografts.We reviewed prospectively gathered data on 50 revision THAs performed from 2004-2014 using an ETO. We compared the demographic, radiological, and clinical outcome of patients with (16 hips) and without (34 hips) cortical strut allograft after an ETO.There were no significant differences in Western Ontario McMaster Universities Osteoarthritis Index or Harris Hip Score between the ETOs with and without a cortical strut allograft. Fifteen of the ETOs (94%) with a cortical strut allograft and 31 of the ETOs (91%) without a cortical strut allograft were in situ at final follow-up (P = 1.000). A higher proportion hips with cortical strut allograft (100%, 16 patients) had preoperative Paprosky grade bone loss more than IIIA compared to those without allograft (29%, 10 patients) (P < .001). There were no differences in femoral stem subsidence (P = .207), alignment (P = .934), or migration of the osteotomized fragment (P = .171). Fourteen of the ETOs (88%) in patients with cortical strut allograft united compared to 34 ETOs (100%) in patients without allograft (P = .095).Our study shows that the use of cortical strut allograft during revision THA with ETO does not reduce the rate of union, radiological or clinical outcomes.

  View details for DOI 10.1016/j.arth.2016.12.002

  View details for PubMedID 28110850

• CD24 enrichment protects while its loss increases susceptibility of juvenile chondrocytes towards inflammation ARTHRITIS RESEARCH & THERAPY Lee, J., Smeriglio, P., Dragoo, J., Maloney, W. J., Bhutani, N. 2016; 18

  Abstract

  Diseases associated with human cartilage, including rheumatoid arthritis (RA) and osteoarthritis (OA) have manifested age, mechanical stresses and inflammation as the leading risk factors. Although inflammatory processes are known to be upregulated upon aging, we sought to gain a molecular understanding of how aging affects the tissue-specific response to inflammation. In this report, we explored the role of cluster of differentiation 24 (CD24) in regulating differential inflammatory responses in juvenile and adult human chondrocytes.Differential cell-surface CD24 expression was assessed in juvenile and adult chondrocytes along with human induced pluripotent stem cell (hiPSC)-derived neonatal chondrocytes through gene expression and fluorescence-activated cell sorting (FACS) analyses. Loss of function of CD24 was achieved through silencing in chondrocytes and the effects on the response to inflammatory cues were assessed through gene expression and NFκB activity.CD24 expression in chondrocytes caused a differential response to cytokine-induced inflammation, with the CD24(high) juvenile chondrocytes being resistant to IL-1ß treatment as compared to CD24(low) adult chondrocytes. CD24 protects from inflammatory response by reducing NFκB activation, as an acute loss of CD24 via silencing led to an increase in NFκB activation. Moreover, the loss of CD24 in chondrocytes subsequently increased inflammatory and catabolic gene expression both in the absence and presence of IL-1ß.We have identified CD24 as a novel regulator of inflammatory response in cartilage that is altered during development and aging and could potentially be therapeutic in RA and OA.

  View details for DOI 10.1186/s13075-016-1183-y

  View details for Web of Science ID 000390276900003

  View details for PubMedID 27955675

  View details for PubMedCentralID PMC5153697

• Tibiofemoral Dislocation After Total Knee Arthroplasty. journal of arthroplasty Jethanandani, R. G., Maloney, W. J., Huddleston, J. I., Goodman, S. B., Amanatullah, D. F. 2016; 31 (10): 2282-2285

  Abstract

  Tibiofemoral dislocation after total knee arthroplasty (TKA) is a rare complication. Published case reports describe fewer than 6 patients, making conclusions about the etiology, epidemiology, complications, and treatment of tibiofemoral dislocation difficult. This case series highlights common demographic features, potential causes, and difficulties during the management of tibiofemoral dislocations after TKA.Between 2005 and 2014, 14 patients presented to our institution with a tibiofemoral dislocation. Patients were excluded if they had patellofemoral dislocation or subluxation without a tibiofemoral dislocation. We retrospectively reviewed patient demographics, time to first dislocation, number of dislocations, time to surgical intervention, complications, and potential etiologies of tibiofemoral dislocation.Twelve of 14 patients were female. Their mean body mass index was 33 ± 10 kg/m(2). Thirteen of 14 patients had a mean of 2.0 ± 1.4 dislocations. Four patients dislocated due to polyethylene damage and 5 due to ligamentous incompetence. Twelve of 14 patients required open surgical intervention. Complications in this patient population were common with 3 cases of infection, 7 cases of multiple dislocation, 2 cases of popliteal artery laceration, 1 case receiving a fusion, and 1 case receiving an amputation.Patients with tibiofemoral dislocation after TKA are predominantly obese, female, and have a high risk for complications. They dislocate predominantly because of polyethylene damage or ligamentous incompetence. Re-dislocation is common if treated with closed reduction alone.

  View details for DOI 10.1016/j.arth.2016.03.010

  View details for PubMedID 27084503

• Obesity is Associated With Early Total Hip Revision for Aseptic Loosening. journal of arthroplasty Electricwala, A. J., Narkbunnam, R., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2016; 31 (9): 217-220

  Abstract

  Obesity affects more than half a billion people worldwide, including one-third of men and women in the United States. Obesity is associated with higher postoperative complication rates after total hip arthroplasty (THA). It remains unknown whether obese patients progress to revision THA faster than nonobese patients.A total of 257 consecutive primary THAs referred to an academic tertiary care center for revision THA were retrospectively stratified according to preoperative body mass index (BMI), reason for revision THA, and time from primary to revision THA.When examining primary THAs referred for revision THA, increasing BMI adversely affected the mean time to revision THA. The percentage of primary THAs revised at 5 years was 25% for a BMI of 18-25, 38% for a BMI of 25-30, 56% for a BMI of 30-35, 73% for a BMI of 35-40, and 75% for a BMI of greater than 40 (P < .001). The percentage of primary THAs revised at 15 years was 70%, 82%, 87%, 94%, and 100%, respectively (P < .001). A significant increase in early revision THA for aseptic loosening/osteolysis in obese patients (56%, 23/41) when compared with the nonobese patients (12%, 10/83, P < .001, relative risk ratio = 4.7).Preoperative BMI influences the time of failure of primary THAs referred to an academic tertiary care for revision THA as well as the mechanism of failure. Specifically, obesity increased in the relative risk of early revision THA due to aseptic loosening/osteolysis by 4.7 fold.

  View details for DOI 10.1016/j.arth.2016.02.073

  View details for PubMedID 27108056

• Obesity is Associated With Early Total Hip Revision for Aseptic Loosening JOURNAL OF ARTHROPLASTY Electricwala, A. J., Narkbunnam, R., Huddleston, J. I., Maloney, W. J., Goodman, S. B., Amanatullah, D. F. 2016; 31 (9): S217-S220

  Abstract

  Obesity affects more than half a billion people worldwide, including one-third of men and women in the United States. Obesity is associated with higher postoperative complication rates after total hip arthroplasty (THA). It remains unknown whether obese patients progress to revision THA faster than nonobese patients.A total of 257 consecutive primary THAs referred to an academic tertiary care center for revision THA were retrospectively stratified according to preoperative body mass index (BMI), reason for revision THA, and time from primary to revision THA.When examining primary THAs referred for revision THA, increasing BMI adversely affected the mean time to revision THA. The percentage of primary THAs revised at 5 years was 25% for a BMI of 18-25, 38% for a BMI of 25-30, 56% for a BMI of 30-35, 73% for a BMI of 35-40, and 75% for a BMI of greater than 40 (P < .001). The percentage of primary THAs revised at 15 years was 70%, 82%, 87%, 94%, and 100%, respectively (P < .001). A significant increase in early revision THA for aseptic loosening/osteolysis in obese patients (56%, 23/41) when compared with the nonobese patients (12%, 10/83, P < .001, relative risk ratio = 4.7).Preoperative BMI influences the time of failure of primary THAs referred to an academic tertiary care for revision THA as well as the mechanism of failure. Specifically, obesity increased in the relative risk of early revision THA due to aseptic loosening/osteolysis by 4.7 fold.

  View details for DOI 10.1016/j.arth.2016.02.073

  View details for Web of Science ID 000382208900046

• Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up. Journal of hip preservation surgery Shapiro, L. M., Safran, M. R., Maloney, W. J., Goodman, S. B., Huddleston, J. I., Bellino, M. J., Scuderi, G. J., Abrams, G. D. 2016; 3 (3): 229-235

  Abstract

  Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy.

  View details for DOI 10.1093/jhps/hnw013

  View details for PubMedID 27583163

• Identification of Human Juvenile Chondrocyte-Specific Factors that Stimulate Stem Cell Growth TISSUE ENGINEERING PART A Taylor, S. E., Lee, J., Smeriglio, P., Razzaque, A., Smith, R. L., Dragoo, J. L., Maloney, W. J., Bhutani, N. 2016; 22 (7-8): 645-653

  Abstract

  Although regeneration of human cartilage is inherently inefficient, age is an important risk factor for osteoarthritis. Recent reports have provided compelling evidence that juvenile chondrocytes (from donors below 13 years of age) are more efficient at generating articular cartilage as compared to adult chondrocytes. However, the molecular basis for such a superior regenerative capability is not understood. To identify the cell-intrinsic differences between juvenile and adult cartilage, we have systematically profiled global gene expression changes between a small cohort of human neonatal/juvenile and adult chondrocytes. No such study is available for human chondrocytes although young and old bovine and equine cartilage have been recently profiled. Our studies have identified and validated new factors enriched in juvenile chondrocytes as compared to adult chondrocytes including secreted extracellular matrix factors chordin-like 1 (CHRDL1) and microfibrillar-associated protein 4 (MFAP4). Network analyses identified cartilage development pathways, epithelial-mesenchymal transition, and innate immunity pathways to be overrepresented in juvenile-enriched genes. Finally, CHRDL1 was observed to aid the proliferation and survival of bone marrow-derived human mesenchymal stem cells (hMSC) while maintaining their stem cell potential. These studies, therefore, provide a mechanism for how young cartilage factors can potentially enhance stem cell function in cartilage repair.

  View details for DOI 10.1089/ten.tea.2015.0366

  View details for Web of Science ID 000374761600007

  View details for PubMedID 26955889

• Removal of Well-Fixed Cementless Acetabular Components in Revision Total Hip Arthroplasty. Orthopedics Adelani, M. A., Goodman, S. B., Maloney, W. J., Huddleston, J. I. 2016; 39 (2): e280-4

  Abstract

  The Zimmer Explant Acetabular Cup Removal System (Warsaw, Indiana) has been touted as a superior method for removing well-fixed cementless acetabular components while minimizing bone loss; however, no comparative data support this. This study compares bone loss following the removal of well-fixed acetabular components with Aufranc gouges and with the Explant System. A review of 623 revision total hip arthroplasties (THAs) at the authors' institution between 2002 and 2013 identified cases involving the revision of well-fixed cementless hemispherical acetabular components for any reason except infection. Twenty-four cases using Aufranc gouges and 27 cases using the Explant System were included. The following surrogates for bone loss were used: (1) the difference between the initial acetabular component outer diameter (OD) and the final reamer OD; (2) the difference between the initial acetabular component OD and the new acetabular component OD; and (3) the use of impaction bone grafting. A 2-tailed Wilcoxon-Mann-Whitney test was used to assess the difference in bone loss between the 2 groups. The use of bone grafting was compared between the groups with the chi-square test. The median differences between the initial acetabular component and the final reamer (P=.004), as well as between the initial and new acetabular components (P=.002), were 2 mm less with the Explant System. Hips in the Aufranc group were more likely to have bone grafting (54% vs 26%; P=.04). These results suggest less bone loss when removing well-fixed acetabular components with the Zimmer Explant System compared with Aufranc gouges. [Orthopedics. 2016; 39(2):e280-e284.].

  View details for DOI 10.3928/01477447-20160129-04

  View details for PubMedID 26840697

• Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Zhang, Q., Goodman, S. B., Maloney, W. J., Huddleston, J. I. 2016; 474 (2): 459-464

  Abstract

  Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant.We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions.Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence.The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed.The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients.Level IV, therapeutic study.

  View details for DOI 10.1007/s11999-015-4480-x

  View details for Web of Science ID 000368021900033

  View details for PubMedCentralID PMC4709298

• Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup. Clinical orthopaedics and related research Zhang, Q., Goodman, S. B., Maloney, W. J., Huddleston, J. I. 2016; 474 (2): 459-64

  Abstract

  Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant.We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions.Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence.The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed.The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients.Level IV, therapeutic study.

  View details for DOI 10.1007/s11999-015-4480-x

  View details for PubMedID 26245165

  View details for PubMedCentralID PMC4709298

• Treatment of Periprosthetic Knee Infection With a Two-stage Protocol Using Static Spacers CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Lichstein, P., Su, S., Hedlund, H., Suh, G., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2016; 474 (1): 120-125

  Abstract

  Two-stage exchange arthroplasty is a standard approach for treating total knee arthroplasty periprosthetic joint infection in the United States, but whether this should be performed with a static antibiotic spacer or an articulating one that allows range of motion before reimplantation remains controversial. It is unclear if the advantages of articulating spacers (easier surgical exposure during reimplantation and improved postoperative flexion) outweigh the disadvantages of increased cost and complexity in the setting of similar rates of infection eradication.The purposes of this study were (1) to determine the ultimate range of motion; and (2) to determine the proportion of patients who remained free of infection at a minimum 2 years after treatment with static antibiotic spacers as part of a two-stage revision TKA for the treatment of periprosthetic joint infection.Between 1999 and 2011, we treated 121 patients with chronically infected TKAs, of whom three had medical comorbidities precluding a two-stage exchange, four had died before 2-year followup for reasons other than the surgical intervention, and seven were lost to followup. The remaining 107 patients (109 knees; 53 men and 54 women) were treated using a two-stage approach with static spacers and are evaluated here at a mean of 3.7 years (range, 2.0-9.8 years); no patients were treated with articulating spacers during this study period. Twenty-five percent (27 of 109) of the organisms isolated the first-stage procedure were resistant to methicillin and/or vancomycin. Median age at the time of reimplantation was 67 years (range, 42-89 years). Range of motion was measured by an independent physical therapist with a standard goniometer. Knee Society knee and function scores were calculated before the first stage and at the 2-year mark. Because many of these patients were treated before consensus definitions of infection were established, we made the diagnosis of infection (and established that a patient was believed to be free of infection) using the approaches prevalent at that time, which generally included presence of a sinus tract communicating directly with the implant, two positive tissue cultures, or a combination of cultures, fluid analysis, and serology.Postoperatively, 67 knees had full extension and no patients had a flexion contracture > 10°. Median flexion was 100° (range, 60°-139°). Thirty-nine knees had postoperative flexion > 120°. Ninety-four percent of patients were clinically free of infection at last followup.Our two-stage exchange protocol with static spacers yielded comparable flexion and infection eradication when compared with other recent studies that have used articulating spacers. The large proportion of resistant organisms is alarming. Future multicenter studies should compare static with articulating spacers and should evaluate both cost and efficacy, because our study suggests that adequate range of motion can be achieved without the added cost of the articulating spacer.Level IV, therapeutic study.

  View details for DOI 10.1007/s11999-015-4443-2

  View details for Web of Science ID 000368022600023

  View details for PubMedCentralID PMC4686492

• Long-Term Results of Total Hip Arthroplasty with 28-Millimeter Cobalt-Chromium Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years and Less JOURNAL OF ARTHROPLASTY Stambough, J. B., Pashos, G., Bohnenkamp, F. C., Maloney, W. J., Martell, J. M., Clohisy, J. C. 2016; 31 (1): 162-167

  View details for DOI 10.1016/j.arth.2015.07.025

  View details for Web of Science ID 000366677000032

  View details for PubMedID 26260785

• Treatment of Periprosthetic Knee Infection With a Two-stage Protocol Using Static Spacers. Clinical orthopaedics and related research Lichstein, P., Su, S., Hedlund, H., Suh, G., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2016; 474 (1): 120-5

  Abstract

  Two-stage exchange arthroplasty is a standard approach for treating total knee arthroplasty periprosthetic joint infection in the United States, but whether this should be performed with a static antibiotic spacer or an articulating one that allows range of motion before reimplantation remains controversial. It is unclear if the advantages of articulating spacers (easier surgical exposure during reimplantation and improved postoperative flexion) outweigh the disadvantages of increased cost and complexity in the setting of similar rates of infection eradication.The purposes of this study were (1) to determine the ultimate range of motion; and (2) to determine the proportion of patients who remained free of infection at a minimum 2 years after treatment with static antibiotic spacers as part of a two-stage revision TKA for the treatment of periprosthetic joint infection.Between 1999 and 2011, we treated 121 patients with chronically infected TKAs, of whom three had medical comorbidities precluding a two-stage exchange, four had died before 2-year followup for reasons other than the surgical intervention, and seven were lost to followup. The remaining 107 patients (109 knees; 53 men and 54 women) were treated using a two-stage approach with static spacers and are evaluated here at a mean of 3.7 years (range, 2.0-9.8 years); no patients were treated with articulating spacers during this study period. Twenty-five percent (27 of 109) of the organisms isolated the first-stage procedure were resistant to methicillin and/or vancomycin. Median age at the time of reimplantation was 67 years (range, 42-89 years). Range of motion was measured by an independent physical therapist with a standard goniometer. Knee Society knee and function scores were calculated before the first stage and at the 2-year mark. Because many of these patients were treated before consensus definitions of infection were established, we made the diagnosis of infection (and established that a patient was believed to be free of infection) using the approaches prevalent at that time, which generally included presence of a sinus tract communicating directly with the implant, two positive tissue cultures, or a combination of cultures, fluid analysis, and serology.Postoperatively, 67 knees had full extension and no patients had a flexion contracture > 10°. Median flexion was 100° (range, 60°-139°). Thirty-nine knees had postoperative flexion > 120°. Ninety-four percent of patients were clinically free of infection at last followup.Our two-stage exchange protocol with static spacers yielded comparable flexion and infection eradication when compared with other recent studies that have used articulating spacers. The large proportion of resistant organisms is alarming. Future multicenter studies should compare static with articulating spacers and should evaluate both cost and efficacy, because our study suggests that adequate range of motion can be achieved without the added cost of the articulating spacer.Level IV, therapeutic study.

  View details for DOI 10.1007/s11999-015-4443-2

  View details for PubMedID 26280681

  View details for PubMedCentralID PMC4686492

• Comprehensive Operative Note Templates for Primary and Revision Total Hip and Knee Arthroplasty. The open orthopaedics journal Electricwala, A. J., Amanatullah, D. F., Narkbunnam, R. I., Huddleston, J. I., Maloney, W. J., Goodman, S. B. 2016; 10: 725-731

  Abstract

  Adequate preoperative planning is the first and most crucial step in the successful completion of a revision total joint arthroplasty. The purpose of this study was to evaluate the availability, adequacy and accuracy of operative notes of primary surgeries in patients requiring subsequent revision and to construct comprehensive templates of minimum necessary information required in the operative notes to further simplify re-operations, if they should become necessary.The operative notes of 144 patients (80 revision THA's and 64 revision TKA's) who underwent revision total joint arthroplasty at Stanford Hospital and Clinics in the year 2013 were reviewed. We assessed the availability of operative notes and implant stickers prior to revision total joint arthroplasty. The availability of implant details within the operative notes was assessed against the available surgical stickers for adequacy and accuracy. Statistical comparisons were made using the Fischer-exact test and a P-value of less than 0.05 was considered statistically significant.The primary operative note was available in 68 of 144 revisions (47%), 39 of 80 revision THAs (49%) and 29 of 66 revision TKAs (44%, p = 0.619). Primary implant stickers were available in 46 of 144 revisions (32%), 26 of 80 revision THAs (32%) and 20 of 66 revision TKAs (30%, p = 0.859). Utilizing the operative notes and implant stickers combined identified accurate primary implant details in only 40 of the 80 revision THAs (50%) and 34 of all 66 revision TKAs (52%, p = 0.870).Operative notes are often unavailable or fail to provide the necessary information required which makes planning and execution of revision hip and knee athroplasty difficult. This emphasizes the need for enhancing the quality of operative notes and records of patient information. Based on this information, we provide comprehensive operative note templates for primary and revision total hip and knee arthroplasty.

  View details for DOI 10.2174/1874325001610010725

  View details for PubMedID 28144382

• Breast Cancer Cell Colonization of the Human Bone Marrow Adipose Tissue Niche NEOPLASIA Templeton, Z. S., Lie, W., Wang, W., Rosenberg-Hasson, Y., Alluri, R. V., Tamaresis, J. S., Bachmann, M. H., Lee, K., Maloney, W. J., Contag, C. H., King, B. L. 2015; 17 (12): 849-861

  Abstract

  Bone is a preferred site of breast cancer metastasis, suggesting the presence of tissue-specific features that attract and promote the outgrowth of breast cancer cells. We sought to identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization in the metastatic niche.Migration and colonization patterns of MDA-MB-231-fLuc-EGFP (luciferase-enhanced green fluorescence protein) and MCF-7-fLuc-EGFP breast cancer cells were studied in co-culture with cancellous bone tissue fragments isolated from 14 hip arthroplasties. Breast cancer cell migration into tissues and toward tissue-conditioned medium was measured in Transwell migration chambers using bioluminescence imaging and analyzed as a function of secreted factors measured by multiplex immunoassay. Patterns of breast cancer cell colonization were evaluated with fluorescence microscopy and immunohistochemistry.Enhanced MDA-MB-231-fLuc-EGFP breast cancer cell migration to bone-conditioned versus control medium was observed in 12/14 specimens (P = .0014) and correlated significantly with increasing levels of the adipokines/cytokines leptin (P = .006) and IL-1β (P = .001) in univariate and multivariate regression analyses. Fluorescence microscopy and immunohistochemistry of fragments underscored the extreme adiposity of adult human bone tissues and revealed extensive breast cancer cell colonization within the marrow adipose tissue compartment.Our results show that breast cancer cells migrate to human bone tissue-conditioned medium in association with increasing levels of leptin and IL-1β, and colonize the bone marrow adipose tissue compartment of cultured fragments. Bone marrow adipose tissue and its molecular signals may be important but understudied components of the breast cancer metastatic niche.

  View details for DOI 10.1016/j.neo.2015.11.005

  View details for Web of Science ID 000366560300001

  View details for PubMedID 26696367

  View details for PubMedCentralID PMC4688564

• Level of constraint in revision knee arthroplasty. Current reviews in musculoskeletal medicine Indelli, P. F., Giori, N., Maloney, W. 2015; 8 (4): 390-397

  Abstract

  Revision total knee arthroplasty (TKA) in the setting of major bone deficiency and/or soft tissue laxity might require increasing levels of constraint to restore knee stability. However, increasing the level of constraint not always correlates with mid-to-long-term satisfactory results. Recently, modular components as tantalum cones and titanium sleeves have been introduced to the market with the goal of obtaining better fixation where bone deficiency is an issue; theoretically, satisfactory meta-diaphyseal fixation can reduce the mechanical stress at the level of the joint line, reducing the need for high levels of constraint. This article reviews the recent literature on the surgical management of the unstable TKA with the goal to propose a modern surgical algorithm for adult reconstruction surgeons.

  View details for DOI 10.1007/s12178-015-9295-6

  View details for PubMedID 26373770

  View details for PubMedCentralID PMC4630229

• Highly cross-linked polyethylene improves wear and mid-term failure rates for young total hip arthroplasty patients. Hip international Keeney, J. A., Martell, J. M., Pashos, G., Nelson, C. J., Maloney, W. J., Clohisy, J. C. 2015; 25 (5): 435-441

  Abstract

  We compared clinical outcomes and polyethylene wear for 2 young primary THA patient cohorts (<50 years of age) at mid-term follow-up. In total, 72 patients (84 hips) received a coventional polyethylene liner (CPE) and 84 patients (89 hips) received a highly cross-linked polyethylene liner (HXLPE). Mean Harris Hip Score improved to 81 points for both groups. UCLA activity scores were higher for HXLPE patients (6.0 vs 5.3, p = 0.03), with lower mean linear wear (0.02 vs 0.13 mm/year, p<0.001) and lower mean volumetric wear (75.1 vs 229.8 mm3, p<0.001) at an average of 70 months follow-up. No HXLPE patient required revision for wear related concerns, compared to 5 CPE patients with revision for aseptic loosening or impending radiographic failure (0% vs 5.9%, p = 0.02). HXLPE is associated with reduced wear among young, active THA patients without increased risk of early mechanical failure.

  View details for DOI 10.5301/hipint.5000242

  View details for PubMedID 25907392

• Musculoskeletal regeneration research network: A global initiative JOURNAL OF ORTHOPAEDIC TRANSLATION Chan, K., Rolf, C. G., Qin, L., Fellaender-Tsai, L., Castelein, R. M., Saris, D. F., Malda, J., Richards, G., Goodman, S. B., Tuan, R. S., Maloney, W., Lidgren, L., Hopkins, C., Fu, S., Li, G., Ding, M., Tang, T., Zhang, X., Wei, L., Sun, H. B., Ouyang, H. 2015; 3 (4): 160–65

  View details for PubMedID 30035054

• Early induction of a prechondrogenic population allows efficient generation of stable chondrocytes from human induced pluripotent stem cells FASEB JOURNAL Lee, J., Taylor, S. E., Smeriglio, P., Lai, J., Maloney, W. J., Yang, F., Bhutani, N. 2015; 29 (8): 3399-3410

  Abstract

  Regeneration of human cartilage is inherently inefficient; an abundant autologous source, such as human induced pluripotent stem cells (hiPSCs), is therefore attractive for engineering cartilage. We report a growth factor-based protocol for differentiating hiPSCs into articular-like chondrocytes (hiChondrocytes) within 2 weeks, with an overall efficiency >90%. The hiChondrocytes are stable and comparable to adult articular chondrocytes in global gene expression, extracellular matrix production, and ability to generate cartilage tissue in vitro and in immune-deficient mice. Molecular characterization identified an early SRY (sex-determining region Y) box (Sox)9(low) cluster of differentiation (CD)44(low)CD140(low) prechondrogenic population during hiPSC differentiation. In addition, 2 distinct Sox9-regulated gene networks were identified in the Sox9(low) and Sox9(high) populations providing novel molecular insights into chondrogenic fate commitment and differentiation. Our findings present a favorable method for generating hiPSC-derived articular-like chondrocytes. The hiChondrocytes are an attractive cell source for cartilage engineering because of their abundance, autologous nature, and potential to generate articular-like cartilage rather than fibrocartilage. In addition, hiChondrocytes can be excellent tools for modeling human musculoskeletal diseases in a dish and for rapid drug screening.-Lee, J., Taylor, S. E. B., Smeriglio, P., Lai, J., Maloney, W. J., Yang, F., Bhutani, N. Early induction of a prechondrogenic population allows efficient generation of stable chondrocytes from human induced pluripotent stem cells.

  View details for DOI 10.1096/fj.14-269720

  View details for Web of Science ID 000358796900027

  View details for PubMedID 25911615

• Interaction Between Osteoarthritic Chondrocytes and Adipose-Derived Stem Cells Is Dependent on Cell Distribution in Three-Dimension and Transforming Growth Factor-ß3 Induction. Tissue engineering. Part A Lai, J. H., Rogan, H., Kajiyama, G., Goodman, S. B., Smith, R. L., Maloney, W., Yang, F. 2015; 21 (5-6): 992-1002

  Abstract

  Stem cells hold great promise for treating cartilage degenerative diseases such as osteoarthritis (OA). The efficacy of stem cell-based therapy for cartilage repair is highly dependent on their interactions with local cells in the joint. This study aims at evaluating the interactions between osteoarthritic chondrocytes (OACs) and adipose-derived stem cells (ADSCs) using three dimensional (3D) biomimetic hydrogels. To examine the effects of cell distribution on such interactions, ADSCs and OACs were co-cultured in 3D using three co-culture models: conditioned medium (CM), bi-layered, and mixed co-culture with varying cell ratios. Furthermore, the effect of transforming growth factor (TGF)-β3 supplementation on ADSC-OAC interactions and the resulting cartilage formation was examined. Outcomes were analyzed using quantitative gene expression, cell proliferation, cartilage matrix production, and histology. TGF-β3 supplementation led to a substantial increase in cartilage matrix depositions in all groups, but had differential effects on OAC-ADSC interactions in different co-culture models. In the absence of TGF-β3, CM or bi-layered co-culture had negligible effects on gene expression or cartilage formation. With TGF-β3 supplementation, CM and bi-layered co-culture inhibited cartilage formation by both ADSCs and OACs. In contrast, a mixed co-culture with moderate OAC ratios (25% and 50%) resulted in synergistic interactions with enhanced cartilage matrix deposition and reduced catabolic marker expression. Our results suggested that the interaction between OACs and ADSCs is highly dependent on cell distribution in 3D and soluble factors, which should be taken into consideration when designing stem cell-based therapy for treating OA patients.

  View details for DOI 10.1089/ten.TEA.2014.0244

  View details for PubMedID 25315023

• Collagen VI Enhances Cartilage Tissue Generation by Stimulating Chondrocyte Proliferation. Tissue engineering. Part A Smeriglio, P., Dhulipala, L., Lai, J. H., Goodman, S. B., Dragoo, J. L., Smith, R. L., Maloney, W. J., Yang, F., Bhutani, N. 2015; 21 (3-4): 840-849

  Abstract

  Regeneration of human cartilage is inherently inefficient. Current cell-based approaches for cartilage repair, including autologous chondrocytes, are limited by the paucity of cells, associated donor site morbidity, and generation of functionally inferior fibrocartilage rather than articular cartilage. Upon investigating the role of collagen VI (Col VI), a major component of the chondrocyte pericellular matrix (PCM), we observe that soluble Col VI stimulates chondrocyte proliferation. Interestingly, both adult and osteoarthritis chondrocytes respond to soluble Col VI in a similar manner. The proliferative effect is, however, strictly due to the soluble Col VI as no proliferation is observed upon exposure of chondrocytes to immobilized Col VI. Upon short Col VI treatment in 2D monolayer culture, chondrocytes maintain high expression of characteristic chondrocyte markers like Col2a1, agc, and Sox9 whereas the expression of the fibrocartilage marker Collagen I (Col I) and of the hypertrophy marker Collagen X (Col X) is minimal. Additionally, Col VI-expanded chondrocytes show a similar potential to untreated chondrocytes in engineering cartilage in 3D biomimetic hydrogel constructs. Our study has, therefore, identified soluble Col VI as a biologic that can be useful for the expansion and utilization of scarce sources of chondrocytes, potentially for autologous chondrocyte implantation. Additionally, our results underscore the importance of further investigating the changes in chondrocyte PCM with age and disease and the subsequent effects on chondrocyte growth and function.

  View details for DOI 10.1089/ten.TEA.2014.0375

  View details for PubMedID 25257043

• Comparative potential of juvenile and adult human articular chondrocytes for cartilage tissue formation in three-dimensional biomimetic hydrogels. Tissue engineering. Part A Smeriglio, P., Lai, J. H., Dhulipala, L., Behn, A. W., Goodman, S. B., Smith, R. L., Maloney, W. J., Yang, F., Bhutani, N. 2015; 21 (1-2): 147-155

  Abstract

  Regeneration of human articular cartilage is inherently limited and extensive efforts have focused on engineering the cartilage tissue. Various cellular sources have been studied for cartilage tissue engineering including adult chondrocytes, as well as embryonic or adult stem cells. Juvenile chondrocytes (from donors below 13 years of age) have recently been reported to be a promising cell source for cartilage regeneration. Previous studies have compared the potential of adult and juvenile chondrocytes or adult and osteoarthritic (OA) chondrocytes. To comprehensively characterize the comparative potential of young, old and diseased chondrocytes, here we examined cartilage formation by juvenile, adult and OA chondrocytes in 3D biomimetic hydrogels composed of poly(ethylene glycol) and chondroitin sulfate. All three human articular chondrocytes were encapsulated in the 3D biomimetic hydrogels and cultured for 3 or 6 weeks to allow maturation and extracellular matrix formation. Outcomes were analyzed using quantitative gene expression, immunofluorescence staining, biochemical assays, and mechanical testing. After 3 and 6 weeks, juvenile chondrocytes showed a greater upregulation of chondrogenic gene expression than adult chondrocytes, while OA chondrocytes showed a downregulation. Aggrecan and type II collagen deposition and GAG accumulation were high for juvenile and adult chondrocytes but not for OA chondrocytes. Similar trend was observed in the compressive moduli of the cartilage constructs generated by the three different chondrocytes. In conclusion, the juvenile, adult and OA chondrocytes showed differential responses in the 3D biomimetic hydrogels. The 3D culture model described here may also provide a useful tool to further study the molecular differences among chondrocytes from different stages, which can help elucidate the mechanisms for age-related decline in the intrinsic capacity for cartilage repair.

  View details for DOI 10.1089/ten.TEA.2014.0070

  View details for PubMedID 25054343

• Methods for culturing human femur tissue explants to study breast cancer cell colonization of the metastatic niche. Journal of visualized experiments : JoVE Templeton, Z. S., Bachmann, M. H., Alluri, R. V., Maloney, W. J., Contag, C. H., King, B. L. 2015

  Abstract

  Bone is the most common site of breast cancer metastasis. Although it is widely accepted that the microenvironment influences cancer cell behavior, little is known about breast cancer cell properties and behaviors within the native microenvironment of human bone tissue.We have developed approaches to track, quantify and modulate human breast cancer cells within the microenvironment of cultured human bone tissue fragments isolated from discarded femoral heads following total hip replacement surgeries. Using breast cancer cells engineered for luciferase and enhanced green fluorescent protein (EGFP) expression, we are able to reproducibly quantitate migration and proliferation patterns using bioluminescence imaging (BLI), track cell interactions within the bone fragments using fluorescence microscopy, and evaluate breast cells after colonization with flow cytometry. The key advantages of this model include: 1) a native, architecturally intact tissue microenvironment that includes relevant human cell types, and 2) direct access to the microenvironment, which facilitates rapid quantitative and qualitative monitoring and perturbation of breast and bone cell properties, behaviors and interactions. A primary limitation, at present, is the finite viability of the tissue fragments, which confines the window of study to short-term culture. Applications of the model system include studying the basic biology of breast cancer and other bone-seeking malignancies within the metastatic niche, and developing therapeutic strategies to effectively target breast cancer cells in bone tissues.

  View details for DOI 10.3791/52656

  View details for PubMedID 25867136

• Novel osteoinductive photo-cross-linkable chitosan-lactide-fibrinogen hydrogels enhance bone regeneration in critical size segmental bone defects ACTA BIOMATERIALIA Kim, S., Bedigrew, K., Guda, T., Maloney, W. J., Park, S., Wenke, J. C., Yang, Y. P. 2014; 10 (12): 5021-5033

  Abstract

  The purpose of this study was to develop and characterize a novel photo-cross-linkable chitosan-lactide-fibrinogen (CLF) hydrogel and evaluate the efficacy of bone morphogenetic protein-2 (BMP-2) containing a CLF hydrogel for osteogenesis in vitro and in vivo. We synthesized the CLF hydrogels and characterized their chemical structure, degradation rate, compressive modulus and in vitro BMP-2 release kinetics. We evaluated bioactivities of the BMP-2 containing CLF hydrogels (0, 50, 100 and 500ngml(-1)) in vitro using W-20-17 preosteoblast mouse bone marrow stromal cells and C2C12 mouse myoblast cells. The effect of BMP-2 containing CLF gels (0, 0.5, 1, 2 and 5μg) on bone formation was evaluated using rat critical size segmental bone defects for 4weeks. Fourier transform infrared spectroscopy spectra and scanning electron microscopy images showed chemical and structural changes by the addition of fibrinogen into the chitosan-lactide copolymer. The incorporation of fibrinogen molecules significantly increased the compressive modulus of the hydrogels. The in vitro BMP-2 release study showed initial burst releases from the CLF hydrogels followed by sustained releases, regardless of the concentration of the BMP-2 over 4weeks. Cells in all groups were viable in the presence of the hydrogels regardless of BMP-2 doses, indicating non-cytotoxicity of hydrogels. Alkaline phosphate activity and mineralization of cells exhibited dose dependence on BMP-2 containing CLF hydrogels. Radiography, microcomputed tomography and histology confirmed that the BMP-2 containing CLF hydrogels prompted neo-osteogenesis and accelerated healing of the defects in a dose-dependent manner. Thus the CLF hydrogel is a promising delivery system of growth factors for bone regeneration.

  View details for DOI 10.1016/j.actbio.2014.08.028

  View details for Web of Science ID 000345468300011

  View details for PubMedCentralID PMC4252590

• Novel osteoinductive photo-cross-linkable chitosan-lactide-fibrinogen hydrogels enhance bone regeneration in critical size segmental bone defects. Acta biomaterialia Kim, S., Bedigrew, K., Guda, T., Maloney, W. J., Park, S., Wenke, J. C., Yang, Y. P. 2014; 10 (12): 5021-5033

  Abstract

  The purpose of this study was to develop and characterize a novel photo-cross-linkable chitosan-lactide-fibrinogen (CLF) hydrogel and evaluate the efficacy of bone morphogenetic protein-2 (BMP-2) containing a CLF hydrogel for osteogenesis in vitro and in vivo. We synthesized the CLF hydrogels and characterized their chemical structure, degradation rate, compressive modulus and in vitro BMP-2 release kinetics. We evaluated bioactivities of the BMP-2 containing CLF hydrogels (0, 50, 100 and 500ngml(-1)) in vitro using W-20-17 preosteoblast mouse bone marrow stromal cells and C2C12 mouse myoblast cells. The effect of BMP-2 containing CLF gels (0, 0.5, 1, 2 and 5μg) on bone formation was evaluated using rat critical size segmental bone defects for 4weeks. Fourier transform infrared spectroscopy spectra and scanning electron microscopy images showed chemical and structural changes by the addition of fibrinogen into the chitosan-lactide copolymer. The incorporation of fibrinogen molecules significantly increased the compressive modulus of the hydrogels. The in vitro BMP-2 release study showed initial burst releases from the CLF hydrogels followed by sustained releases, regardless of the concentration of the BMP-2 over 4weeks. Cells in all groups were viable in the presence of the hydrogels regardless of BMP-2 doses, indicating non-cytotoxicity of hydrogels. Alkaline phosphate activity and mineralization of cells exhibited dose dependence on BMP-2 containing CLF hydrogels. Radiography, microcomputed tomography and histology confirmed that the BMP-2 containing CLF hydrogels prompted neo-osteogenesis and accelerated healing of the defects in a dose-dependent manner. Thus the CLF hydrogel is a promising delivery system of growth factors for bone regeneration.

  View details for DOI 10.1016/j.actbio.2014.08.028

  View details for PubMedID 25174669

• In vitro evaluation of photo-crosslinkable chitosan-lactide hydrogels for bone tissue engineering JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS Kim, S., Kang, Y., Mercado-Pagan, A. E., Maloney, W. J., Yang, Y. 2014; 102 (7): 1393-1406

  View details for DOI 10.1002/jbm.b.33118

  View details for Web of Science ID 000342963000004

• In vitro evaluation of photo-crosslinkable chitosan-lactide hydrogels for bone tissue engineering. Journal of biomedical materials research. Part B, Applied biomaterials Kim, S., Kang, Y., Mercado-Pagán, Á. E., Maloney, W. J., Yang, Y. 2014; 102 (7): 1393-1406

  Abstract

  Here we report the development and characterization of novel photo-crosslinkable chitosan-lactide (Ch-LA) hydrogels for bone tissue engineering. We synthesized the hydrogels based on Ch, LA, and methacrylic anhydride (MA), and examined their chemical structures, degradation rates, compressive moduli, and protein release kinetics. We also evaluated the cytotoxicity of the hydrogels and delivery efficacy of bone morphogenetic protein-2 (BMP-2) on osteoblast differentiation and mineralization using W-20-17 preosteoblast mouse bone marrow stromal cells and C2C12 mouse myoblast cells. NMR and FTIR revealed that the hydrogels were formed via amidation and esterification between Ch and LA, and methacrylation for photo-crosslinkable networks. Addition of a hydrophobic LA moiety to a hydrophilic Ch chain increased swellability, softness, and degradation rate of the photo-crosslinkable Ch-LA hydrogels. Changes in Ch/LA ratio and UV exposure time significantly affected compressive modulus and protein release kinetics. The photo-crosslinkable Ch-LA hydrogels were not cytotoxic regardless of the composition and UV crosslinking time. Higher alkaline phosphatase activities of both W-20-17 and C2C12 cells were observed in the less-crosslinked hydrogels at day 5. Mineralization was enhanced by sustained BMP-2 release from the hydrogels, but was cell type dependent. This photo-crosslinkable Ch-LA hydrogel is a promising carrier for growth factors.

  View details for DOI 10.1002/jbm.b.33118

  View details for PubMedID 24500890

• Clinical recovery from surgery correlates with single-cell immune signatures SCIENCE TRANSLATIONAL MEDICINE Gaudilliere, B., Fragiadakis, G. K., Bruggner, R. V., Nicolau, M., Finck, R., Tingle, M., Silva, J., Ganio, E. A., Yeh, C. G., Maloney, W. J., Huddleston, J. I., Goodman, S. B., Davis, M. M., Bendall, S. C., Fantl, W. J., Angst, M. S., Nolan, G. P. 2014; 6 (255)

  Abstract

  Delayed recovery from surgery causes personal suffering and substantial societal and economic costs. Whether immune mechanisms determine recovery after surgical trauma remains ill-defined. Single-cell mass cytometry was applied to serial whole-blood samples from 32 patients undergoing hip replacement to comprehensively characterize the phenotypic and functional immune response to surgical trauma. The simultaneous analysis of 14,000 phosphorylation events in precisely phenotyped immune cell subsets revealed uniform signaling responses among patients, demarcating a surgical immune signature. When regressed against clinical parameters of surgical recovery, including functional impairment and pain, strong correlations were found with STAT3 (signal transducer and activator of transcription), CREB (adenosine 3',5'-monophosphate response element-binding protein), and NF-κB (nuclear factor κB) signaling responses in subsets of CD14(+) monocytes (R = 0.7 to 0.8, false discovery rate <0.01). These sentinel results demonstrate the capacity of mass cytometry to survey the human immune system in a relevant clinical context. The mechanistically derived immune correlates point to diagnostic signatures, and potential therapeutic targets, that could postoperatively improve patient recovery.

  View details for DOI 10.1126/scitranslmed.3009701

  View details for Web of Science ID 000343316800006

• Clinical recovery from surgery correlates with single-cell immune signatures. Science translational medicine Gaudillière, B., Fragiadakis, G. K., Bruggner, R. V., Nicolau, M., Finck, R., Tingle, M., Silva, J., Ganio, E. A., Yeh, C. G., Maloney, W. J., Huddleston, J. I., Goodman, S. B., Davis, M. M., Bendall, S. C., Fantl, W. J., Angst, M. S., Nolan, G. P. 2014; 6 (255): 255ra131-?

  Abstract

  Delayed recovery from surgery causes personal suffering and substantial societal and economic costs. Whether immune mechanisms determine recovery after surgical trauma remains ill-defined. Single-cell mass cytometry was applied to serial whole-blood samples from 32 patients undergoing hip replacement to comprehensively characterize the phenotypic and functional immune response to surgical trauma. The simultaneous analysis of 14,000 phosphorylation events in precisely phenotyped immune cell subsets revealed uniform signaling responses among patients, demarcating a surgical immune signature. When regressed against clinical parameters of surgical recovery, including functional impairment and pain, strong correlations were found with STAT3 (signal transducer and activator of transcription), CREB (adenosine 3',5'-monophosphate response element-binding protein), and NF-κB (nuclear factor κB) signaling responses in subsets of CD14(+) monocytes (R = 0.7 to 0.8, false discovery rate <0.01). These sentinel results demonstrate the capacity of mass cytometry to survey the human immune system in a relevant clinical context. The mechanistically derived immune correlates point to diagnostic signatures, and potential therapeutic targets, that could postoperatively improve patient recovery.

  View details for DOI 10.1126/scitranslmed.3009701

  View details for PubMedID 25253674

• Current Modes of Failure in TKA: Infection, Instability, and Stiffness Predominate. Clinical orthopaedics and related research Le, D. H., Goodman, S. B., Maloney, W. J., Huddleston, J. I. 2014; 472 (7): 2197-2200

  Abstract

  Historically, polyethylene wear and its sequelae (osteolysis, late instability, aseptic loosening) were common causes for revision total knee arthroplasty (TKA). Recently, polyethylene manufacturing has become more consistent; furthermore, a clearer understanding of the importance of oxidation on polyethylene performance led to packaging of the polyethylene bearings in an inert environment. This improved the quality and consistency of polyethylene used in TKA, raising the question of whether different failure modes now predominate after TKA.The purpose of this study was to determine the current reasons for (1) early and (2) late failures after TKA at one high-volume arthroplasty center.We reviewed all first-time revision TKAs performed between 2001 and 2011 at one institution, yielding a group of 253 revision TKAs in 251 patients. Mean age at the time of revision was 64 years (SD 10 years). Mean time to revision was 35 months (SD 23 months). Preoperative evaluations, laboratory data, radiographs, and intraoperative findings were used to determine causes for revision. Early failure was defined as revision within 2 years of the index procedure. The primary failure mechanism was determined by the operating surgeon.Early failure accounted for 46% (116 of 253) of all revisions with infection (28 of 116 [24%]), instability (30 of 116 [26%]), and stiffness (21 of 116 [18%]) being the leading causes. Late failure accounted for 54% (137 of 253) of all revisions with the most common causes including infection (34 of 137 [25%]), instability (24 of 137 [18%]), and stiffness (19 of 253 [14%]). Polyethylene wear was implicated as the failure mechanism in 2% of early cases (two of 116) and 9% of late cases (13 of 137).In contrast to previous studies, wear-related implant failure in TKA was relatively uncommon in this series. Changes in polyethylene manufacturing, sterilization, and storage may have accounted for some of this difference; however, longer-term followup will be required to verify this finding. Infection, instability, and stiffness represent the most common causes of early and late failure. Strategies to improve outcomes in TKA should be aimed at infection prophylaxis and treatment, surgical technique, and patient selection.Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-014-3540-y

  View details for PubMedID 24615421

• Outcome of Porous Tantalum Acetabular Components for Paprosky Type 3 and 4 Acetabular Defects JOURNAL OF ARTHROPLASTY Batuyong, E. D., Brock, H. S., Thiruvengadam, N., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2014; 29 (6): 1318-1322

  Abstract

  Porous tantalum acetabular implants provide a potential solution for dealing with significant acetabular bone loss. This study reviews 24 acetabular revisions using tantalum implants for Paprosky type 3 and 4 defects. The mean Harris Hip Score improved from 35±19 (range, 4-71) to 88±14 (range, 41-100), p<0.0001. Postoperative radiographs showed radiolucent lines in 14 hips with a mean width of 1.3±1.0mm (range, 0.27-4.37mm). No gaps enlarged and 71% of them disappeared at a mean of 13±10months (range, 3-29months). At a mean follow-up of 37±14months (range, 24-66months), 22 reconstructions showed radiograpic evidence of osseointegration (92%). The two failures were secondary to septic loosening. When dealing with severe acetabular bone loss, porous tantalum acetabular components show promising short-term results.

  View details for DOI 10.1016/j.arth.2013.12.002

  View details for Web of Science ID 000338115400048

• Outcome of porous tantalum acetabular components for paprosky type 3 and 4 acetabular defects. The Journal of arthroplasty Batuyong, E. D., Brock, H. S., Thiruvengadam, N., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2014; 29 (6): 1318-22

  Abstract

  Porous tantalum acetabular implants provide a potential solution for dealing with significant acetabular bone loss. This study reviews 24 acetabular revisions using tantalum implants for Paprosky type 3 and 4 defects. The mean Harris Hip Score improved from 35±19 (range, 4-71) to 88±14 (range, 41-100), p<0.0001. Postoperative radiographs showed radiolucent lines in 14 hips with a mean width of 1.3±1.0mm (range, 0.27-4.37mm). No gaps enlarged and 71% of them disappeared at a mean of 13±10months (range, 3-29months). At a mean follow-up of 37±14months (range, 24-66months), 22 reconstructions showed radiograpic evidence of osseointegration (92%). The two failures were secondary to septic loosening. When dealing with severe acetabular bone loss, porous tantalum acetabular components show promising short-term results.

  View details for DOI 10.1016/j.arth.2013.12.002

  View details for PubMedID 24405625

• What is the Prognosis of Revision Total Hip Arthroplasty in Patients 55 Years and Younger? CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Adelani, M. A., Crook, K., Barrack, R. L., Maloney, W. J., Clohisy, J. C. 2014; 472 (5): 1518-1525

  Abstract

  Revision THAs are expected to increase; however, few studies have characterized the prognosis of revision THAs in younger patients.We performed a case-control study to evaluate intermediate-term survivorship, complications, and hip and activity scores after revision THAs in patients 55 years and younger, compared these outcomes with the results of primary THAs in a matched patient population, and evaluated risk factors for failed revisions.Ninety-three patients (103 hips) had a minimum of 4 years after revision THA, died, or had rerevision surgery. They were matched with 98 patients (103 hips) with primary THAs. Survivorship, complications, and clinical outcomes were compared between the groups using t-tests. Risk factors for failure also were assessed with chi-square analysis.At mean followup of 6.7 years, 71 revision THAs (69%) survived, compared with 102 (99%) primary THAs (odds ratio [OR], 45.9; 95% CI, 16.5-128.4; p < 0.001). Complications occurred in 29% of the revision group and 6% of the primary group (OR, 6.64; 95% CI, 4.14-10.67; p < 0.001). After revision THA, the average improvement in Harris hip score was 19.2 compared with 34.4 after primary THA (p < 0.001). The UCLA activity score improved by an average of 0.87 after revision compared with 2.36 after primary THA (p < 0.001). Conventional polyethylene was associated with failure after revision THA (OR, 2.98; 95% CI, 1.87-4.76; p = 0.004).At intermediate-term followup, young patients undergoing revision THAs had markedly higher failure and complication rates and more modest clinical improvements compared with patients in a matched cohort who had primary THAs.Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-013-3377-9

  View details for Web of Science ID 000334180400026

  View details for PubMedID 24249534

• Fibronectin-aggrecan complex as a marker for cartilage degradation in non-arthritic hips. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Abrams, G. D., Safran, M. R., Shapiro, L. M., Maloney, W. J., Goodman, S. B., Huddleston, J. I., Bellino, M. J., Scuderi, G. J. 2014; 22 (4): 768-773

  Abstract

  To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis.Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin-aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann-Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant.Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p < 0.001). FAC had significantly higher concentration in those without radiographic evidence of OA undergoing microfracture versus those not receiving microfracture (p < 0.05).There was a significantly higher FAC concentration in patients without radiographic OA. Additionally, those undergoing microfracture had increased levels of FAC. As FAC is a cartilage breakdown product, no significant amounts may be present in those with OA. In contrast, those undergoing microfracture have focal area(s) of cartilage breakdown. These data suggest that FAC may be useful in predicting cartilage pathology in those patients with hip pain but without radiographic evidence of arthritis.Diagnostic, Level III.

  View details for DOI 10.1007/s00167-014-2863-2

  View details for PubMedID 24477496

• Monitoring Dynamic Interactions Between Breast Cancer Cells and Human Bone Tissue in a Co-culture Model. Molecular imaging and biology Contag, C. H., Lie, W., Bammer, M. C., Hardy, J. W., Schmidt, T. L., Maloney, W. J., King, B. L. 2014; 16 (2): 158-166

  Abstract

  Bone is a preferential site of breast cancer metastasis, and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue.Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell proliferation and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX(®) immunoassays.BLI demonstrated increased MDA-MB-231-fLuc cell proliferation (p < 0.001) in the presence vs. absence of bones and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc cell colonization of bone, and MILLIPLEX(®) profiles of culture supernatants suggested breast/bone crosstalk.Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays.

  View details for DOI 10.1007/s11307-013-0685-0

  View details for PubMedID 24008275

• Causes of instability after total knee arthroplasty. journal of arthroplasty Song, S. J., Detch, R. C., Maloney, W. J., Goodman, S. B., Huddleston, J. I. 2014; 29 (2): 360-364

  Abstract

  The purpose of the present study was to characterize the underlying causes that lead to instability after total knee arthroplasty (TKA). We reviewed 83 revision TKAs (79 patients) performed for instability. After detailed analysis of patient's history, physical examination, operative report and radiographs, we identified six categories: flexion/extension gap mismatch, component malposition, isolated ligament insufficiency, extensor mechanism insufficiency, component loosening, and global instability. Twenty-five knees presented with multi-factorial instability. When these knees were classified according to the most fundamental category, each category above included 24, 12, 11, 10, 10 and 16 knees respectively. The unstable TKA may result from a variety of distinct etiologies which must be identified and treated at the time of revision. The revision TKA could be tailored to the specific causes.

  View details for DOI 10.1016/j.arth.2013.06.023

  View details for PubMedID 23896358

• Monitoring Dynamic Interactions Between Breast Cancer Cells and Human Bone Tissue in a Co-culture Model Molecular Imaging and Biology Contag, C. H., Lie, W., Bammer, M. C., Hardy, J. W., Schmidt, T. L., Maloney, W. J., King, B. L. 2014; 16 (2): 158-166

  Abstract

  Bone is a preferential site of breast cancer metastasis, and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue.Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell proliferation and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX(®) immunoassays.BLI demonstrated increased MDA-MB-231-fLuc cell proliferation (p < 0.001) in the presence vs. absence of bones and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc cell colonization of bone, and MILLIPLEX(®) profiles of culture supernatants suggested breast/bone crosstalk.Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays.

  View details for DOI 10.1007/s11307-013-0685-0

• Advances in acetabular reconstruction in revision total hip arthroplasty: maximizing function and outcomes after treatment of periacetabular osteolysis around the well-fixed shell. Instructional course lectures Hall, A., Eilers, M., Hansen, R., Robinson, B. S., Maloney, W. J., Paprosky, W. G., Ries, M. D., Saleh, K. J. 2014; 63: 209-218

  Abstract

  As the incidence of primary and revision hip arthroplasty increases, the need for a comprehensive approach to acetabular revision cannot be overstated. In the presence of osteolysis, there is a substantial population of patients with a well-fixed acetabular shell. It will be helpful to orthopaedic surgeons to review the classification of acetabular defects, techniques for exposing an acetabular component when the femoral component will be retained, methods of facilitating access to osteolytic lesions, the principles of bone grafting, options for liner fixation, and when removal of a well-fixed shell is necessary.

  View details for PubMedID 24720307

• Acetabular reconstruction in revision total hip arthroplasty: maximizing function and outcomes in protrusio and cavitary defects. Instructional course lectures Dahl, B., McNeely, C., Robinson, B. S., Maloney, W. J., Paprosky, W. G., Ries, M. D., Saleh, K. J. 2014; 63: 219-225

  Abstract

  Osteolysis in the periacetabular region is a common long-term complication of total hip arthroplasty that can lead to bone loss, implant loosening, and protrusio. Several systems have been developed for classifying osteolysis and guiding treatment. Options such as bone grafting or augmentation, with exchange of the bearing surface and, in some cases, revision of the acetabular component, can be used for treatment. Most cavitary and protrusio defects can be treated with a cementless revision cup using screw fixation and grafting with morcellized bone. However, structural augmentation, custom components, or cage reconstruction may occasionally be necessary for managing larger defects with severe loss of acetabular bone stock.

  View details for PubMedID 24720308

• Maximizing function and outcomes in acetabular reconstruction: segmental bony defects and pelvic discontinuity. Instructional course lectures Pope, D., Blankenship, S., Jones, G., Robinson, B. S., Maloney, W. J., Paprosky, W. G., Ries, M. D., Saleh, K. J. 2014; 63: 187-197

  Abstract

  Acetabular reconstruction in revision total hip arthroplasty can be complicated by acetabular bone loss. In patients with severe acetabular bone deficiency with segmental bone defects or pelvic discontinuity, obtaining a stable, well-fixed acetabular component can be challenging. Although porous-coated, uncemented hemispheric cups can be used in most acetabular revisions, as the severity of acetabular deficiency increases, more complex alternatives are needed. Antiprotrusio cages have traditionally been used in the presence of acetabular columnar deficits, but higher failure rates and complications necessitated the development of alternative treatments. More recently, porous-coated acetabular augments have become an attractive alternative to structural allograft and oblong components when segmental bone loss is present. In the setting of severe bone loss or pelvic discontinuity, multiple reconstructive options are available. Depending on individual patient characteristics, plating of the pelvic discontinuity along with structural allografts, custom components, and modular or standard reconstructive cages can be used to obtain a stable acetabular component.

  View details for PubMedID 24720305

• Advances in acetabular osteolysis: biomarkers, imaging, and pharmacologic management. Instructional course lectures Illingworth, K. D., Wachter, N., Maloney, W. J., Paprosky, W. G., Ries, M. D., Saleh, K. J. 2014; 63: 177-186

  Abstract

  Acetabular osteolysis can be difficult to diagnose because patients often have no clinical symptoms even when there is substantial bone loss. Ideally, early detection would lead to early interventions. Imaging continues to be the frontline modality for the early detection of acetabular osteolysis. Although plain radiography is the current imaging modality most commonly used in routine follow-up examinations, its low sensitivity limits its usefulness. CT and MRI have proven to be better imaging modalities for the early detection of osteolysis; however, their use is limited by cost, radiation exposure, and time. Biomarkers hold promise for the early detection of osteolysis; however, their efficacy requires more rigorous research for validation. Early diagnosis and treatment of osteolysis may lead to better outcomes for patients.

  View details for PubMedID 24720304

• Stem cells catalyze cartilage formation by neonatal articular chondrocytes in 3D biomimetic hydrogels SCIENTIFIC REPORTS Lai, J. H., Kajiyama, G., Smith, R. L., Maloney, W., Yang, F. 2013; 3

  Abstract

  Cartilage loss is a leading cause of disability among adults and effective therapy remains elusive. Neonatal chondrocytes (NChons) are an attractive allogeneic cell source for cartilage repair, but their clinical translation has been hindered by scarce donor availability. Here we examine the potential for catalyzing cartilage tissue formation using a minimal number of NChons by co-culturing them with adipose-derived stem cells (ADSCs) in 3D hydrogels. Using three different co-culture models, we demonstrated that the effects of co-culture on cartilage tissue formation are dependent on the intercellular distance and cell distribution in 3D. Unexpectedly, increasing ADSC ratio in mixed co-culture led to increased synergy between NChons and ADSCs, and resulted in the formation of large neocartilage nodules. This work raises the potential of utilizing stem cells to catalyze tissue formation by neonatal chondrocytes via paracrine signaling, and highlights the importance of controlling cell distribution in 3D matrices to achieve optimal synergy.

  View details for DOI 10.1038/srep03553

  View details for Web of Science ID 000328623200007

  View details for PubMedID 24352100

• Effects of Heme Oxygenase-1 on Bacterial Antigen-Induced Articular Chondrocyte Catabolism In Vitro JOURNAL OF ORTHOPAEDIC RESEARCH Mawatari, T., Nakamichi, I., Suenaga, E., Maloney, W. J., Smith, R. L. 2013; 31 (12): 1943-1949

  Abstract

  This study tested the hypothesis that heme oxygenase-1 (HO-1) expression counteracts bacterial antigen-induced catabolic metabolism in human articular chondrocytes. HO-1 expression was induced in chondrocytes by the iron-containing porphoryin, hemin. Anti-catabolic and anti-apoptotic effects of HO-1 expression were evaluated following bacterial antigen (lipopolysaccharides, LPS) activation of chondrocytes by quantification of cytokine and cartilage matrix protein expression. Effects of HO-1 over-expression on chondrocyte matrix metabolism were evaluated using plasmid-driven protein synthesis. Hemin increased HO-1 expression and LPS increased interleukin-1beta and interleukin-6 gene and protein expression in chondrocytes. Hemin-induced HO-1 decreased LPS-induced interleukin-1beta and interleukin-6 gene and protein expression. Increased HO-1 expression partially reversed LPS-suppression of aggrecan and type II collagen gene expression and suppressed LPS-induced gene expression of IL-6, inducible nitric oxide synthase (iNOS), matrix metalloproteinases (MMPs), and IL-1beta. HO-1 induction was inversely correlated with LPS-induced chondrocyte apoptosis. HO-1 over-expression in chondrocytes decreased matrix protein gene expression. With LPS activation, increased HO-1 expression decreased chondrocyte catabolism, partially reversed LPS-dependent inhibition of cartilage matrix protein expression and protected against apoptosis. Without LPS, hemin-induced HO-1 and plasmid-based over-expression of HO-1 inhibited cartilage matrix gene expression. The results suggest that elevated HO-1 expression in chondrocytes is protective of cartilage in inflamed joints but may otherwise suppress matrix turn over.

  View details for DOI 10.1002/jor.22394

  View details for Web of Science ID 000325990300012

  View details for PubMedID 24038461

• Advances in Acetabular Reconstruction in Revision Total Hip Arthroplasty Maximizing Function and Outcomes After Treatment of Periacetabular Osteolysis Around the Well-Fixed Shell JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Hall, A., Eilers, M., Hansen, R., Robinson, B. S., Maloney, W. J., Paprosky, W. G., Ries, M. D., Saleh, K. J. 2013; 95A (18): 1710-1718

  View details for Web of Science ID 000326250400010

• The effect of rhBMP-2 and PRP delivery by biodegradable beta-tricalcium phosphate scaffolds on new bone formation in a non-through rabbit cranial defect model JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE Lim, H., Mercado-Pagan, A. E., Yun, K., Kang, S., Choi, T., Bishop, J., Koh, J., Maloney, W., Lee, K., Yang, Y. P., Park, S. 2013; 24 (8): 1895-1903

  Abstract

  This study evaluated whether the combination of biodegradable β-tricalcium phosphate (β-TCP) scaffolds with recombinant human bone morphogenetic protein-2 (rhBMP-2) or platelet-rich plasma (PRP) could accelerate bone formation and increase bone height using a rabbit non-through cranial bone defect model. Four non-through cylindrical bone defects with a diameter of 8-mm were surgically created on the cranium of rabbits. β-TCP scaffolds in the presence and absence of impregnated rhBMP-2 or PRP were placed into the defects. At 8 and 16 weeks after implantation, samples were dissected and fixed for analysis by microcomputed tomography and histology. Only defects with rhBMP-2 impregnated β-TCP scaffolds showed significantly enhanced bone formation compared to non-impregnated β-TCP scaffolds (P < 0.05). Although new bone was higher than adjacent bone at 8 weeks after implantation, vertical bone augmentation was not observed at 16 weeks after implantation, probably due to scaffold resorption occurring concurrently with new bone formation.

  View details for DOI 10.1007/s10856-013-4939-9

  View details for Web of Science ID 000321915300008

  View details for PubMedID 23779152

• Determinants of time to opioid cessation post-surgery Ruchelli, G., Clay, D., Schmidt, P., Humphreys, K., Trafton, J., Dirbas, F., Giori, N., Goodman, S., Hoang, C., Huddleston, J., Maloney, W., Merritt, R., Miller, M., Shrager, J., Whyte, R., Mackey, S., Carroll, I. CHURCHILL LIVINGSTONE. 2013: S18–S18

  View details for Web of Science ID 000317639400072

• Stem cells catalyze cartilage formation by neonatal articular chondrocytes in 3D biomimetic hydrogels. Scientific reports Lai, J. H., Kajiyama, G., Smith, R. L., Maloney, W., Yang, F. 2013; 3: 3553-?

  Abstract

  Cartilage loss is a leading cause of disability among adults and effective therapy remains elusive. Neonatal chondrocytes (NChons) are an attractive allogeneic cell source for cartilage repair, but their clinical translation has been hindered by scarce donor availability. Here we examine the potential for catalyzing cartilage tissue formation using a minimal number of NChons by co-culturing them with adipose-derived stem cells (ADSCs) in 3D hydrogels. Using three different co-culture models, we demonstrated that the effects of co-culture on cartilage tissue formation are dependent on the intercellular distance and cell distribution in 3D. Unexpectedly, increasing ADSC ratio in mixed co-culture led to increased synergy between NChons and ADSCs, and resulted in the formation of large neocartilage nodules. This work raises the potential of utilizing stem cells to catalyze tissue formation by neonatal chondrocytes via paracrine signaling, and highlights the importance of controlling cell distribution in 3D matrices to achieve optimal synergy.

  View details for DOI 10.1038/srep03553

  View details for PubMedID 24352100

• Is Routine Mid-term Total Hip Arthroplasty Surveillance Beneficial? CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Keeney, J. A., Ellison, B. S., Maloney, W. J., Clohisy, J. C. 2012; 470 (11): 3220-3226

  Abstract

  Routine followup of patients after primary or revision THA is commonly practiced and driven by concerns that delays in identifying early failure will result in more complicated or more costly surgical interventions. Although mid-term followup (4-10 years) has been performed to follow cohorts of patients, the benefit of observing individual patients regardless of symptoms has not been established.We determined (1) the reasons patients with THA return for mid-term followup, (2) the treatment recommendations and interventions occurring as a result of mid-term followup, and (3) how frequently revision surgery is recommended for asymptomatic and symptomatic patients at mid-term followup.We retrospectively identified 501 patients (503 hips) who returned for followup at least 4 years (mean, 5 years; range, 4-10.9 years) after their primary or revision THA. We recorded their reasons for followup and treatment recommendations, including those for revision surgery, at mid-term followup.Fifty-three percent of patients returning for routine followup had no symptoms, 31% reported an unrelated musculoskeletal concern, and 19% had symptoms from their primary THA (15%) or revision THA (32%). Sixty-nine percent of symptomatic patients and 10% of asymptomatic patients received treatment recommendations, with physical therapy as the most frequent intervention (74%). Revision surgery was recommended for 6% of symptomatic and 0.6% of asymptomatic patients.Although routine surveillance may identify rare, asymptomatic patients with arthroplasty failure, it is much more likely to result in recommendations for nonoperative management during early followup.Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-012-2411-7

  View details for Web of Science ID 000312368200036

  View details for PubMedID 22669552

• Advanced Age and Comorbidity Increase the Risk for Adverse Events After Revision Total Hip Arthroplasty JOURNAL OF ARTHROPLASTY Koenig, K., Huddleston, J. I., Huddleston, H., Maloney, W. J., Goodman, S. B. 2012; 27 (7): 1402-1407

  Abstract

  With the institution of quality-assurance parameters in health care, physicians must accurately measure and report the true baseline rates of adverse events (AEs) after complex surgical interventions. To better quantify the risk of AEs for revision total hip arthroplasty (THA), we divided a cohort of 306 patients (322 procedures) into age groups: group I (<65 years, n = 138), group II (65-79 years, n = 119), and group III (≥80 years, n = 65). Ninety-day rates of major AE were 9%, 19%, and 34% in the groups, respectively. Group III had an increased chance of experiencing major AE compared with groups I and II. Age and Charlson Comorbidity Index independently predicted major complications, whereas body mass index, sex, and type of revision did not.

  View details for DOI 10.1016/j.arth.2011.11.013

  View details for PubMedID 22245123

• Effect of Coadministration of Vancomycin and BMP-2 on Cocultured Staphylococcus aureus and W-20-17 Mouse Bone Marrow Stromal Cells In Vitro ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Nguyen, A. H., Kim, S., Maloney, W. J., Wenke, J. C., Yang, Y. 2012; 56 (7): 3776-3784

  Abstract

  In this study, we aimed to establish an in vitro bacterium/bone cell coculture model system and to use this model for dose dependence studies of dual administration of antibiotics and growth factors in vitro. We examined the effect of single or dual administration of the antibiotic vancomycin (VAN) at 0 to 16 μg/ml and bone morphogenetic protein-2 (BMP-2) at 0 or 100 ng/ml on both methicillin-sensitive Staphylococcus aureus and mouse bone marrow stromal cells (W-20-17) under both mono- and coculture conditions. Cell metabolic activity, Live/Dead staining, double-stranded DNA (dsDNA) amounts, and alkaline phosphatase activity were measured to assess cell viability, proliferation, and differentiation. An interleukin-6 (IL-6) enzyme-linked immunosorbent assay (ELISA) kit was used to test the bone cell inflammation response in the presence of bacteria. Our results suggest that, when delivered together in coculture, VAN and BMP-2 maintain their primary functions as an antibiotic and a growth factor, respectively. Most interestingly, this dual-delivery type of approach has shown itself to be effective at lower concentrations of VAN than those required for an approach relying strictly on the antibiotic. It may be that BMP-2 enhances cell proliferation and differentiation before the cells become infected. In coculture, a dosage of VAN higher than that used for treatment in monoculture may be necessary to effectively inhibit growth of Staphylococcus aureus. This could mean that the coculture environment may be limiting the efficacy of VAN, possibly by way of bacterial invasion of the bone cells. This report of a coculture study demonstrates a potential beneficial effect of the coadministration of antibiotics and growth factors compared to treatment with antibiotic alone.

  View details for DOI 10.1128/AAC.00114-12

  View details for Web of Science ID 000305673000042

  View details for PubMedID 22564844

  View details for PubMedCentralID PMC3393469

• Commentary: Is the hip bone connected to the spine bone? SPINE JOURNAL Huddleston, J. I., Maloney, W. J. 2012; 12 (5): 370-371

  Abstract

  COMMENTARY ON: Prather H, Van Dillen LR, Kymes SM, et al. Impact of coexistent lumbar spine disorders on clinical outcomes and physician charges associated with total hip arthroplasty. Spine J 2012;12:363-9 (in this issue).

  View details for DOI 10.1016/j.spinee.2012.05.002

  View details for Web of Science ID 000305298300002

  View details for PubMedID 22698149

• Age and Obesity Are Risk Factors for Adverse Events After Total Hip Arthroplasty Scientific Meeting of the Hip-Society / Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons Huddleston, J. I., Wang, Y., Uquillas, C., Herndon, J. H., Maloney, W. J. SPRINGER. 2012: 490–96

  Abstract

  Defining the epidemiology of adverse events after THA will aid in the development of strategies to enhance perioperative care.We identified (1) risk factors for adverse events in Medicare beneficiaries while hospitalized after THA and (2) trends in the rates of adverse events.Data were abstracted from medical records of 1809 Medicare beneficiaries who underwent THA from 2002 to 2007. We used the hierarchical generalized linear modeling approach to assess the odds of change in adverse events over time, the association of adverse events with outcomes, and the relationship of adverse events with patient characteristics by modeling the log-odds of adverse events as a function of demographic and clinical variables adjusted for year variable.The overall rate of adverse events was 5.8%; the 30-day mortality rate was 1.00%. Increased age, obesity, and year of procedure were risk factors for experiencing any adverse event. Annual rates of adverse events from 2002 to 2007 were 9.1%, 8.2%, 4.9%, 4.1%, 3.5%, and 3.0%, respectively. Experiencing any adverse event was associated with an increased length of stay and an increased chance of readmission but not with an increased chance of mortality. The annual rate of all adverse events decreased from 2002-2004 to 2005-2007 (odds ratio = 0.83; 95% confidence interval, 0.74-0.92).Older and obese patients should be counseled regarding their increased risk for the development of adverse events after THA. The cause of the decline in the rate of adverse events between two time periods is unclear and warrants further investigation to confirm and identify the cause.

  View details for DOI 10.1007/s11999-011-1967-y

  View details for Web of Science ID 000299056000022

  View details for PubMedID 21796477

  View details for PubMedCentralID PMC3254770

• Decreased Length of Stay After TKA Is Not Associated With Increased Readmission Rates in a National Medicare Sample CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Vorhies, J. S., Wang, Y., Herndon, J. H., Maloney, W. J., Huddleston, J. I. 2012; 470 (1): 166-171

  Abstract

  There is a trend toward decreasing length of hospital stay (LOS) after TKA although it is unclear whether this trend is detrimental to the overall postoperative course. Such information is important for future decisions related to cost containment.We determined whether decreases in LOS after TKA are associated with increases in readmission rates.We retrospectively reviewed the rates and reasons for readmission and LOS for 4057 Medicare TKA patients from 2002 to 2007. We abstracted data from the Medicare Patient Safety Monitoring System. Hierarchical generalized linear modeling was used to assess the odds of changing readmission rates and LOS over time, controlling for changes in patient demographic and clinical variables.The overall readmission rate in the 30 days after discharge was 228/4057 (5.6%). The 10 most common reasons for readmission were congestive heart failure (20.4%), chronic ischemic heart disease (13.9%), cardiac dysrhythmias (12.5%), pneumonia (10.8%), osteoarthrosis (9.4%), general symptoms (7.4%), acute myocardial infarction (7.0%), care involving other specified rehabilitation procedure (6.3%), diabetes mellitus (6.3%), and disorders of fluid, electrolyte, and acid-base balance (5.9%); the top 10 causes did not include venous thromboembolism syndromes. We found no difference in the readmission rate between the periods 2002-2004 (5.5%) and 2005-2007 (5.8%) but a reduction in LOS between the periods 2002-2004 (4.1 ± 2.0 days) and 2005-2007 (3.8 ± 1.7 days).The most common causes for readmission were cardiac-related. A reduction in LOS was not associated with an increase in the readmission rate in this sample. Optimization of cardiac status before discharge and routine primary care physician followup may lead to lower readmission rates.

  View details for DOI 10.1007/s11999-011-1957-0

  View details for Web of Science ID 000298103100021

  View details for PubMedID 21720934

  View details for PubMedCentralID PMC3237965

• Human bone marrow hematopoietic stem cells are increased in frequency and myeloid-biased with age PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Pang, W. W., Price, E. A., Sahoo, D., Beerman, I., Maloney, W. J., Rossi, D. J., Schrier, S. L., Weissman, I. L. 2011; 108 (50): 20012-20017

  Abstract

  In the human hematopoietic system, aging is associated with decreased bone marrow cellularity, decreased adaptive immune system function, and increased incidence of anemia and other hematological disorders and malignancies. Recent studies in mice suggest that changes within the hematopoietic stem cell (HSC) population during aging contribute significantly to the manifestation of these age-associated hematopoietic pathologies. Though the mouse HSC population has been shown to change both quantitatively and functionally with age, changes in the human HSC and progenitor cell populations during aging have been incompletely characterized. To elucidate the properties of an aged human hematopoietic system that may predispose to age-associated hematopoietic dysfunction, we evaluated immunophenotypic HSC and other hematopoietic progenitor populations from healthy, hematologically normal young and elderly human bone marrow samples. We found that aged immunophenotypic human HSC increase in frequency, are less quiescent, and exhibit myeloid-biased differentiation potential compared with young HSC. Gene expression profiling revealed that aged immunophenotypic human HSC transcriptionally up-regulate genes associated with cell cycle, myeloid lineage specification, and myeloid malignancies. These age-associated alterations in the frequency, developmental potential, and gene expression profile of human HSC are similar to those changes observed in mouse HSC, suggesting that hematopoietic aging is an evolutionarily conserved process.

  View details for DOI 10.1073/pnas.1116110108

  View details for Web of Science ID 000298034800040

  View details for PubMedID 22123971

  View details for PubMedCentralID PMC3250139

• Readmission and Length of Stay After Total Hip Arthroplasty in a National Medicare Sample JOURNAL OF ARTHROPLASTY Vorhies, J. S., Wang, Y., Herndon, J., Maloney, W., Huddleston, J. I. 2011; 26 (6): 119-123

  Abstract

  Evaluation of hospital readmissions after total hip arthroplasty may help improve patient safety and cost reduction. This study investigates the rates and reasons for readmission as well as length of hospital stay (LOS) for 1802 total hip arthroplasty patients from 2002 to 2007. Data were abstracted from the Medicare Patient Safety Monitoring System. The overall 30-day rate of readmission was 6.8%. There was no difference in readmission rate from 2002 to 2004 (7.1%) to 2005 to 2007 (6.3%) (odds ratio, 0.90; 95% confidence interval, 0.63-1.30; P = .58). The overall mean LOS was 4.2 ± 2.2 days. There was a significant reduction in LOS from 2002 to 2004 (4.4 ± 2.5 days) to 2005 to 2007 (3.8 ± 1.7 days) (odds ratio, 1.28; 95% confidence interval, 1.25-1.31; P < .0001). The most common causes for readmission were cardiac related. A reduction in LOS was not associated with an increase in the rate of readmission in this sample. Efforts to optimize cardiac status before discharge may lead to lower rates of readmission in the future.

  View details for DOI 10.1016/j.arth.2011.04.036

  View details for Web of Science ID 000294393000023

  View details for PubMedID 21723700

• Effects of Intermittent Hydrostatic Pressure and BMP-2 on Osteoarthritic Human Chondrocyte Metabolism In Vitro JOURNAL OF ORTHOPAEDIC RESEARCH Smith, R. L., Lindsey, D. P., Dhulipala, L., Harris, A. H., Goodman, S. B., Maloney, W. J. 2011; 29 (3): 361-368

  Abstract

  This study examined effects of intermittent hydrostatic pressure (IHP) and a chondrogenic growth factor, bone morphogenetic protein-2 (BMP-2), on anabolic, catabolic, and other metabolic markers in human osteoarthritic (OA) chondrocytes in vitro.Articular chondrocytes, isolated from femoral OA cartilage and maintained in high-density monolayer culture, were examined for effects of BMP-2 and IHP on gene expression of matrix-associated proteins (aggrecan, type II collagen, and SOX9) and catabolic matrix metalloproteinases (MMP-2 and MMP-3) and culture medium levels of the metabolic markers MMP-2, nitric oxide (NO), and glycosaminoglycan (GAG). The results were analyzed using a mixed linear regression model to investigate the effects of load and growth factor concentration.IHP and BMP-2 modulated OA chondrocyte metabolism in accordance with growth factor concentration independently, without evidence of synergism or antagonism. Each type of stimulus acted independently on anabolic matrix gene expression. Type II collagen and SOX9 gene expression were stimulated by both IHP and BMP-2 whereas aggrecan was increased only by BMP-2. IHP exhibited a trend to decrease MMP-2 gene expression as a catabolic marker whereas BMP-2 did not. NO production was increased by addition of BMP-2 and IHP exhibited a trend for increased levels. GAG production was increased by BMP-2.This study confirmed the hypothesis that human OA chondrocytes respond to a specific type of mechanical load, IHP, through enhanced articular cartilage macromolecule gene expression and that IHP, in combination with a chondrogenic growth factor BMP-2, additively enhanced matrix gene expression without interactive effects.

  View details for DOI 10.1002/jor.21250

  View details for Web of Science ID 000287173500009

  View details for PubMedID 20882590

• Large Acetabular Defects Can be Managed with Cementless Revision Components 77th Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons (AAOS) Paxton, E. S., Keeney, J. A., Maloney, W. J., Clohisy, J. C. SPRINGER. 2011: 483–93

  Abstract

  Optimal techniques for acetabular revision in the setting of major pelvic osteolysis have not been established. Bilobed components, structural grafts, and reinforcement cages have demonstrated 10-24% midterm failure rates. While cementless hemispherical components have been utilized to treat large acetabular defects, most reports have not focused specifically on patients with extensive deficiencies.We report midterm clinical scores, component revisions, and complications following focal bone grafting and cementless acetabular revision in cases with major periacetabular osteolysis.We identified 30 patients (32 hips) who underwent cementless acetabular revision to treat massive acetabular bone loss at an average followup of 53 months. We excluded three patients lost to followup and two patients who died prior to minimum 24 month followup. Harris Hip Scores were assessed before and after surgery. Postoperative radiographs were evaluated for graft incorporation and component migration. Component revision and component migration are reported as failures.Mean Harris Hip Score improved from 52.5 (range, 17.7-90.7) to 87.3 (range, 25.3-100) points. Three hips (9%) were revised for aseptic loosening. Three components (10.7%) demonstrated radiographic migration, but were not revised. Complete graft incorporation was seen in 17 cases (68%). There were five major complications (14%).Cementless acetabular fixation and bone grafting result in clinical scores and survivorship comparable to other options at midterm followup, with potential for biological fixation.Level IV, clinical research study. See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-010-1563-6

  View details for Web of Science ID 000286939300024

  View details for PubMedID 20922585

• The Incidence of Acetabular Osteolysis in Young Patients With Conventional versus Highly Crosslinked Polyethylene 77th Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons (AAOS) Mall, N. A., Nunley, R. M., Zhu, J. J., Maloney, W. J., Barrack, R. L., Clohisy, J. C. SPRINGER. 2011: 372–81

  Abstract

  Osteolysis is a major mode of hip implant failure. Previous literature has focused on the amount of polyethylene wear comparing highly crosslinked polyethylene (HXPLE) with conventional liners but has not clarified the relative incidence of osteolysis with these two liners.We determined (1) the incidence of osteolysis in HXLPE versus conventional polyethylene (CPE), (2) the ability to detect and evaluate the size of lytic lesions using radiographs compared with CT scans, (3) head penetration in hips without and with lysis, and (4) determined whether acetabular position, head size, and UCLA activity score contributed to lysis.We compared head penetration and osteolysis on plain radiographs and presence and volume of osteolysis on CT scans in 48 patients with HXLPE (mean, 46.5 years) and 50 patients with CPE (mean, 43.2 years). The minimum followup was 5 years (average, 7.2 years; range, 5.1-10.9 years),Osteolysis was apparent on CT in a larger number of patients with CPE liners than HXLPE liners: 12 of 50 (24%) versus one of 48 (2%), respectively. We found no correlation between head penetration and volume of osteolytic lesions. Head penetration was greater in patients with osteolysis. Smaller head sizes were associated with greater wear and those with osteolysis had smaller head sizes; however, there was no difference in acetabular component position or UCLA activity in those with lysis compared with those without.HXLPE diminished the incidence of osteolysis, but the lack of correlation between penetration and volume of osteolysis suggests other factors other than wear contribute to the development of osteolysis.Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-010-1518-y

  View details for Web of Science ID 000286939300008

  View details for PubMedID 20824407

  View details for PubMedCentralID PMC3018187

• Liner Exchange and Bone Grafting Rare Option to Treat Wear & Lysis of Stable TKAs Annual Scientific Meeting of the Knee-Society Callaghan, J. J., Reynolds, E. R., Ting, N. T., Goetz, D. D., Clohisy, J. C., Maloney, W. J. SPRINGER. 2011: 154–59

  Abstract

  Liner exchange and bone grafting are commonly performed for wear and osteolysis around well-fixed modular acetabular components that otherwise would require structural allografting and revision THA. However, liner exchange in the face of substantial lysis around TKA has been performed rarely with reports of failure rates of up to 25% at 3 year followup.We therefore evaluated the technique of liner exchange and bone grafting for cases of wear and extensive osteolysis around TKAs in which the components were well-fixed and well-aligned to determine (1) rerevision rates; (2) fate of the bone graft; (3) radiographic loosening rates; and (4) functional scores.We retrospectively reviewed 22 patients (25 knees) who underwent revision TKA with exchange of the modular polyethylene insert and bone grafting in cases with well-fixed components and large areas of osteolysis (up to 54 cm(2) on a single projection) at the time of revision. The average area of osteolysis was 21 cm(2) and 10 cm(2) on the AP projection of the femur and tibia, respectively. On the lateral projection, the average area of osteolysis for the femur and tibia was 22 cm(2) and 9.3 cm(2). Minimum clinical and radiographic followup was 22 and 22 months (average, 61 and 59; range, 22-142 and 22-130, respectively).One of the 25 knees was revised for aseptic loosening or recurrence of osteolysis. On radiographs, 84.6% and 70% of femoral and tibial osteolytic lesions, respectively, showed evidence of complete or near complete graft incorporation. The remaining lesions showed evidence of partial graft incorporation with the exception of one tibial lesion, which was in the revised case. All other components were well fixed with no evidence of radiographic loosening.In this selected series of cases with extensive osteolysis around well-fixed and well-aligned TKAs, liner exchange and bone grafting provided durable midterm results with extensive graft incorporation.Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-010-1521-3

  View details for Web of Science ID 000286938400023

  View details for PubMedID 20809171

• Use and Cost-Effectiveness of Intraoperative Acid-Fast Bacilli and Fungal Cultures in Assessing Infection of Joint Arthroplasties JOURNAL OF ARTHROPLASTY Wadey, V. M., Huddleston, J. I., Goodman, S. B., Schurman, D. J., Maloney, W. J., Baron, E. J. 2010; 25 (8): 1231-1234

  Abstract

  The objective of this study is to determine a protocol for collecting acid-fast bacilli (AFB) and fungal intraoperative cultures during orthopedic procedures. An observational study was undertaken. Four hundred forty-six AFB cultures and 486 fungal cultures were processed over a 2-year period. The number of positive cultures was determined. A protocol specific to handling these types of specimens was developed. Cost analysis was completed to determine both the time and money saved if the new protocol was implemented. The infrequency of positive AFB and fungal cultures in this study suggests that it is only necessary to routinely request AFB and fungal cultures on 1 of 5 samples. Implementation of this protocol has potential to lead to substantial cost reduction and resource savings without diminishing patient outcomes.

  View details for DOI 10.1016/j.arth.2009.08.018

  View details for Web of Science ID 000284749500009

  View details for PubMedID 19879728

• The Fate of Grafting Acetabular Defects During Revision Total Hip Arthroplasty Closed Meeting of the International-Hip-Society Mall, N. A., Nunley, R. M., Smith, K. E., Maloney, W. J., Clohisy, J. C., Barrack, R. L. SPRINGER. 2010: 3286–94

  Abstract

  Acetabular defects are frequently grafted during revision THA. Previous studies using plain radiographs report high rates of graft incorporation. However, given plain radiographs underestimate osteolysis, it is unclear whether plain radiographs adequately reflect graft fill or incorporation.We determined if (1) graft fill; or (2) incorporation (measured as graft-bone contact) differed with complete revision and grafting compared to liner exchange and grafting; (3) defect fill and incorporation could be assessed on plain radiographs; and (4) the cost of bone grafting differed with these two procedures.We identified 40 patients who underwent revision THA for aseptic loosening or polyethylene wear and osteolysis, either with retention of a well-fixed cup or complete acetabular revision in which bone graft was used. Lesion size, percent fill, and graft healing was quantified from CT scans. A limited cost analysis was performed using the current hospital costs for implants, bone grafts, and bone graft substitutes. The minimum followup was 1 year (mean, 4.8 years; range, 1-11 years).The average defect fill was 30% (range, 0%-81%). The average percent of healing to host bone was 24% (range, 0-66%). Complete revisions had a higher percent defect fill compared to head/liner changes (47% versus 17%) as well as a higher degree of graft healing to host bone compared to head/liner changes (36% versus 14%). High resolution CT demonstrated lower percentages of defect fill and graft healing than previous reports based on plain radiographs. Bone grafting costs exceeded implant costs in the head/liner exchange group; however, the overall cost was higher in the complete revision group.Higher degrees of defect fill and healing were seen with complete revisions compared to head/liner exchanges. Compared to CT scans, plain radiograph assessment tended to overestimate defect fill and healing.

  View details for DOI 10.1007/s11999-010-1427-0

  View details for Web of Science ID 000288440700021

  View details for PubMedID 20577842

• Stem cells and the aging hematopoietic system CURRENT OPINION IN IMMUNOLOGY Beerman, I., Maloney, W. J., Weissmann, I. L., Rossi, D. J. 2010; 22 (4): 500-506

  Abstract

  Advancing age is accompanied by a number of clinically significant conditions arising in the hematopoietic system that include: diminution and decreased competence of the adaptive immune system, elevated incidence of certain autoimmune diseases, increased hematological malignancies, and elevated incidence of age-associated anemia. As with most tissues, the aged hematopoietic system also exhibits a reduced capacity to regenerate and return to normal homeostasis after injury or stress. Evidence suggests age-dependent functional alterations within the hematopoietic stem cell compartment significantly contribute to many of these pathophysiologies. Recent developments have shed light on how aging of the hematopoietic stem cell compartment contributes to hematopoietic decline through diverse mechanisms.

  View details for DOI 10.1016/j.coi.2010.06.007

  View details for Web of Science ID 000281462800013

  View details for PubMedID 20650622

• Effects of Tensile Strain and Fluid Flow on Osteoarthritic Human Chondrocyte Metabolism In Vitro JOURNAL OF ORTHOPAEDIC RESEARCH Mawatari, T., Lindsey, D. P., Harris, A. H., Goodman, S. B., Maloney, W. J., Smith, R. L. 2010; 28 (7): 907-913

  Abstract

  This study examined the hypothesis that tensile strain and fluid flow differentially influence osteoarthritic human chondrocyte metabolism. Primary high-density monolayer chondrocytes cultures were exposed to varying magnitudes of tensile strain and fluid-flow using a four-point bending system. Metabolic changes were quantified by real-time PCR measurement of aggrecan, IL-6, SOX-9, and type II collagen gene expression, and by determination of nitric oxide levels in the culture medium. A linear regression model was used to investigate the roles of strain, fluid flow, and their interaction on metabolic activity. Aggrecan, type II collagen, and SOX9 mRNA expression were negatively correlated to increases in applied strain and fluid flow. An effect of the strain on the induction of nitric oxide release and IL-6 gene expression varied by level of fluid flow (and visa versa). This interaction between strain and fluid flow was negative for nitric oxide and positive for IL-6. These results confirm that articular chondrocyte metabolism is responsive to tensile strain and fluid flow under in vitro loading conditions. Although the articular chondrocytes reacted to the mechanically applied stress, it was notable that there was a differential effect of tensile strain and fluid flow on anabolic and catabolic markers.

  View details for DOI 10.1002/jor.21085

  View details for PubMedID 20063382

• In Vivo Femoral Head Damage and Its Effect on Polyethylene Wear JOURNAL OF ARTHROPLASTY Ito, H., Maloney, C. M., Crowninshield, R. D., Clohisy, J. C., McDonald, D. J., Maloney, W. J. 2010; 25 (2): 302-308

  Abstract

  The purposes of this study were to determine the spectrum of femoral head damage in patients undergoing revision total hip arthroplasty and to determine the impact of that damage on polyethylene wear. One hundred eight consecutive modular metal femoral heads were retrieved at revision surgery. The mean roughness (Ra) value was 0.18 +/- 0.18 microm. The roughest femoral heads (mean Ra, 0.56 microm) were from retrievals correlated with mode 2 wear (recurrent dislocation and complete wear through of the polyethylene liner). Five million cycles of wear tests were performed using retrieved femoral heads against both new conventional and highly cross-linked polyethylene. The mean wear rate of conventional polyethylene was 15.9 +/- 4.3 mg and that of highly cross-linked polyethylene was 0.04 +/- 0.14 mg per 1 million cycles (P < .001). Highly cross-linked polyethylene was more resistant to wear than conventional polyethylene, even when mated against roughened femoral heads.

  View details for DOI 10.1016/j.arth.2009.01.010

  View details for Web of Science ID 000277580900023

  View details for PubMedID 19201153

• Iliopsoas Bursa Injections Can be Beneficial for Pain after Total Hip Arthroplasty Annual Symposium of the Hip-Society Nunley, R. M., Wilson, J. M., Gilula, L., Clohisy, J. C., Barrack, R. L., Maloney, W. J. SPRINGER. 2010: 519–26

  Abstract

  Impingement of the iliopsoas tendon is an uncommon cause of groin pain after total hip arthroplasty (THA). We asked whether selective steroid and anesthetic injections for iliopsoas tendonitis after THA would relieve pain and improve function. We retrospectively reviewed 27 patients with presumed iliopsoas tendinitis treated by fluoroscopically guided injections of the iliopsoas bursa. Pre- and immediately postinjection, questionnaires and telephone followup questionnaires were administered to determine patient outcomes. Four patients were lost to followup and we were unable to obtain information from relatives on an additional four; the questionnaire was administered to the remaining 19 patients, including six who subsequently had surgery at an average of 44.6 months (range, 25-68 months) after their first injection. The average modified Harris hip score in the 19 patients improved from 61 preinjection to 82 postinjection and the average pain improved from 6.4 preinjection to 2.9 postinjection, but eight patients (30%) required a second injection at an average of 8.2 months after the first injection. Ultimately, six patients (22%) had an additional surgical procedure to address the underlying cause of the iliopsoas irritation. Iliopsoas tendonitis is uncommon after THA but should be considered in the differential diagnosis of all patients who present with groin pain after THA. Selective steroid and anesthetic injections of the iliopsoas bursa give adequate pain relief in the majority of patients and should be considered part of the nonoperative treatment plan before surgical release of the iliopsoas tendon or component revision.Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-009-1141-y

  View details for Web of Science ID 000274764400032

  View details for PubMedID 19851816

• Adverse Events After Total Knee Arthroplasty A National Medicare Study JOURNAL OF ARTHROPLASTY Huddleston, J. I., Maloney, W. J., Wang, Y., Verzier, N., Hunt, D. R., Herndon, J. H. 2009; 24 (6): 95-100

  Abstract

  Adverse events from 2033 total knee arthroplasty patients were documented by nonphysician abstractors. The annual rate of adverse events from 2002 to 2004 was 9.2%, 6.4%, and 5.8%, respectively. Congestive heart failure (odds ratio, 2.1; 95% confidence interval, 1.2-3.5; P < .01) and chronic obstructive pulmonary disease (odds ratio, 1.8; 95% confidence interval, 1.2-2.7; P < .01) were associated with a significantly increased risk of experiencing any adverse event during the index hospitalization. The 30-day postprocedure rate of readmission for all causes was 5.5%. Experiencing an adverse event during the index hospitalization increased the length of stay (P < .001). The rate of symptomatic venous thromboembolism 30 days postprocedure was 1.7%. The 30-day postprocedure mortality rate was 0.3%. Experiencing any adverse event was associated with an increased 30-day postprocedure mortality (P < .001). Compared with previous studies of Medicare claims, these data reveal a substantial decrease in the mortality rate, an increased readmission rate, and no substantial change in the rate of venous thromboembolism.

  View details for DOI 10.1016/j.arth.2009.05.001

  View details for Web of Science ID 000269607800020

  View details for PubMedID 19577884

• THA with Highly Cross-linked Polyethylene in Patients 50 Years or Younger CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Shia, D. S., Clohisy, J. C., Schinsky, M. F., Martell, J. M., Maloney, W. J. 2009; 467 (8): 2059-2065

  Abstract

  Highly cross-linked polyethylene has been associated with low in vitro wear, but also has decreased in vitro ultimate yield strength. We therefore asked whether highly cross-linked polyethylene would result in lower outcome scores, wear, or early failure in a young patient population. Seventy THAs in 64 patients were performed using a highly cross-linked (electron beam-irradiated to 9 Mrads) acetabular liner and a cobalt-chrome femoral head. The average age of the patients at surgery was 41 years (range, 19-50 years). The minimum followup was 2.4 years (average, 4 years; range, 2.4-6.5 years). We recorded demographic and clinical data, including Harris hip score. Polyethylene wear measurements were analyzed with a validated, computer-assisted, edge detection method. The average Harris hip score improved from 53 to 92 at last followup. There was no evidence of acetabular or femoral loss of fixation, subsidence, or loosening. Linear wear was undetectable at this followup interval. No patient experienced catastrophic failure or underwent revision surgery. These data show low polyethylene wear rates and no catastrophic failures at early followup in a young patient cohort.Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-008-0697-2

  View details for Web of Science ID 000267779100019

  View details for PubMedID 19142685

• Minimal Incision Surgery as a Risk Factor for Early Failure of Total Knee Arthroplasty JOURNAL OF ARTHROPLASTY Barrack, R. L., Barnes, C. L., Burnett, R. S., Miller, D., Clohisy, J. C., Maloney, W. J. 2009; 24 (4): 489-498

  Abstract

  A consecutive series of revision total knee arthroplasty (TKA) performed at 3 centers by 5 surgeons for a 3-year period was reviewed. Revisions performed for infection and rerevisions were excluded. Review of clinical and radiographic data determined incision type, sex, age, time to revision, and primary diagnosis at time of revision. Two-hundred thirty-seven first-time revision TKAs were performed, of which 44 (18.6%) had been a minimal incision surgery (MIS) primary TKA and 193 (81.4%) had been a standard primary TKA. Patients with MIS were younger (62.1 vs 66.2 years, P = .02). Most striking was the difference in time to revision, which was significantly shorter for the MIS group (14.8 vs 80 months, P < .001). Minimal incision surgery TKA accounted for a substantial percentage of revision TKA in recent years at these centers. The high prevalence of MIS failures occurring within 24 months is disturbing and warrants further investigation.

  View details for DOI 10.1016/j.arth.2009.02.004

  View details for Web of Science ID 000266846500001

  View details for PubMedID 19339153

• Meniscal root injury and spontaneous osteonecrosis of the knee: an observation. journal of bone and joint surgery. British volume Robertson, D. D., Armfield, D. R., Towers, J. D., Irrgang, J. J., Maloney, W. J., Harner, C. D. 2009; 91 (2): 190-195

  Abstract

  We describe injuries to the posterior root of the medial meniscus in patients with spontaneous osteonecrosis of the medial compartment of the knee. We identified 30 consecutive patients with spontaneous osteonecrosis of the medial femoral condyle. The radiographs and MR imaging were reviewed. We found tears of the posterior root of the medial meniscus in 24 patients (80%). Of these, 15 were complete and nine were partial. Complete tears were associated with > 3 mm of meniscal extrusion. Neither the presence of a root tear nor the volume of the osteonecrotic lesion were associated with age, body mass index (BMI), gender, side affected, or knee alignment. The grade of osteoarthritis was associated with BMI. Although tears of the posterior root of the medial meniscus were frequently present in patients with spontaneous osteonecrosis of the knee, this does not prove cause and effect. Further study is warranted.

  View details for DOI 10.1302/0301-620X.91B2.21097

  View details for PubMedID 19190052

• Meniscal root injury and spontaneous osteonecrosis of the knee AN OBSERVATION JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Robertson, D. D., Armfield, D. R., Towers, J. D., Irrgang, J. J., Maloney, W. J., Harner, C. D. 2009; 91B (2): 190-195

  View details for DOI 10.1302/0301-620X.91B2.21097

  View details for Web of Science ID 000263073300010

• Revision total knee arthroplasty for major osteolysis. The Iowa orthopaedic journal Burnett, R. S., Keeney, J. A., Maloney, W. J., Clohisy, J. C. 2009; 29: 28-37

  Abstract

  Twenty-eight knees in 26 patients underwent revision TKA requiring surgical management of major osteolytic defects. Three groups of osteolytic defects were identified based upon the degree of implant stability and the magnitude of bone loss. Outcome measures included the Knee Society Clinical Rating Score (KSCRS), visual analog pain score, and radiographs. At a mean follow-up of 48 months, the average knee pain scores, range of motion, and KSCRS improved (p<.05). Ninety-six percent of the knees demonstrated clinical and functional improvement. Radiographs for 24 revision TKA's (86 percent) demonstrated component stability and incorporation of both cancellous and structural allografts. Revision TKA for major osteolytic defects may be effectively performed using a variety of bone grafting techniques. Both morselized and structural bone grafting, in combination with stemmed components was successful in managing revision TKA in the setting of major osteolysis. Significant improvement in clinical and radiographic outcomes may be anticipated using these surgical techniques.

  View details for PubMedID 19742082

• Averaging different alignment axes improves femoral rotational alignment in computer-navigated total knee arthroplasty. journal of bone and joint surgery. American volume Siston, R. A., Cromie, M. J., Gold, G. E., Goodman, S. B., Delp, S. L., Maloney, W. J., Giori, N. J. 2008; 90 (10): 2098-2104

  Abstract

  Computer navigation systems generally establish the rotational alignment axis of the femoral component on the basis of user-defined anatomic landmarks. However, navigation systems can also record knee kinematics and average alignment axes established with multiple techniques. We hypothesized that establishing femoral rotational alignment with the use of kinematic techniques is more accurate and precise (repeatable) than the use of anatomic techniques and that establishing femoral rotational alignment by averaging the results of different alignment techniques is more accurate and precise than the use of a single technique.Twelve orthopaedic surgeons used three anatomic and two kinematic alignment techniques to establish femoral rotational alignment axes in a series of nine cadaver knees. The axes derived with the individual anatomic and kinematic techniques as well as the axes derived with six combination techniques--i.e., those involving averaging of the alignments established with two of the individual techniques--were compared against a reference axis established with computed tomography images of each femur.The kinematic methods were not more accurate (did not have smaller mean errors) or more precise (repeatable) than the anatomic techniques. The combination techniques were accurate (five of the six had a mean error of <5 degrees ) and significantly more precise than all but one of the single methods. The percentage of measurements with <5 degrees of error as compared with the reference epicondylar axis was 37% for the individual anatomic techniques, 30% for the individual kinematic techniques, and 58% for the combination techniques.Averaging the results of kinematic and anatomic techniques, which is possible with computer navigation systems, appears to improve the accuracy of rotational alignment of the femoral component. The number of rotational alignment outliers was reduced when combination techniques were used; however, they are still a problem and continued improvement in methods to accurately establish rotation of the femoral component in total knee arthroplasty is needed.

  View details for DOI 10.2106/JBJS.G.00996

  View details for PubMedID 18829906

• Averaging Different Alignment Axes Improves Femoral Rotational Alignment in Computer-Navigated Total Knee Arthroplasty JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Siston, R. A., Cromie, M. J., Gold, G. E., Goodman, S. B., Delp, S. L., Maloney, W. J., Giori, N. J. 2008; 90A (10): 2098-2104

  Abstract

  Computer navigation systems generally establish the rotational alignment axis of the femoral component on the basis of user-defined anatomic landmarks. However, navigation systems can also record knee kinematics and average alignment axes established with multiple techniques. We hypothesized that establishing femoral rotational alignment with the use of kinematic techniques is more accurate and precise (repeatable) than the use of anatomic techniques and that establishing femoral rotational alignment by averaging the results of different alignment techniques is more accurate and precise than the use of a single technique.Twelve orthopaedic surgeons used three anatomic and two kinematic alignment techniques to establish femoral rotational alignment axes in a series of nine cadaver knees. The axes derived with the individual anatomic and kinematic techniques as well as the axes derived with six combination techniques--i.e., those involving averaging of the alignments established with two of the individual techniques--were compared against a reference axis established with computed tomography images of each femur.The kinematic methods were not more accurate (did not have smaller mean errors) or more precise (repeatable) than the anatomic techniques. The combination techniques were accurate (five of the six had a mean error of <5 degrees ) and significantly more precise than all but one of the single methods. The percentage of measurements with <5 degrees of error as compared with the reference epicondylar axis was 37% for the individual anatomic techniques, 30% for the individual kinematic techniques, and 58% for the combination techniques.Averaging the results of kinematic and anatomic techniques, which is possible with computer navigation systems, appears to improve the accuracy of rotational alignment of the femoral component. The number of rotational alignment outliers was reduced when combination techniques were used; however, they are still a problem and continued improvement in methods to accurately establish rotation of the femoral component in total knee arthroplasty is needed.

  View details for DOI 10.2106/JBJS.G.00996

  View details for Web of Science ID 000259873300006

• Implementation of the American Society of Anesthesiologists Physical Status classification system in periodontal practice JOURNAL OF PERIODONTOLOGY Maloney, W. J., Weinberg, M. A. 2008; 79 (7): 1124-1126

  Abstract

  The American Society of Anesthesiologists Physical Status (ASA-PS) classification is a preoperative rating given to each patient by an anesthesia provider with the sole purpose of assessing the physical state of the patient before anesthesia is administered. It was designed originally as a standardized way for dentists and physicians to convey information about the patient's overall health status and allow outcomes to be stratified by a global assessment of their severity of illness. However, in practice, the ASA-PS classification is often misused as a measure of operative risk, which is the basis of much criticism. Modification of periodontal treatment may be necessary in certain medically complex patients. The ASA-PS classification serves an integral part of risk assessment in determining how a patient should be managed by the periodontist. It should be incorporated into all periodontal practices. Medical assessment of patients has become an essential part of dentistry, as even the most common medical problems may require modifications to routine periodontal care. Periodontists must assess and manage patients for underlying medical conditions and are required to provide dental care to a diversity of medically complex patients. Today many patients in a periodontal practice have multiple medical conditions and are taking many medications. It is more difficult to manage these types of patients, and proper assessment of their physical status is an important part of clinical practice. The ASA-PS classification system is a valuable assessment tool that subjectively categorizes patients into subgroups by preoperative physical fitness prior to administering anesthesia.

  View details for DOI 10.1902/jop.2008.070625

  View details for Web of Science ID 000257643600002

  View details for PubMedID 18597592

• Orthopedic surgery core curriculum hip and knee reconstruction 73rd Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons Wadey, V. M., Maloney, W. J., Dev, P., Walker, D. CMA-CANADIAN MEDICAL ASSOC. 2008: 135–41

  Abstract

  To develop a core curriculum for orthopedic surgery and to conduct a national survey to assess the importance of 281 curriculum items. Attention was focused on 55 topics pertaining to hip and knee reconstruction.A 281-item curriculum was developed. We completed a content review and cross-sectional survey of a random selection of orthopedic surgeons whose primary affiliation was nonuniversity. We analyzed the data descriptively and quantitatively, using histograms, a modified Hotelling's T2 statistic with the p value determined by a permutation test, and the Benjamini- Hochberg/Yekutieli procedure. Our analyses assumed that each respondent answered questions independently of the answers of any other respondent but that the answers to different questions by the same respondent might be dependent.Of 156 orthopedic surgeons, 131 (84%) participated in this study. Of 55 items ranked by all respondents, 42 received an average mean score greater than 3.5/4.0, and 51 received an average mean score equal to or greater than 3.0/40 (the standard deviation for each item ranged from 0.00 to 0.08), suggesting that 92.7% of the items are important or probably important to know by the end of residency.This study demonstrates agreement that it is important to include 92.7% of the items that pertain to hip and knee reconstruction in a core curriculum for orthopedic surgery. Residency training programs may need to ensure that appropriate educational opportunities focusing on complex primary and revision surgery are available to meet the future needs of orthopedic surgeons whose primary affiliation is nonuniversity.

  View details for Web of Science ID 000254552400010

  View details for PubMedID 18377755

• Highly cross-linked polyethylene bearing surfaces in total hip arthroplasty. Journal of surgical orthopaedic advances Atienza, C., Maloney, W. J. 2008; 17 (1): 27-33

  Abstract

  Polyethylene wear-induced osteolysis is the most significant primary factor limiting the life span of total joint arthroplasty. To reduce ultra-high-molecular-weight polyethylene (UHMWPE) particulate wear debris, highly cross-linked polyethylene (HXPE) bearings have been introduced in total hip arthroplasty (THA). In vitro hip simulator wear studies with HXPE have demonstrated a decrease in volumetric wear at the hip by 42% to 100% when compared with conventional metal-on-polyethylene bearings. Early to intermediate clinical results suggest that the in vivo wear properties of HXPE products are superior to those of conventional UHMWPE. Second-generation HXPE materials that utilize alternate cross-linking and free radical quenching techniques have been developed and propose to further minimize wear and oxidation.

  View details for PubMedID 18284901

• Modified posterior approach total to hip arthroplasty to enhance joint stability Annual Closed Meeting of the International-Hip-Society Kim, Y. S., Kwon, S. Y., Sun, D. H., Han, S. K., Maloney, W. J. SPRINGER. 2008: 294–99

  Abstract

  We modified the posterior approach by preserving the external rotator muscles to enhance joint stability after primary THA. We asked whether this modified posterior approach would have a lower dislocation rate than the conventional posterior approach, with and without a repair of external rotator muscles. We retrospectively divided 557 patients (670 hips) who had undergone primary THA into three groups based on how the external rotator muscles had been treated during surgery: (1) not repaired after sectioning, (2) repaired after sectioning, or (3) not sectioned and preserved. The minimum followup was 1 year. In the group with preserved external rotator muscles, we observed no dislocations; in comparison, the dislocation rates for the repaired rotator group and the no-repair group were 3.9% and 5.3%, respectively. This modified posterior approach, which preserves the short external rotator muscles, seemed effective in preventing early dislocation after primary THA.Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1007/s11999-007-0056-8

  View details for Web of Science ID 000253164100007

  View details for PubMedID 18196409

• What is the outcome of treatment for osteolysis? AAOS/NIH Osteolysis and Implant Wear: Biological, Biomedical Engineering, and Surgical Principles Maloney, W., Rosenberg, A. AMER ACAD ORTHOPAEDIC SURGEONS. 2008: S26–S32

  Abstract

  Periprosthetic osteolysis secondary to wear-induced particle generation is a common long-term complication of hip and knee replacement and frequently results in the need for revision surgery. Management of significant bone defects remains a surgical challenge. Surgical intervention must address the wear particle generator (usually, but not always, the bearing surface), the osteolytic defects, and implant-related issues, primarily fixation and alignment. Indications for surgical intervention in the absence of loosening and pain are not well established. In general, patient age and activity level, the location and size of the osteolytic defect, and the clinical record of the implant system will dictate treatment choices.

  View details for PubMedID 18612010

• Torsional strength estimates of femoral diaphyses with endosteal lytic lesions: Dual-energy x-ray Absorptiometry study JOURNAL OF ORTHOPAEDIC RESEARCH Robertson, D. D., Beck, T. J., Chan, B. W., Scott, W. W., Sharma, G. B., Maloney, W. J. 2007; 25 (10): 1343-1350

  Abstract

  Pathologic fracture is a significant problem for individuals with metastatic bone disease. Current guidelines for prophylactic internal fixation are neither reliable nor easily applied. The purpose of this study was to validate dual-energy X-ray absorptiometry (DXA) as an accurate method for estimating torsional bone strength of diaphyseal bone with endosteal lytic lesions. Endosteal lesions of varying sizes were simulated in the diaphyses of 12 adult cadaveric femurs. Unaltered contralateral femurs served as matched controls. Machined lesions ranged from 3 to 6.5 cm in length, 1 to 3 cm in width, 15 to 48 cm(2) in elliptical area, with 10% to 100% removal of the cortical thickness. Morphology and density data obtained from DXA images were used to estimate torsional strength. All femora were mechanically tested to failure in torsion. Physically measured torsional strength was not significantly correlated to lesion elliptical area (r = 0.542, p > 0.05) or percentage cortical thickness removed (r = 0.257, p > 0.05). Measured torsional strength was significantly correlated to DXA-based torsional strength estimates (r = 0.855, p < 0.01). Lesion size alone did not correlate with the strength of bones with simulated endosteal lytic lesions. In contrast, calculations based on DXA (morphology, density) did correlate with torsional strength. This is the first step in the development of a DXA-based tool for objectively estimating bone strength in the presence of endosteal lytic lesions.

  View details for DOI 10.1002/jor.20419

  View details for Web of Science ID 000249671000010

  View details for PubMedID 17549708

• The 2007 ABJS Marshall Urist Award - The impact of direct-to-consumer advertising in orthopaedics CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Bozic, K. J., Smith, A. R., Hariri, S., Adeoye, S., Gourville, J., Maloney, W. J., Parsley, B., Rubash, H. E. 2007: 202-219

  Abstract

  Direct-to-consumer advertising (DTCA) has become an influential factor in healthcare delivery in the United States. We evaluated the influence of DTCA on surgeon and patient opinions and behavior in orthopaedics by surveying orthopaedic surgeons who perform hip and knee arthroplasties and patients who were scheduled to have hip or knee arthro-plasty. Respondents were asked for their opinions of and experiences with DTCA, including the influence of DTCA on surgeon and patient decision making. Greater than 98% of surgeon respondents had experience with patients who were exposed to DTCA. The majority of surgeon respondents reported DTCA had an overall negative impact on their practice and their interaction with patients (74%), and their patients often were confused or misinformed about the appropriate treatment for their condition based on an advertisement (77%). Fifty-two percent of patient respondents recalled seeing or hearing advertisements related to hip or knee arthroplasty. These patients were more likely to request a specific type of surgery or brand of implant from their surgeon and to see more than one surgeon before deciding to have surgery. Direct-to-consumer advertising seems to play a substantial role in surgeon and patient decision making in orthopaedics. Future efforts should be aimed at improving the quality and accuracy of information contained in consumer-directed advertisements related to orthopaedic implants and procedures.

  View details for DOI 10.1097/BLO.0b013e31804fdd02

  View details for Web of Science ID 000246259200038

  View details for PubMedID 17353799

• Clinical presentation of patients with tears of the acetabular labrum. journal of bone and joint surgery. American volume Burnett, R. S., Della Rocca, G. J., Prather, H., Curry, M., Maloney, W. J., Clohisy, J. C. 2006; 88 (7): 1448-1457

  Abstract

  The clinical presentation of a labral tear of the acetabulum may be variable, and the diagnosis is often delayed. We sought to define the clinical characteristics associated with symptomatic acetabular labral tears by reviewing a group of patients who had an arthroscopically confirmed diagnosis.We retrospectively reviewed the records for sixty-six consecutive patients (sixty-six hips) who had a documented labral tear that had been confirmed with hip arthroscopy. We had prospectively recorded demographic factors, symptoms, physical examination findings, previous treatments, functional limitations, the manner of onset, the duration of symptoms until the diagnosis of the labral tear, other diagnoses offered by health-care providers, and other surgical procedures that these patients had undergone. Radiographic abnormalities and magnetic resonance arthrography findings were also recorded.The study group included forty-seven female patients (71%) and nineteen male patients (29%) with a mean age of thirty-eight years. The initial presentation was insidious in forty patients, was associated with a low-energy acute injury in twenty, and was associated with major trauma in six. Moderate to severe pain was reported by fifty-seven patients (86%), with groin pain predominating (sixty-one patients; 92%). Sixty patients (91%) had activity-related pain (p < 0.0001), and forty-seven patients (71%) had night pain (p = 0.0006). On examination, twenty-six patients (39%) had a limp, twenty-five (38%) had a positive Trendelenburg sign, and sixty-three (95%) had a positive impingement sign. The mean time from the onset of symptoms to the diagnosis of a labral tear was twenty-one months. A mean of 3.3 health-care providers had been seen by the patients prior to the definitive diagnosis. Surgery on another anatomic site had been recommended for eleven patients (17%), and four had undergone an unsuccessful operative procedure prior to the diagnosis of the labral tear. At an average of 16.4 months after hip arthroscopy, fifty-nine patients (89%) reported clinical improvement in comparison with the preoperative status.The clinical presentation of a patient who has a labral tear may vary, and the correct diagnosis may not be considered initially. In young, active patients with a predominant complaint of groin pain with or without a history of trauma, the diagnosis of a labral tear should be suspected and investigated as radiographs and the history may be nonspecific for this diagnosis.Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

  View details for PubMedID 16818969

• Clinical presentation of patients with tears of the acetabular labrum JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Burnett, R. S., Della Rocca, G. J., Prather, H., Curry, M., Maloney, W. J., Clohisy, J. C. 2006; 88A (7): 1448-1457

  View details for DOI 10.2106/JBJS.E.02806

  View details for Web of Science ID 000238701800004

• Efficacy of combined modality prophylaxis including short-duration warfarin to prevent venous thromboembolism after total hip arthroplasty JOURNAL OF ARTHROPLASTY Keeney, J. A., Clohisy, J. C., Curry, M. C., Maloney, W. J. 2006; 21 (4): 469-475

  Abstract

  This study reviewed the effectiveness of a trimodality deep venous thrombosis (DVT) prophylactic regimen after primary and revision total hip arthroplasty. Seven hundred five patients were treated with pneumatic compression, adjusted dose warfarin (7 days), and early mobilization. Bilateral lower extremity venous ultrasonography was obtained on postoperative day 3 or 4. The incidence of asymptomatic DVT, symptomatic DVT/pulmonary embolus events within 90 days of surgery, and potential influence of risk factors was retrospectively assessed. Deep venous thrombosis incidence was 4.4% with one (0.1%) nonfatal pulmonary embolus. Increased age, male sex, and DVT history were significant risk factors for thromboembolic events within 90 days of hip arthroplasty. The combination of short-duration warfarin and mechanical prophylaxis with predischarge ultrasound screening was safe and effective in limiting the occurrence of venous thromboembolism.

  View details for DOI 10.1016/j.arth.2005.06.017

  View details for Web of Science ID 000238705200001

  View details for PubMedID 16781396

• Management of acetabular bone loss. Instructional course lectures Maloney, W. J., Wadey, V. M. 2006; 55: 279-285

  Abstract

  Acetabular bone loss is a common complication associated with revision total joint replacement. Successful surgical management is enhanced by a systematic classification of bony defects. A variety of implants, fixation strategies, surgical techniques, and graft materials are required to address the spectrum of reconstructive complications encountered at revision surgery.

  View details for PubMedID 16958463

• Removal of well-fixed cementless components. Instructional course lectures Maloney, W. J., Wadey, V. M. 2006; 55: 257-261

  Abstract

  Removal of stable, osseointegrated cementless components can be a challenge for the orthopaedic surgeon. Careful preoperative planning to assess the location and extent of the bone ingrowth or ongrowth as well as ensuring that the appropriate instrumentation is available in the operating room can help minimize complications when performing these procedures.

  View details for PubMedID 16958461

• Acetabular and femoral radiographic abnormalities associated with labral tears CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Peelle, M. W., Della Rocca, G. J., Maloney, W. J., Curry, M. C., Clohisy, J. C. 2005: 327-333

  Abstract

  The purpose of our study was to define the incidence of acetabular and femoral osseous abnormalities associated with symptomatic acetabular labral tears. We reviewed the radiographs of 78 patients treated arthroscopically for labral tears and 22 patients with asymptomatic hips for comparison. Overall, 49% of patients with labral tears had at least one radiographic abnormality (17% acetabular, 14% femoral, and 18% both). Hip dysplasia was more prevalent in patients with labral tears (36%) compared with control subjects (0%). A decreased head-neck offset was present in 18% of patients with labral tears versus 5% of the control subjects. An anterolateral prominence at the femoral head-neck junction, creating an aspherical femoral head, was present in 29% of patients with labral tears. Sixty-one percent of those patients also met criteria for dysplasia and/or decreased head-neck offset. A retroverted acetabulum was present in 12% of patients with labral tears and none of the control subjects. Osteoarthritis was more common in patients with labral tears (33%) than in control subjects (9%). Because acetabular and femoral osseous abnormalities commonly are associated with labral tears, recognition of these abnormalities is important to optimize surgical treatment of patients with symptomatic labral disease. Level of Evidence: Diagnostic study, Level II (development of diagnostic criteria on consecutive patients-with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1097/01.blo.0000181147.86058.74

  View details for Web of Science ID 000233794700049

  View details for PubMedID 16331022

• Revision total knee arthroplasty for restricted motion Meeting of the Knee-Society Keeney, J. A., Clohisy, J. C., Curry, M., Maloney, W. J. SPRINGER. 2005: 135–40

  Abstract

  Persistent stiffness is an infrequent but notable complication occurring after total knee arthroplasty. A limited approach (soft tissue releases and component retention with tibial insert downsizing) has previously been associated with poor results, although comprehensive revision of both components seems more successful. We retrospectively reviewed 23 patients (25 knees) who had revision total knee arthroplasty for painful limitation of motion. At a mean of 36.7 months after surgery we assessed pain, motion arc, and Knee Society clinical and functional scores. The effectiveness of a limited approach for selected patients (n = 12) was compared with more comprehensive revision of both components (n = 11). Patients with the limited approach had improvements in mean knee motion arc (25.7 degrees), mean clinical score (37.8 points), and mean functional score (20.8 points). Patients with component revision had a mean improvement in knee motion arc (17.9 degrees) but little change in the clinical score (3.6 points) or functional score (-1.0 points). The severity of preoperative flexion contractures and limited motion in patients having component revision likely contributed to the limited improvement. The data suggest a limited soft tissue approach may be appropriate for a select group of patients. The success of component revision for patients with severely restricted motion and more extensive flexion contracture was less predictable than authors of previous reports suggest.Therapeutic study, Level III-1 (retrospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

  View details for DOI 10.1079/01.blo.0000185312.43955.c8

  View details for Web of Science ID 000233231000025

  View details for PubMedID 16239797

• The surgical management of femoral osteolysis 4th Annual Spring Meeting on Current Concept in Joint Replacement Maloney, W. J. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2005: 75–78

  Abstract

  Fifteen patients underwent reoperation for failed total hip arthroplasty. At surgery, patients who had proximal femoral osteolysis with osseointegrated femoral components were managed with lesional treatment that included debridement and bone grafting. The femoral components included 7 extensively coated stems, 5 proximally coated stems, and 3 modular femoral components. At a minimum 5-year follow-up evaluation, all 15 femoral components remained radiographically stable. Graft material in contained defects appeared to consolidate radiographically. For selected patients, debridement and grafting of femoral osteolytic defects provide satisfactory intermediate term outcomes.

  View details for DOI 10.1016/j.arth.2005.03.019

  View details for Web of Science ID 000230134300022

  View details for PubMedID 15991137

• Prospective dosing of warfarin based on cytochrome P-4502C9 genotype THROMBOSIS AND HAEMOSTASIS Voora, D., Eby, C., Linder, M. W., Milligan, P. E., Bukaveckas, B. L., McLeod, H. L., Maloney, W., Clohisy, J., Burnett, R. S., Grosso, L., Gatchel, S. K., Gage, B. F. 2005; 93 (4): 700-705

  Abstract

  Cytochrome P-450 2C9 (CYP2C9) polymorphisms (CYP2C9*2 and CYP2C9*3) reduce the clearance of warfarin, increase the risk of bleeding, and prolong the time to stable dosing. Whether prospective use of a retrospectively developed algorithm that incorporates CYP2C9 genotype and nongenetic factors can ameliorate the propensity to bleeding and delay in achieving a stable warfarin dose is unknown. We initiated warfarin therapy in 48 orthopedic patients tailored to the following variables: CYP2C9 genotype, age, weight, height, gender, race, and use of simvastatin or amiodarone. By using pharmacogenetics-based dosing, patients with a CYP2C9 variant achieved a stable, therapeutic warfarin dose without excessive delay. However compared to those without a CYP2C9 variant, patients with a variant continued to be at increased risk (hazard ratio 3.6, 95% confidence interval 1.4-9.5, p = 0.01) for an adverse outcome (principally INR > 4), despite pharmacogenetics-based dosing. There was a linear relationship (R(2) = 0.42, p < 0.001) between the pharmacogenetics-predicted warfarin doses and the warfarin maintenance doses, prospectively validating the dosing algorithm. Prospective, perioperative pharmacogenetics-based dosing of warfarin is feasible; however, further evaluation in a randomized, controlled study is recommended.

  View details for DOI 10.1160/TH04-08-0542

  View details for Web of Science ID 000228393000012

  View details for PubMedID 15841315

• In vivo transplantation of neonatal ovine neocartilage allografts: determining the effectiveness of tissue transglutaminase. The journal of knee surgery Lu, Y., Adkisson, H. D., Bogdanske, J., Kalscheur, V., Maloney, W., Cheung, R., Grodzinsky, A. J., Hruska, K. A., Markel, M. D. 2005; 18 (1): 31-42

  Abstract

  Following transplantation of ovine neocartilage allografts, 26 sheep were divided into groups according to the following weight-bearing schedule: 8-week nonweight bearing (8NWB, n=14), and 8-week nonweight bearing+4-week weight bearing (8NWB+4WB, n=12). In addition, 7 and 6 sheep, respectively, in the 8NWB and 8NWB+4WB groups received tTG treatment after allograft transplantation, whereas the remaining 13 sheep in these groups did not receive tTG. Finally, 8 sheep served as sham-operated controls without allograft transplantation. After euthanasia, stifle joints were harvested for the analysis of gross appearance, chondrocyte viability, histology, and biomechanical testing. No significant differences were noted in macroscopic graft survival and union with host tissue in both 8NWB and 8NWB+4WB groups between the tTG treated and non-tTG treated animals. Analysis of histological scores demonstrated no significant difference between tTG and non-tTG treatments in both 8NWB and 8NWB+4WB groups. Confocal laser microscopic analysis of the explanted defects revealed 70%-100% cell viability in all treatment groups. This study shows that allogeneic chondrocytes harvested from neonatal donors provide sufficient metabolic activity to affect repair. Use of tTG to augment resorbable suture fixation of neocartilage grafts provided no advantage over suture alone in this pilot study.

  View details for PubMedID 15742595

• Magnetic resonance arthrography versus arthroscopy in the evaluation of articular hip pathology Hip-Society 2004 Meeting Keeney, J. A., Peelle, M. W., Jackson, J., Rubin, D., Maloney, W. J., Clohisy, J. C. SPRINGER. 2004: 163–69

  Abstract

  In this study, we compared magnetic resonance arthrography results with hip arthroscopy findings to assess the diagnostic value of this imaging technique in evaluating acetabular labral tears and concurrent articular hip pathology. One hundred one consecutive patients (102 hips) with a clinical diagnosis of acetabular labral tear were assessed using magnetic resonance arthrography and had hip arthroscopy after failing to improve with nonoperative treatment. Magnetic resonance arthrography detected 71 of 93 (76%) acetabular labral tears (92 patients) with five false positive studies in five patients (4.9%). Articular cartilage findings diagnosed by magnetic resonance arthrography were confirmed by arthroscopy in 64 hips in 64 patients (62.7%). With respect to labral pathology, magnetic resonance arthrography showed a sensitivity of 71%, specificity of 44% positive predictive value of 93%, negative predictive value of 13%, and accuracy of 69%. With respect to articular cartilage pathology, magnetic resonance arthrography had a sensitivity of 47%, specificity of 89%, positive predictive value of 84%, negative predictive value of 59%, and accuracy of 67%. Although magnetic resonance arthrography is an excellent positive predictor in diagnosing acetabular labral tears and articular cartilage abnormalities, it has limited sensitivity. A negative imaging study does not exclude important intra-articular pathology that can be identified and treated arthroscopically.

  View details for DOI 10.1097/01.blo.0000150125.34906.7d

  View details for Web of Science ID 000225549900025

  View details for PubMedID 15577482

• Biomechanics of large femoral heads - What they do and don't do Hip-Society 2004 Meeting Crowninshield, R. D., Maloney, W. J., Wentz, D. H., Humphrey, S. M., Blanchard, C. R. SPRINGER. 2004: 102–7

  Abstract

  The stability and durability of total hip reconstruction is dependent on many factors that include the design and anatomic orientation of prosthetic components. An analysis of femoral component head size and acetabular component orientation shows an interdependency of these variables and joint stability. Increased femoral component head size can increase hip stability by increasing the prosthetic impingement-free range of hip motion and by increasing the inferior head displacement required before hip dislocation. Increasing the femoral head size from 22 mm to 40 mm increases the required displacement for dislocation by about 5 mm with the acetabular component at 45 degrees of abduction; however, increasing acetabular component abduction greatly diminishes this stability advantage of larger femoral heads. Vertical acetabular component orientation and femoral component head subluxation are each predicted to more than double the tensile stress with acetabular component polyethylene compared with components at 45 degrees of abduction. With a desirable acetabular component orientation, the use of larger femoral heads may result in improved joint stability and durable use of polyethylene. With high abduction acetabular component orientation, the use of larger femoral heads contributes little to joint stability and contributes to elevated stress within the polyethylene that may result in implant failure.

  View details for DOI 10.1097/01.blo.0000150117.42360.f9

  View details for Web of Science ID 000225549900016

  View details for PubMedID 15577473

• Reasons for revision hip surgery - A retrospective review Hip-Society 2004 Meeting Clohisy, J. C., Calvert, G., Tull, F., McDonald, D., Maloney, W. J. SPRINGER. 2004: 188–92

  Abstract

  The purpose of this study was to determine the indications for contemporary revision hip surgery in a consecutive series of patients. We retrospectively reviewed the clinical records and radiographs of 439 revision hip surgeries done between 1996 and 2003. Fifty-five percent of the surgeries were for aseptic loosening, 14% were for instability, 13% were for osteolysis around a well-fixed implant, 7% were for infection, 5% were for periprosthetic fracture, 3% were for conversion of a hemiarthroplasty, 1% was for psoas impingement, 1% was for loose recalled implants, and 1% was for implant fracture. As expected, aseptic loosening was the most common reason for revision surgery. Instability was a common reason for early revision whereas revision for osteolysis around a well-fixed implant was a more common reason for late revision.

  View details for DOI 10.1097/01.blo.0000150126.73024.42

  View details for Web of Science ID 000225549900029

  View details for PubMedID 15577486

• Leg length discrepancy after total hip arthroplasty Meeting on Current Concepts in Joint Replacement Maloney, W. J., Keeney, J. A. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2004: 108–10

  Abstract

  Restoration of hip biomechanics, including femoral offset and leg length are desired goals in performing total hip arthroplasty. Minor leg length discrepancies, less than a centimeter, are common after total hip arthroplasty and usually well tolerated. However in some patients, even these small discrepancies are a source of dissatisfaction. In addition, more significant discrepancies can be a risk factor for nerve injury and are a relatively common cause of litigation. Although leg length discrepancy cannot be eliminated after hip arthroplasty, it can be minimized through a series of steps both preoperatively and intraoperatively. These include physical examination to determine true and apparent leg length, and radiographic evaluation to both assess leg length and to preoperatively template the surgical procedure. Finally, the preoperative plan needs to be executed in the operating room using appropriate intraoperative cues.

  View details for DOI 10.1016/j.arth.2004.02.018

  View details for Web of Science ID 000222353400025

  View details for PubMedID 15190563

• An AOA critical issue the outcome of the outcomes movement Joint Annual Meeting of the American-Orthopaedic-Association/Canadian-Orthopaedic-Association Bourne, R. B., Maloney, W. J., Wright, J. G. JOURNAL BONE JOINT SURGERY INC. 2004: 633–40

  View details for Web of Science ID 000189272900026

• An AOA critical issue. The outcome of the outcomes movement. journal of bone and joint surgery. American volume Bourne, R. B., Maloney, W. J., Wright, J. G. 2004; 86-A (3): 633-640

  View details for PubMedID 14996894

• The role of proximal femoral support in stress development within hip prostheses CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Crowninshield, R. D., Maloney, W. J., Wentz, D. H., Levine, D. L. 2004: 176-180

  Abstract

  Bone remodeling commonly associated with implant loosening may require revision total hip replacement when there is substantial proximal femoral bone loss. Additionally, the surgical exposure required to remove primary implants may alter the proximal femur's structure. As a result, in many revision hip situations the proximal femur provides compromised support for the revision femoral component. Stress analyses of the proximal femur with extensively porous-coated prosthetic femoral components show that proximomedial femoral bone loss, ununited femoral osteotomy, and periprosthetic fracture can result in significant elevation of stress within revision prosthetic components. The first principal stress within prosthetic components can, in proximal bone loss conditions, be elevated significantly above a revision prostheses' fatigue strength. Loss of proximomedial bone is predicted to increase stress within a revision component by as much as 82%. An unhealed transverse femoral fracture or osteotomy is predicted to more than double the stress within a revision femoral component. In revision total hip replacement, efforts directed toward the restoration of proximal femoral bone and the use of larger prostheses may contribute to avoiding prostheses fatigue fracture. Similarly, protected weightbearing in patients with ununited femoral osteotomies and periprosthetic fractures may be important to preventing prosthetic fracture.

  View details for Web of Science ID 000220580200024

  View details for PubMedID 15057094

• Adenovirus mediated BMP-13 gene transfer induces chondrogenic differentiation of murine mesenchymal progenitor cells JOURNAL OF BONE AND MINERAL RESEARCH Nochi, H., Sung, J. H., Lou, J., Adkisson, H. D., Maloney, W. J., Hruska, K. A. 2004; 19 (1): 111-122

  Abstract

  Chondrogenic/osteogenic differentiation of a mesenchymal progenitor stimulated by BMP-13 (CDMP-2) was studied. C3H10T1/2 cells were transduced by an adenoviral construct containing BMP-13 or BMP-2. BMP-13 supported chondrogenesis but not terminal differentiation, whereas BMP-2 stimulated endochondral ossification. The studies show that BMP-13 may fail to support terminal chondrocyte differentiation.Bone morphogenetic protein (BMP)-13 is a member of the transforming growth factor beta (TGF-beta) superfamily of growth factors. Although the biological functions of BMP-13 remain poorly understood, continued postnatal expression of BMP-13 in articular cartilage suggests that this protein may function in an autocrine/paracrine fashion to regulate growth and maintenance of articular cartilage. The purpose of this study was to elucidate the role of BMP-13 in chondrogenic differentiation.Replication-deficient adenoviruses carrying human BMP-13 (Adv-hBMP13), bacterial beta-galactosidase (Adv-beta gal), and human BMP-2 (Adv-hBMP2) were constructed. Murine mesenchymal progenitor cells (C3H10T1/2) were transduced with these vectors, and differentiation to the chondrogenic lineage was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR), biochemical, and histological analyses.Our findings revealed that hBMP-13 transduced cells differentiated into round cells that stained with Alcian blue. Analysis of gene expression in hBMP-13-transduced cells demonstrated presence of cartilage-specific markers, absence of hypertrophic chondrocyte specific markers, and upregulation of proteoglycan biosynthesis. In particular, hBMP-13-transduced cells had significantly less and delayed expression of alkaline phosphatase activity and calcium mineral accumulation than hBMP-2-transduced cells. Except for BMPR-IB/ALK-6, expression of BMP receptors was identified constitutively in C3H10T1/2 cells and was not affected by the presence of either of the BMPs. In summary, hBMP-13, while stimulating chondrogenesis, failed to support differentiation to hypertrophic chondrocytes and endochondral ossification similar to hBMP-2. Thus, this may prove to be a useful strategy for cell-based regeneration of articular cartilage.

  View details for Web of Science ID 000187567800014

  View details for PubMedID 14753743

• Fluoroscopic analyses of cruciate-retaining and medial pivot knee implants CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Schmidt, R., Komistek, R. D., Blaha, J. D., Penenberg, B. L., Maloney, W. J. 2003: 139-147

  Abstract

  Contemporary posterior cruciate-retaining total knee designs have provided pain relief and improved knee function but have failed to reproduce the kinematics and stability of the normal nonarthritic knee. The Medial Pivot total knee design features a near constant radius of curvature of the femoral component. The tibial surface is highly congruent and asymmetric, permitting a medial pivot motion during knee flexion. The purpose of the current study was to analyze and compare the gait kinematics of the Sigma posterior cruciate-retaining total knee implant, the Advance Traditional posterior cruciate-retaining total knee implant, and the Advance Medial Pivot knee implant using fluoroscopic analysis. In vivo kinematics were determined for 15 clinically successful total knee arthroplasties. Five knee implants were evaluated from each group. The authors analyzed the kinematics of knee motion during the stance phase of gait for each patient. On average, subjects with the Medial Pivot knee implant had a medial pivot motion. Both posterior cruciateretaining designs had a paradoxical roll forward of the tibia on femur during knee flexion and had greater excursion of both condyles during knee flexion than the medial pivot design. Nine of 10 of the posterior cruciate-retaining designs had condylar lift-off averaging 1.7 mm whereas only one Medial Pivot knee implant had condylar lift-off measuring 1.1 mm.

  View details for DOI 10.1097/01.blo.0000063565.90853.a4

  View details for Web of Science ID 000182630400015

  View details for PubMedID 12771824

• Cementless and cemented implants had similar survival in total knee replacement. journal of bone and joint surgery. American volume Maloney, W. J. 2003; 85-A (5): 973-?

  View details for PubMedID 12728060

• Femoral component design and patellar clunk syndrome CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Schmidt, R., Sculco, T. P. 2003: 199-202

  Abstract

  The effect of patellar design of the femoral component on the prevalence of patellar clunk was examined by comparing 179 consecutive Insall-Burstein II posterior-stabilized total knee replacements with 210 consecutive primary Advanced posterior-stabilized total knee replacements. In the Advanced posterior-stabilized knee replacements, the patellofemoral groove had been extended posteriorly 7.5 mm compared with the Insall-Burstein II implant. At a minimum followup of 2 years, the prevalence of patellar clunk syndrome in the patients with a Insall-Burstein II knee replacement was 3.9% (seven of 179) compared with 0% in the patients with an Advanced posterior-stabilized knee replacement. Based on these data, it seems that the design change in patellofemoral groove of the Advanced posterior-stabilized knee replacement has eliminated the problem of patellar clunks.

  View details for DOI 10.1097/01.blo.0000063606.67412.96

  View details for Web of Science ID 000182630400022

  View details for PubMedID 12771831

• Knee kinematics and total knee replacement design. Clinical orthopaedics and related research Maloney, W. J., Clohisy, J. C. 2003: 3-4

  View details for PubMedID 12771810

• Human serum opsonization of orthopedic biomaterial particles: Protein-binding and monocyte/macrophage activation in vitro JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A Sun, D. H., Trindade, M. C., Nakashima, Y., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 2003; 65A (2): 290-298

  Abstract

  Wear particles generated after total joint arthroplasty activate monocyte/macrophages and incite formation of a granulomatous periprosthetic tissue associated with bone loss and implant loosening. This study tested the hypothesis that selective opsonization of orthopedic implant biomaterial wear particles by human serum proteins influences monocyte/macrophage activation. Serum protein binding to metallic, polymeric, and ceramic particles was determined by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Individual proteins bound to particles were subsequently identified using two-dimensional SDS-PAGE, microsequencing techniques, and SWISS-PROT analysis. Effects of selective protein opsonization on particle-induced monocyte/macrophage activation were assessed by quantification of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha release. Results from one-dimensional gel analyses revealed distinct serum protein-binding patterns specific for each material tested. Two-dimensional gel analysis together with amino acid sequencing of the prominent protein species confirmed the presence of albumin and alpha-1-antitrypsin bound to all particles tested. In contrast to the metallic particles, apolipoprotein was a major species associated with polymeric particles. Opsonization of PMMA particles with purified preparations of each of the identified proteins showed that albumin significantly enhanced particle-induced monocyte/macrophage activation. These data confirm orthopedic biomaterial specific binding of human serum proteins and demonstrate that albumin exacerbates particle-induced monocyte/macrophage activation. Alterations in the chemical and surface properties of orthopedic biomaterials to modulate protein interactions may improve implant longevity.

  View details for DOI 10.1002/jbm.a.10477

  View details for Web of Science ID 000182627600022

• Human serum opsonization of orthopedic biomaterial particles: protein-binding and monocyte/macrophage activation in vitro. Journal of biomedical materials research. Part A Sun, D., Trindade, M. C., Nakashima, Y., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 2003; 65 (2): 290-298

  Abstract

  Wear particles generated after total joint arthroplasty activate monocyte/macrophages and incite formation of a granulomatous periprosthetic tissue associated with bone loss and implant loosening. This study tested the hypothesis that selective opsonization of orthopedic implant biomaterial wear particles by human serum proteins influences monocyte/macrophage activation. Serum protein binding to metallic, polymeric, and ceramic particles was determined by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Individual proteins bound to particles were subsequently identified using two-dimensional SDS-PAGE, microsequencing techniques, and SWISS-PROT analysis. Effects of selective protein opsonization on particle-induced monocyte/macrophage activation were assessed by quantification of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha release. Results from one-dimensional gel analyses revealed distinct serum protein-binding patterns specific for each material tested. Two-dimensional gel analysis together with amino acid sequencing of the prominent protein species confirmed the presence of albumin and alpha-1-antitrypsin bound to all particles tested. In contrast to the metallic particles, apolipoprotein was a major species associated with polymeric particles. Opsonization of PMMA particles with purified preparations of each of the identified proteins showed that albumin significantly enhanced particle-induced monocyte/macrophage activation. These data confirm orthopedic biomaterial specific binding of human serum proteins and demonstrate that albumin exacerbates particle-induced monocyte/macrophage activation. Alterations in the chemical and surface properties of orthopedic biomaterials to modulate protein interactions may improve implant longevity.

  View details for PubMedID 12734824

• Orthopaedic crossfire--Larger femoral heads: a triumph of hope over reason! In opposition. journal of arthroplasty Maloney, W. J. 2003; 18 (3): 85-87

  Abstract

  For the past decade, large femoral heads have for the most part been avoided in total hip arthroplasty, especially in younger active patients, because of their association with increased polyethylene wear. However, it has become equally clear that large femoral heads offer a benefit in terms of hip stability and reducing postoperative dislocation. With increasing head size, there is less chance of component-on-component impingement and increased displacement for dislocation. Highly cross-linked polyethylene appears to be relatively insensitive to head size and may offer the surgeon the opportunity to use large femoral heads, especially in patients who are at high risk for dislocation.

  View details for PubMedID 12730936

• Hip biomechanics: importance to functional imaging. Seminars in musculoskeletal radiology Robertson, D. D., Britton, C. A., Latona, C. R., Armfield, D. R., Walker, P. S., Maloney, W. J. 2003; 7 (1): 27-41

  Abstract

  Although well recognized the hip joint is not well understood. In many respects knowledge of the hip is similar to that of the knee several decades ago. Increased understanding of the hip's structure and function will improve our ability to diagnose and treat pre-end-stage hip joint disease. This article describes relevant anatomy and mechanics and details the crucial role that imaging plays in current assessments of hip function.

  View details for PubMedID 12888942

• Stimulation of BMP-2 expression by pro-inflammatory cytokines IL-1 and TNF-alpha in normal and osteoarthritic chondrocytes. journal of bone and joint surgery. American volume Fukui, N., Zhu, Y., Maloney, W. J., Clohisy, J., Sandell, L. J. 2003; 85-A: 59-66

  Abstract

  Destruction of cartilage in osteoarthritis is a direct effect of an imbalance between catabolic and anabolic activities in the tissue. While a great deal is known about catabolism, we sought to determine the biochemical basis of the anabolic activity.Cartilage was isolated from normal and osteoarthritic patients and subjected to both cell and explant culture. mRNA expression levels of the growth and differentiation factors bone morphogenetic protein-2 (BMP-2), BMP-4, BMP-6, cartilage-derived morphogenetic protein-1 (CDMP-1), connective tissue growth factor (CTGF), and activin were determined. BMP-2 was localized in osteoarthritic cartilage by immunohistochemistry. To determine the mechanism of BMP-2 stimulation, chondrocytes were cultured with TGF-beta (transforming growth factor-beta), insulin-like growth factor-1 (IGF-1), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha). The BMP-2 response was monitored by quantitative real-time polymerase chain reaction to ascertain mRNA levels and by Western blot analysis, BMP-2 protein quantitation, and immunohistochemistry to determine protein levels.BMP-2 was found to be up-regulated in osteoarthritic chondrocytes and cartilage. In cell culture, IL-1beta and TNF-alpha increased BMP-2 mRNA and protein levels by eightfold and fifteenfold, respectively, whereas IGF-1 and TGF-beta1 had no effect. In cartilage explant cultures, IL-1beta and TNF-alpha increased BMP-2 levels both intracellularly and extracellularly. Functional relevance was suggested by co-localization of BMP-2 and newly synthesized type-II procollagen within the same cells.BMP-2 acts as a stimulus of anabolic activities in normal and osteoarthritic chondrocytes. Furthermore, the pro-inflammatory cytokines IL-1beta and TNF-alpha, known to be present in synovium and cartilage of patients with osteoarthritis, stimulate the production of active BMP-2.

  View details for PubMedID 12925611

• Stimulation of BMP-2 expression by pro-inflammatory cytokines IL-1 and TNF-alpha in normal and osteoarthritic chondrocytes 4th International Conference on Bone Morphogenetic Proteins Fukui, N., Zhu, Y., Maloney, W. J., Clohisy, J., Sandell, L. J. JOURNAL BONE JOINT SURGERY INC. 2003: 59–66

  View details for Web of Science ID 000184680500011

• Analysis of long-term cemented total hip arthroplasty retrievals 8th Meeting of the Hip-Society Maloney, W. J., Schmalzried, T., Harris, W. H. SPRINGER. 2002: 70–78

  Abstract

  A detailed biomechanical, histologic, and histomorphometric analysis of autopsy specimens from patients who previously had cemented total hip arthroplasty has helped to elucidate the skeletal response to cemented components. Bone cement has the capacity to provide long-term implant stability. The biologic response to polyethylene wear debris has a more critical effect on destabilization of cemented sockets compared with the femoral side. In contrast, mechanical events tended to predominate the early mode of destabilization of cemented femoral components with debonding at the metal-cement interface and fracture in the cement. Fractures predominate in cement mantles less than 1 mm thick and are associated with mantle defects, debonded interfaces, and sharp corners of the implants. Correlation of the histologic findings at the cement-bone interface with radiolucencies seen on clinical radiographs show that on the acetabular side radiolucencies represent a soft tissue membrane that is the biologic response to polyethylene debris. In contrast, on the femoral side, most radiolucencies were as a result of skeletal remodeling. Femoral adaptive bone remodeling is a diffuse process that occurs over the entire fixation surface. The most profound disuse osteoporosis occurred proximally in the proximal medial quadrant; however, when one takes into account all four quadrants, anterior, posterior, medial, and lateral, the most severe osteoporosis occurred at the midpoint of the stem.

  View details for DOI 10.1097/01.blo.0000038060.29678.90

  View details for Web of Science ID 000179861400009

  View details for PubMedID 12461358

• Enhanced cross-linked polymers: The promise - In the affirmative ORTHOPEDICS Maloney, W. J. 2002; 25 (9): 936-937

  View details for Web of Science ID 000178008700013

  View details for PubMedID 12269417

• An American implant registry: A clinical use trip wire ORTHOPEDICS Maloney, W. J. 2002; 25 (9): 923-924

  View details for Web of Science ID 000178008700007

  View details for PubMedID 12269411

• Case challenges in knee surgery - What would you do? JOURNAL OF ARTHROPLASTY Hanssen, A. D., Dorr, L. D., Kurosaka, M., Maloney, W. J., Romagnoli, S., Ranawat, C. S. 2002; 17 (4): 83-89

  Abstract

  In an interactive case presentation session, the faculty discussed management of complex primary and revision knee arthroplasty issues. Principles discussed included: preoperative evaluation of the failed knee arthroplasty, intra-articular versus extra-articular deformity correction, ligamentous balancing, managing the unstable total knee arthroplasty, bone deficiency management, rotational positioning of prosthetic components, selection of articular constraint in the revision knee, and extensor mechanism balancing.

  View details for DOI 10.1054/arth.2002.32546

  View details for Web of Science ID 000176377400024

  View details for PubMedID 12068413

• Common threads in hip, knee, and shoulder arthroplasty Spring 2001 Current Concepts in Joint Replacement Meeting Maloney, W. J. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2002: 2–2

  View details for DOI 10.1054/arth.2002.32544

  View details for Web of Science ID 000176377400002

  View details for PubMedID 12068391

• The stiff total knee arthroplasty - Evaluation and management Spring 2001 Current Concepts in Joint Replacement Meeting Maloney, W. J. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2002: 71–73

  Abstract

  Arthrofibrosis after total knee arthroplasty is a relatively common complication. A variety of modalities have been employed to treat this problem, including physical therapy, injections, and manipulations. We examined a group of consecutive posterior stabilized total knee arthroplasties to determine the prevalence of arthrofibrosis, as defined by flexion <90 degrees, and the effect of manipulation under anesthesia on outcome. Approximately 11% of the patients met the criteria for arthrofibrosis. Manipulation under anesthesia was successful in improving flexion from an average of 67 degrees premanipulation to 111 degrees postmanipulation. The group that required manipulation did as well statistically as the group as a whole, which had a mean flexion of 114 degrees at 1 year.

  View details for DOI 10.1054/arth.2002.32450

  View details for Web of Science ID 000176377400021

  View details for PubMedID 12068410

• Biochemical analyses of human macrophages activated by polyethylene particles retrieved from interface membranes after failed total hip arthroplasty JOURNAL OF ARTHROPLASTY Chiba, J., Maloney, W. J., Inoue, K., Rubash, H. E. 2001; 16 (8): 101-105

  Abstract

  Human monocyte/macrophages (M/M) were exposed to retrieved ultra-high molecular weight polyethylene (UHMWPE) particles isolated after enzymatic digestion of revision total hip arthroplasty interface membrane tissue samples. The cellular response of human M/M to UHMWPE was compared with the response of these cells to latex particles and culture medium alone. We incubated macrophages in good contact with polyethylene particles using an inverted culture system. Chamber slides on which macrophages were attached were filled with polyethylene particle suspension and sealed with plastic sheets. After the slides were inverted, the incubation was completed. Retrieved UHMWPE particulate debris stimulated human M/M to secrete interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha. Human M/M exposed to retrieved UHMWPE particles secreted significantly more IL-1beta, IL-6, and TNF-alpha compared with M/M exposed to latex particles (P<.05).

  View details for Web of Science ID 000172831900018

  View details for PubMedID 11742459

• Surgical treatment of pelvic osteolysis 7th Open Meeting of the Hip-Society/American-Association-of-Hip-and-Knee-Surgeons Maloney, W. J., Paprosky, W., Engh, C. A., Rubash, H. SPRINGER. 2001: 78–84

  Abstract

  Sixty-eight well-fixed acetabular cups with osteolysis in the pelvis and polyethylene wear were identified from a series of 124 reoperations for failed cementless sockets. The well-fixed sockets requiring reoperation were subdivided based on whether the liner was exchanged and lytic lesion grafted (Type I case) or the socket was removed and a complete revision was done (Type II case). In 40 patients (Type I cases), the polyethylene liner was exchanged and the osteolytic lesions were debrided. Allograft bone chips were packed into the lytic defect in 29 patients. In the remaining 11 patients, the lesions were debrided but not grafted. At final followup, all of the acetabular components were radiographically stable. No new osteolytic lesions were identified. Approximately 1/3 of the lesions had resolved completely regardless of whether they were grafted. The remaining 2/3 had decreased in size. In 28 patients (Type II cases), the socket was revised. Both strategies were successful in arresting the process of osteolysis during the course of this study (mean, 3.5 years). However, removal of well-fixed sockets was associated with significantly more bone loss.

  View details for Web of Science ID 000172493400010

  View details for PubMedID 11764374

• National Joint Replacement Registries: has the time come? journal of bone and joint surgery. American volume Maloney, W. J. 2001; 83-A (10): 1582-1585

  View details for PubMedID 11679613

• In vitro generation of scaffold independent neocartilage CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Adkisson, H. D., Gillis, M. P., Davis, E. C., Maloney, W., Hruska, K. A. 2001: S280-S294

  Abstract

  A novel serum-free culture system was developed in an attempt to generate a three-dimensional hyalinelike neocartilage independent of polymer scaffolds. Neocartilage disks as much as 1.5 mm thick were produced, which were characterized by synthesis of the normal articular cartilage collagens and proteoglycans. In contrast to growth in serum-containing media, chondrocytes from juveniles maintained in static culture under defined serum-free conditions deposited an extracellular matrix that accumulated in the form of tissue disks. Electron microscopic evaluation of neocartilage disks revealed collagenous matrices characteristic of articular cartilage from human infants. The neocartilage did not show terminal chondrocyte differentiation as shown by the absence of Type X collagen production and lack of cellular hypertrophy. Although chondrocytes from preadolescent donor cartilage recapitulated embryonic development in the absence of exogenous factors, chondrocytes from articular cartilage from adults failed to produce neocartilage when grown under identical conditions. This is the first demonstration that autocrine morphogens are sufficient to guide production of hyaline cartilage in vitro. In addition to providing a unique model system to compare the healing response of mature and immature articular chondrocytes, this technology may be of clinical importance in the development of new biomaterials for repair of articular cartilage defects.

  View details for Web of Science ID 000171624500026

  View details for PubMedID 11603712

• Knee challenges: What would you do? ORTHOPEDICS Maloney, W. J., Dorr, L. D., Cuckler, J. M., Whiteside, L. A., Cameron, H. U., Buechel, F. F. 2001; 24 (9): 911-913

  View details for Web of Science ID 000171117000034

  View details for PubMedID 11570483

• Hip challenges: What would you do? ORTHOPEDICS Dorr, L. D., Maloney, W. J., Gie, G., Goldberg, V. M., Engh, C. A., Mallory, T. H. 2001; 24 (9): 907-909

  View details for Web of Science ID 000171117000033

  View details for PubMedID 11570482

• Contemporary issues in total hip arthroplasty. American journal of orthopedics (Belle Mead, N.J.) Berry, D. J., Barrack, R. L., McKellop, H. A., Maloney, W. 2001; 30 (8): 626-632

  View details for PubMedID 11520018

• Ceramic bearing surfaces in total hip arthroplasty 30th Annual Meeting of the Japan-Society-for-Replacement-Arthroplasty Nelsen-Freund, E. M., Jacobs, J. J., Maloney, W. J. SPRINGER-VERLAG TOKYO. 2001: 41–48

  View details for Web of Science ID 000169734800005

• G-protein activity requirement for polymethylmethacrylate and titanium particle-induced fibroblast interleukin-6 and monocyte chemoattractant protein-1 release in vitro JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Trindade, M. C., Schurman, D. J., Maloney, W. J., Goodman, S. B., Smith, R. L. 2000; 51 (3): 360-368

  Abstract

  Periprosthetic granulomatous membranes consisting of fibroblasts, macrophages, lymphocytes, foreign body giant cells, and abundant particulate debris occur at sites of implant loosening. Previous studies demonstrate that fibroblasts respond to particulate debris through the release of interleukin-6 (IL-6), prostaglandin E(2), and matrix metalloproteinases in vitro. C-C chemokines are observed in granulomatous tissue surrounding loosened prosthetic implants and are released by macrophages and fibroblasts in response to particle challenge in vitro. This study tested the hypothesis that G protein activity is required for fibroblast activation by titanium and polymethylmethacrylate (PMMA) particles, and that inhibition of G protein activity would alter IL-6 and and monocyte chemoattractant protein-1 (MCP-1) release from activated fibroblasts. The specific inhibitor of G protein activity, pertussis toxin, was added to the fibroblasts to examine the effects of G protein activity with respect to the production of IL-6 and MCP-1 by orthopedic biomaterial-challenged fibroblasts in vitro. Interleukin-1beta (IL-1beta), a proven activator of MCP-1 and interleukin-6, was used as a positive control. Exposure of fibroblasts to titanium and polymethylmethacrylate (PMMA) particles resulted in a dose-dependent release of MCP-1 and IL-6. Challenge with PMMA particles at doses of 0.150%, 0.300%, and 0.600% vol/vol increased the release of interleukin-6 by 7-, 19-, and 22-fold, respectively, compared to fibroblasts exposed to serum-free culture medium alone at 24 h. Challenge with PMMA particles at doses of 0.075%, 0.150%, 0.300%, and 0.600% vol/vol increased the release of MCP-1-6 by 2.5-, 3.6-, 4. 3-, and 4.5-fold, respectively, compared to fibroblasts exposed to serum-free culture medium alone. Challenge with titanium particles at concentrations of 0.075%, 0.150%, 0.300%, and 0.600% vol/vol increased the release of interleukin-6 by 2.6-, 6.4-, 9.6-, and 10. 0-fold, respectively, compared to fibroblasts exposed to serum-free culture medium alone at 24 h. Challenge with titanium particles at concentrations of 0.038%, 0.075%, 0.150%, 0.300%, and 0.600% vol/vol increased the release of MCP-1 by 2.9-, 3.1-, 5.8-, 5.4-, and 5. 8-fold, respectively, compared to fibroblasts exposed to serum-free culture medium alone. Pretreatment of fibroblasts with pertussis toxin inhibited the release of interleukin-6 and MCP-1 from PMMA and titanium particle challenged fibroblasts in a dose-dependent manner. PMMA particle induced fibroblast IL-6 release was inhibited by 23.6% and 35.3% with 20- and 200-ng/mL doses of pertussis toxin, respectively. Titanium particle induced fibroblast IL-6 release was inhibited by 48.2% and 56.3% with 20- and 200-ng/mL doses of pertussis toxin, respectively. PMMA particle-induced fibroblast MCP-1 release was inhibited by 36.0%, 50.4%, and 60.1% with 2-, 20- and 200-ng/mL doses of pertussis toxin, respectively. Titanium particle-induced fibroblast MCP-1 release was inhibited by 15.5%, 53.2%, and 64.6% with 2-, 20-, and 200-ng/mL doses of pertussis toxin, respectively. This study suggests that fibroblasts localized in periprosthetic membranes are a source of macrophage chemoattractant factors and proinflammatory mediators that may influence granuloma formation and lead to periprosthetic bone resorption. Furthermore, this study shows that G proteins are involved in particle-induced fibroblast activation, as evidenced by decrease levels of particle induced IL-6 and MCP-1 release following pertussis toxin treatment. (c) 2000 John Wiley & Sons, Inc.

  View details for PubMedID 10880077

• Socket retention: Staying in place ORTHOPEDICS Maloney, W. J. 2000; 23 (9): 965-966

  View details for Web of Science ID 000089386300018

  View details for PubMedID 11003101

• The bearing surface in total hip arthroplasty: evolution or revolution. Instructional course lectures Sharkey, P. F., Hozack, W. J., Dorr, L. D., Maloney, W. J., Berry, D. 2000; 49: 41-56

  Abstract

  Highly cross-linked polyethylenes represent a new class of polyethylenes that demonstrate dramatic improvements of wear characteristics in laboratory tests. Cross-linked polyethylenes can be manufactured by a number of methods, all of which lead to some changes in the physical properties of the polyethylene. The very limited clinical information about cross-linked polyethylenes available has been favorable. Cross-linked polyethylenes appear to hold promise as an alternative to conventional polyethylene and to hard-on-hard bearing surfaces, but much more clinical information will be required before they can be recommended for routine clinical use.

  View details for PubMedID 10829160

• Fixation, polyethylene wear, and pelvic osteolysis in primary total hip replacement 27th Meeting of the Hip-Society Maloney, W. J., Galante, J. O., Anderson, M., Goldberg, V., Harris, W. H., Jacobs, J., Kraay, M., Lachiewicz, P., Rubash, H. E., Schutzer, S., Woolson, S. T. SPRINGER. 1999: 157–64

  Abstract

  A multicenter retrospective review was performed analyzing 1081 primary total hip replacements in 944 patients using the Harris Galante-I cementless acetabular component with screw fixation. All patients were followed up for a minimum of 5 years with a mean followup of 81 months. Linear polyethylene wear averaged 0.11 mm/year (range, 0-0.86 mm/year). Pelvic osteolysis was seen in 25 patients (2.3%). Migration of the acetabular component was seen in four hips. A subgroup of patients was reanalyzed at a minimum followup of 10 years. The mean linear polyethylene wear rate remained 0.11 mm/year. In this group, only one socket had migrated. There was an association between wear rate and age. On average, younger patients had higher wear rates. The risk for having pelvic osteolysis develop and the need for revision surgery also was age-related. Twenty-two percent of hip replacements (15 hips) in patients younger than 50 years of age at the time of their index operation had pelvic osteolysis develop. In contrast, for patients older than 50 years of age at the time of surgery only 7.8% (eight hips) had osteolysis of the pelvis develop. For patients older than 70 years of age at the time of primary total hip replacement, none had pelvic osteolysis develop.

  View details for Web of Science ID 000084102600017

  View details for PubMedID 10611870

• Interleukin-4 inhibits granulocyte-macrophage colony-stimulating factor, interleukin-6, and tumor necrosis factor-alpha expression by human monocytes in response to polymethylmethacrylate particle challenge in vitro 44th Annual Meeting of the Orthopaedic-Research-Society Trindade, M. C., Nakashima, Y., Lind, M., Sun, D. H., Goodman, S. B., Maloney, W. J., Schurman, D. J., Smith, R. L. JOHN WILEY & SONS INC. 1999: 797–802

  Abstract

  The outcome of total joint arthroplasty is determined by biological events at the bone-implant interface. Macrophages phagocytose implant or wear debris at the interface and release proinflammatory mediators such as interleukins 1 and 6, tumor necrosis factor-alpha, and prostaglandin E2. These mediators are thought to contribute to the resorption of periprosthetic bone. Previous studies of tissues harvested from the bone-implant interface of failed orthopaedic implants demonstrated a possible role for two other cytokines, granulocyte-macrophage colony-stimulating factor and interleukin-4. The present study examined the effects of in vitro challenge with polymethylmethacrylate particles on the expression of granulocyte-macrophage colony-stimulating factor by primary human monocytes/macrophages and the role of interleukin-4 in regulating this expression. The polymethylmethacrylate particles caused a dose-dependent release of granulocyte-macrophage colony-stimulating factor at 48 hours. This release was accompanied by increased expression of interleukins 6 and 1beta and tumor necrosis factor-alpha. Release of the lysosomal enzyme hexosaminidase also increased in response to the particles. Interleukin-4 inhibited the expression of granulocyte-macrophage colony-stimulating factor, interleukin-6, and tumor necrosis factor-alpha at 48 hours in a dose-dependent manner. The data presented in this study confirm the hypothesis that interleukin-4 downregulates particle-induced activation of macrophages, as demonstrated by the decreased release of proinflammatory mediators.

  View details for PubMedID 10632444

• Interferon-gamma exacerbates polymethylmethacrylate particle-induced interleukin-6 release by human monocyte/macrophages in vitro JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Trindade, M. C., Lind, M., Goodman, S. B., Maloney, W. J., Schurman, D. J., Smith, R. L. 1999; 47 (1): 1-7

  Abstract

  Periprosthetic membranes commonly observed at sites of total joint implant loosening exhibit abundant macrophages and particulate debris. Macrophages phagocytose orthopedic debris and release the pro-inflammatory mediators interleukin-1, interleukin-6, tumor necrosis factor-alpha, and prostaglandin E2. In addition, other immunologic agents, such as interferon-gamma, are present in tissues harvested from the bone-implant interface of failed orthopedic implants. The present study examined the effects of interferon-gamma on polymethylmethacrylate (PMMA) particle-challenged monocyte/macrophages in vitro. The effects of interferon-gamma were determined by measuring interleukin-6 and tumor necrosis factor-alpha release by primary human monocyte/macrophages following exposure to PMMA particles. Exposure of the monocyte/macrophages to PMMA particles resulted in a dose-dependent release of interleukin-6 and tumor necrosis factor-alpha at 48 h. The interleukin-6 release in response to PMMA particle challenge was stimulated by 76% and 127% in the presence of 1.0 and 10.0 ng/mL of interferon-gamma, respectively. Interferon-gamma challenge alone did not alter interleukin-6 release relative to controls. In contrast to interleukin-6, interferon-gamma challenge stimulated tumor necrosis factor-alpha release in a dose-dependent manner. In the presence of particles, addition of 1.0 and 10.0 ng/mL of interferon-gamma resulted in 17% and 171% increases in the levels of tumor necrosis factor-alpha release, respectively, relative to cultures challenged solely with particles. Blocking antibody to IFN-gamma inhibited the effect of IFN-gamma on particle-induced interleukin-6 and tumor necrosis factor-alpha release. The data presented in this study demonstrate that the immunologic modulator interferon-gamma exacerbates monocyte/macrophage release of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in response to PMMA particle challenge in vitro.

  View details for PubMedID 10400874

• Reduced bone stress as predicted by composite beam theory correlates with cortical bone loss following cemented total hip arthroplasty JOURNAL OF ORTHOPAEDIC RESEARCH Silva, M. J., Reed, K. L., Robertson, D. D., Bragdon, C., Harris, W. H., Maloney, W. J. 1999; 17 (4): 525-531

  Abstract

  Clinical and experimental evidence suggest that periprosthetic bone loss following total hip arthroplasty is caused in part by stress-shielding. Changes in bone stress in the proximal femur following implantation can be estimated with use of composite beam theory. We hypothesized that the degree of stress-shielding predicted by beam theory correlates with the magnitude of bone loss following cemented total hip arthroplasty. We analyzed cross sections from the proximal femur of 13 patients who had undergone unilateral cemented total hip arthroplasty. A matching implant was inserted contralaterally, and the cross-sectional properties of the implant and bone and the bone density were determined. Bone loss was calculated on the basis of differences between contralateral (control) and ipsilateral (remodeled) sections and correlated to several beam-theory parameters calculated from the control sections: implant rigidity, bone rigidity, ratio of implant to bone rigidity, and predicted decrease in bone stress. All parameters except implant rigidity were significantly correlated with bone loss (p < 0.05). Parameters that included implant and bone properties were more strongly correlated with bone loss than were those based on bone properties alone. The predicted decrease in bone stress explained 50-60% of the variance in bone loss. The data also indicated that patients were not likely to lose substantial amounts of bone unless the reduction in bone stress exceeded a threshold value. Although limited by a small and heterogeneous sample, these results indicate that beam-theory predictions correlate with the degree of femoral resorption and should be investigated further as a means to identify patients at high risk for bone loss.

  View details for Web of Science ID 000082015400008

  View details for PubMedID 10459758

• Reexpression of type IIA procollagen by adult articular chondrocytes in osteoarthritic cartilage ARTHRITIS AND RHEUMATISM Aigner, T., Zhu, Y., Chansky, H. H., MATSEN, F. A., Maloney, W. J., Sandell, L. J. 1999; 42 (7): 1443-1450

  Abstract

  To test for the reexpression of the chondroprogenitor splice variant of the gene COL2A1, type IIA procollagen (containing a cysteine-rich NH2 propeptide), in adult articular chondrocytes in osteoarthritic (OA) joint disease.In situ hybridization and immunohistochemical localization were performed on normal and OA articular cartilage specimens. The presence of type IIA procollagen messenger RNA (mRNA) expression was confirmed by Northern blot analysis.In normal articular cartilage, no expression of mRNA or presence of type IIA procollagen was found. In OA articular cartilage, focally intense staining for type IIA protein was detected. Consistent with this, chondrocytes, particularly in the middle zones of articular cartilage, expressed type IIA procollagen mRNA. OA repair cartilage typically showed a broad zone of cells expressing type IIA mRNA and protein.Type IIA procollagen is reexpressed by adult articular chondrocytes in OA cartilage degeneration, indicating the potential reversion of the cells to a chondroprogenitor cellular phenotype. The absence of type IIA mRNA and protein in normal adult articular cartilage and its onset in the diseased state suggests type IIA procollagen as a marker of OA.

  View details for Web of Science ID 000081259400018

  View details for PubMedID 10403272

• Signaling pathways for tumor necrosis factor-alpha and interleukin-6 expression in human macrophages exposed to titanium-alloy particulate debris in vitro. journal of bone and joint surgery. American volume Nakashima, Y., Sun, D. H., Trindade, M. C., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 1999; 81 (5): 603-615

  Abstract

  Loosening of the implant after total joint arthroplasty remains a serious problem. The activation of macrophages by wear debris from implants, mediated by the release of cytokines that elicit bone resorption, may lead to loosening. The purpose of the present study was to elucidate the mechanisms of macrophage activation by titanium particles from the components of implants and to identify the signaling pathways involved in particle-mediated release of cytokines.Macrophages were isolated from mononuclear leukocytes obtained from healthy human donors and were exposed to titanium-alloy particles that had been obtained from periprosthetic membranes collected at revision total joint arthroplasties and then enzymatically prepared. The experimental protocols included examination of the effects of the inhibition of phagocytosis and the binding of antibodies to macrophage complement receptors on particle-induced macrophage activation. The release of the proinflammatory cytokines TNF-alpha (tumor necrosis factor-alpha) and IL-6 (interleukin-6) was used to assess macrophage activation. The signaling pathways involved in the induction of cytokine release were analyzed by identification of phosphorylated proteins with use of the Western blot technique and by translocation of the transcription factors nuclear factor-kappa B (NF-kappaB) and nuclear factor-interleukin-6 (NF-IL-6) into the nuclear protein fraction with use of electrophoretic mobility shift assays. The role of serine/threonine and tyrosine kinase pathways in the activation of nuclear factors and the release of cytokines was examined with use of selective pharmacological agents.Exposure of macrophages to titanium-alloy particles in vitro for forty-eight hours resulted in a fortyfold increase in the release of TNF-alpha and a sevenfold increase in the release of IL-6 (p<0.01). Phagocytosis of particles occurred in approximately 73 percent of the macrophages within one hour of exposure. Pretreatment of the macrophages with cytochalasin B reduced phagocytosis by 95 percent but did not reduce the release of TNF-alpha or IL-6. Thus, phagocytosis of particles was not necessary for induction of the release of TNF-alpha or IL-6 in the cultured macrophages. Ligation of the macrophage CD11b/CD18 receptors by integrin-specific antibodies also increased the release of TNF-alpha and IL-6. Antibodies to CD11b/ CD18 receptors (macrophage Mac-1 receptors) reduced phagocytosis of particles by 50 percent (p<0.05). (The CD11b/CD18 macrophage receptor is the macrophage receptor for the complement component CR3bi. The CD11b/CD18 macrophage receptor can also bind to ICAM-1 and ICAM-2. CD is the abbreviation for cluster of differentiation, and ICAM is the abbreviation for intercellular adhesion molecule.) Inhibition of phagocytosis was not accompanied by a decrease in the release of TNF-alpha and IL-6. Blocking RNA synthesis with actinomycin D or preventing protein synthesis with cycloheximide abolished or decreased particle-induced release of TNF-alpha and IL-6 from the macrophages. Macrophage release of TNF-alpha and IL-6 in response to particles coincided with increased tyrosine phosphorylation and mitogen-activated protein kinase activation. Inhibition of tyrosine and serine/threonine kinase activity decreased the particle-induced release of cytokines. Exposure of macrophages to either titanium-alloy particles or to antibodies to the receptor proteins CD11b and CD18 for thirty minutes activated the transcription factors NF-kappaB and NF-IL-6. Inhibition of particle phagocytosis did not block activation of the transcription factors. However, inhibition of tyrosine and serine/threonine kinase activity decreased the activation of NF-kappaB and NF-IL-6.These data suggest that particle induced macrophage release of TNF-alpha and IL-6 does not require phagocytosis but is dependent on tyrosine and serine/threonine kinase activity culminating in activation of

  View details for PubMedID 10360689

• Signaling pathways for tumor necrosis factor-alpha and interleukin-6 expression in human macrophages exposed to titanium-alloy particulate debris in vitro JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Nakashima, Y., Sun, D. H., Trindade, M. C., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 1999; 81A (5): 603-615

  Abstract

  Loosening of the implant after total joint arthroplasty remains a serious problem. The activation of macrophages by wear debris from implants, mediated by the release of cytokines that elicit bone resorption, may lead to loosening. The purpose of the present study was to elucidate the mechanisms of macrophage activation by titanium particles from the components of implants and to identify the signaling pathways involved in particle-mediated release of cytokines.Macrophages were isolated from mononuclear leukocytes obtained from healthy human donors and were exposed to titanium-alloy particles that had been obtained from periprosthetic membranes collected at revision total joint arthroplasties and then enzymatically prepared. The experimental protocols included examination of the effects of the inhibition of phagocytosis and the binding of antibodies to macrophage complement receptors on particle-induced macrophage activation. The release of the proinflammatory cytokines TNF-alpha (tumor necrosis factor-alpha) and IL-6 (interleukin-6) was used to assess macrophage activation. The signaling pathways involved in the induction of cytokine release were analyzed by identification of phosphorylated proteins with use of the Western blot technique and by translocation of the transcription factors nuclear factor-kappa B (NF-kappaB) and nuclear factor-interleukin-6 (NF-IL-6) into the nuclear protein fraction with use of electrophoretic mobility shift assays. The role of serine/threonine and tyrosine kinase pathways in the activation of nuclear factors and the release of cytokines was examined with use of selective pharmacological agents.Exposure of macrophages to titanium-alloy particles in vitro for forty-eight hours resulted in a fortyfold increase in the release of TNF-alpha and a sevenfold increase in the release of IL-6 (p<0.01). Phagocytosis of particles occurred in approximately 73 percent of the macrophages within one hour of exposure. Pretreatment of the macrophages with cytochalasin B reduced phagocytosis by 95 percent but did not reduce the release of TNF-alpha or IL-6. Thus, phagocytosis of particles was not necessary for induction of the release of TNF-alpha or IL-6 in the cultured macrophages. Ligation of the macrophage CD11b/CD18 receptors by integrin-specific antibodies also increased the release of TNF-alpha and IL-6. Antibodies to CD11b/ CD18 receptors (macrophage Mac-1 receptors) reduced phagocytosis of particles by 50 percent (p<0.05). (The CD11b/CD18 macrophage receptor is the macrophage receptor for the complement component CR3bi. The CD11b/CD18 macrophage receptor can also bind to ICAM-1 and ICAM-2. CD is the abbreviation for cluster of differentiation, and ICAM is the abbreviation for intercellular adhesion molecule.) Inhibition of phagocytosis was not accompanied by a decrease in the release of TNF-alpha and IL-6. Blocking RNA synthesis with actinomycin D or preventing protein synthesis with cycloheximide abolished or decreased particle-induced release of TNF-alpha and IL-6 from the macrophages. Macrophage release of TNF-alpha and IL-6 in response to particles coincided with increased tyrosine phosphorylation and mitogen-activated protein kinase activation. Inhibition of tyrosine and serine/threonine kinase activity decreased the particle-induced release of cytokines. Exposure of macrophages to either titanium-alloy particles or to antibodies to the receptor proteins CD11b and CD18 for thirty minutes activated the transcription factors NF-kappaB and NF-IL-6. Inhibition of particle phagocytosis did not block activation of the transcription factors. However, inhibition of tyrosine and serine/threonine kinase activity decreased the activation of NF-kappaB and NF-IL-6.These data suggest that particle induced macrophage release of TNF-alpha and IL-6 does not require phagocytosis but is dependent on tyrosine and serine/threonine kinase activity culminating in activation of

  View details for Web of Science ID 000080412800003

• Induction of macrophage C-C chemokine expression by titanium alloy and bone cement particles. journal of bone and joint surgery. British volume Nakashima, Y., Sun, D. H., Trindade, M. C., Chun, L. E., Song, Y., Goodman, S. B., Schurman, D. J., Maloney, W. J., Smith, R. L. 1999; 81 (1): 155-162

  Abstract

  Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1alpha), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1alpha expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1alpha in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1alpha were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1alpha inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.

  View details for PubMedID 10068024

• A new classification system for the management of acetabular osteolysis after total hip arthroplasty. Instructional course lectures Rubash, H. E., Sinha, R. K., Paprosky, W., Engh, C. A., Maloney, W. J. 1999; 48: 37-42

  View details for PubMedID 10098026

• Induction of macrophage C-C chemokine expression by titanium alloy and bone cement particles JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Nakashima, Y., Sun, D. H., Trindade, M. C., Chun, L. E., Song, Y., Goodman, S. B., Schurman, D. J., Maloney, W. J., Smith, R. L. 1999; 81B (1): 155-162

  Abstract

  Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1alpha), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1alpha expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1alpha in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1alpha were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1alpha inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.

  View details for Web of Science ID 000080737900033

• Expression of inflammatory mediators by human macrophages in response to particulate debris in vitro 28th Annual Meeting of the Japanese-Society-for-Replacement-Arthroplasty Nakashima, Y., Sun, D. H., Trindade, M., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L., Ushijima, M., Iwamoto, Y. SPRINGER-VERLAG TOKYO. 1999: 65–75

  View details for Web of Science ID 000086113200007

• Adhesion and reliability of interfaces in cemented total joint arthroplasties JOURNAL OF ORTHOPAEDIC RESEARCH Ohashi, K. L., Romero, A. C., McGowan, P. D., Maloney, W. J., Dauskardt, R. H. 1998; 16 (6): 705-714

  Abstract

  Debonding of the prosthetic/polymethylmethacrylate interface has been implicated in the initial failure process of cemented total hip arthroplasties. However, little quantitative understanding of the debonding process, as well as of the optimum interface morphology for enhanced resistance to debonding, exists. Accordingly, a fracture-mechanics approach has been used in which adhesion at the interface is characterized in terms of the interface fracture energy, G (J/m2), and shown to be a strong function of the morphology, debonding length, and loading mode of the interface. Double-cantilever-beam and four-point-flexure fracture-mechanics samples containing four clinically relevant prosthetic surface preparations were prepared to survey a range of interface roughness and loading modes. Adhesion at the interface could not be characterized with a single-valued material property but was found to exhibit resistance-curve behavior in which resistance to debonding increased with both the initial debond extension and the roughness of the interface. Values of debonding initiation, Go, were relatively insensitive to the roughness of the surface and the loading mode, whereas steady-state fracture resistance of the interface, Gss, increased significantly with the roughness and shear loading of the interface. These quantitative results suggest that debonding of the prosthetic/polymethylmethacrylate interface may be primarily attributed to surface interactions such as interlocking and the pullout of rough asperities that occur behind the debond tip. A simple mechanics analysis of such interactions was performed and revealed increases in the fracture resistance of the interface that were consistent with experimentally measured values.

  View details for Web of Science ID 000077786300011

  View details for PubMedID 9877395

• Importance of a thin cement mantle - Autopsy studies of eight hips 26th Open Scientific Meeting of the Hip Society Kawate, K., Maloney, W. J., Bragdon, C. R., Biggs, S. A., Jasty, M., Harris, W. H. SPRINGER. 1998: 70–76

  Abstract

  The question whether thin cement mantles around cemented femoral components led to an increased frequency of cracks in the cement was asked. Microscopically, multiple cross sections of eight femurs retrieved at autopsy from clinically successful total hip replacements after prolonged in vivo service containing well fixed Harris Design 2 cemented femoral components were studied. None of the components were loose by radiographic criteria. All were fixed solidly when loaded in vitro in simulated stair climbing and gait, as assessed by high resolution micromotion sensors. The specimens were sectioned transversely at 5-mm increments. The cross sections were examined under a dissecting microscope at x 100. A thin mantle arbitrarily was defined as a mantle of less than 1 mm in thickness. The analysis of the contact radiographs showed that the routine anteroposterior and lateral radiographs underestimated the prevalence of thin cement mantles and mantle defects. Although overall on all the cross sections 9% of the aggregated cement mantles was classified as having thin cement, 92 of the 101 cement cracks occurred in areas of the mantles that were less than 1 mm thick.

  View details for Web of Science ID 000077148700008

  View details for PubMedID 9917592

• Osteolysis in association with a total hip arthroplasty with ceramic bearing surfaces JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Yoon, T. R., Rowe, S. M., Jung, S. T., Seon, K. J., Maloney, W. J. 1998; 80A (10): 1459-1468

  View details for Web of Science ID 000076664500007

• Cemented femoral component surface finish mechanics 26th Open Scientific Meeting of the Hip Society Crowninshield, R. D., Jennings, J. D., Laurent, M. L., Maloney, W. J. SPRINGER. 1998: 90–102

  Abstract

  A cemented femoral component's surface finish may influence implant function through variations in cement adhesion and abrasion properties. Morphologic characterization of historic and current femoral hip prosthesis surface finishes show greater than x 20 range in implant roughness. Early implants typically had relatively smooth surfaces, whereas many of the more recent implants have rougher surface finishes. Smoother implant surfaces have lower cement-metal interface fixation strength, whereas rougher surfaces have greater fixation strength. With interface motion, the smoother surfaces are less abrasive of bone cement, whereas rougher implant surfaces are more abrasive. Because of enhanced bone cement attachment, rougher implant surfaces may have a lower probability of interface motion, while at the same time, a higher debris generation consequence if motion occurs. In contrast, smoother implant surfaces may have a higher probability of interface motion with a lower debris generating consequence of that motion. The prolonged use of cemented total hip replacement may be approached by either extending the duration of implant function after cement-metal interface loosening with smooth surfaced implants or, in contrast, by extending the duration of cement-metal interface adhesion with rougher surfaced implants.

  View details for Web of Science ID 000077148700010

  View details for PubMedID 9917594

• Osteolysis in association with a total hip arthroplasty with ceramic bearing surfaces. journal of bone and joint surgery. American volume Yoon, T. R., Rowe, S. M., Jung, S. T., Seon, K. J., Maloney, W. J. 1998; 80 (10): 1459-1468

  Abstract

  The results of 103 total hip arthroplasties performed with insertion of a ceramic femoral head and acetabular component in ninety-six patients were reviewed to determine the radiographic prevalence of osteolysis. After a mean duration of follow-up of ninety-two months (range, sixty to 125 months), femoral osteolysis was observed in twenty-three hips (22 per cent), in one of two distinct patterns: linear osteolysis (twelve hips) or scalloping expansile-type osteolysis (eleven hips). The most common locations of osteolysis in the femur were in zones I and VII as described by Gruen et al. Serial radiographs demonstrated that the extent of the osteolysis progressed over time. Osteolysis of the pelvis, noted in forty-nine hips, was always associated with migration of the acetabular socket. No focal osteolysis was observed in association with the stable sockets. Ten patients (ten hips) had a revision because of loosening and migration of the acetabular component. In three of these patients, the femoral stem also was revised. Gross examination revealed evidence of wear of the ceramic bearing surface in all ten patients. Scanning electron microscopy showed cracking and wear marks on the weight-bearing surface. Histological evaluation of the tissue in the periprosthetic membrane demonstrated abundant ceramic wear particles. The interface membrane was composed of a vascularized fibrous connective tissue with macrophages. Ultrastructurally, the macrophages contained numerous phagosomes of various sizes, with electron-dense material within the cytoplasm of the cell. The mean size of the ceramic particles, as determined with scanning electron microscopy, was 0.71 micrometer (range, 0.13 to 7.20 micrometers). This study supports the concept that ceramic wear particles can stimulate a foreign-body response and periprosthetic osteolysis.

  View details for PubMedID 9801214

• Effects of serum protein opsonization on cytokine release by titanium-alloy particles JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Maloney, W. J., Sun, D. H., Nakashima, Y., James, R., Smith, R. L. 1998; 41 (3): 371-376

  Abstract

  This study tested whether macrophages respond differently to retrieved titanium-alloy particles than they do to machined titanium-alloy particles and assessed whether pretreatment of machined titanium-alloy particles with human serum would influence macrophage activation and cytokine release in vitro. Human monocyte/macrophages were isolated from normal healthy donors and exposed to increasing concentrations of machined and retrieved titanium-alloy particles. The profile of cytokine release was determined by commercially available ELISA kits. Machined titanium-alloy particles were opsonized with human serum and added to macrophage cultures. Serum protein binding was confirmed by SDS-PAGE analysis. The results showed that machined titanium-alloy particles and retrieved titanium-alloy particles stimulate a similar level of cytokine release when tested at comparable concentrations. Opsonization of the machined particles with human serum increased the macrophage release of cytokines in the first 12 h after exposure compared to nonopsonized particles. At 24 h, the opsonized particles stimulated significantly higher levels of cytokine release, but only at the greatest particle concentrations. This study demonstrates that machined titanium alloy induces a metabolic response in macrophages similar to that of titanium-alloy particles retrieved from failed total hip arthroplasty. In addition, these data show that serum protein binding to orthopedic biomaterial debris alters the macrophage reaction to the particles.

  View details for Web of Science ID 000074523300005

  View details for PubMedID 9659605

• Prediction of postoperative knee flexion in Insall-Burstein II total knee arthroplasty CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Schurman, D. J., Matityahu, A., Goodman, S. B., Maloney, W., Woolson, S., Shi, H., Bloch, D. A. 1998: 175-184

  Abstract

  Postoperative knee flexion in patients undergoing Insall-Burstein-II total knee arthroplasty at 2 years was evaluated regarding two basic questions: what groups of patients gain or lose the most flexion and what groups of patients have the best or worst postoperative flexion. Thirteen preoperative variables (maximum flexion, flexion arc, tibiofemoral angle, quadriceps strength, extensor lag, Knee Society score, Knee Society patient assessment, gender, age, height, weight, diagnosis, and surgeon) and four postoperative variable (leg length change, tibiofemoral angle, distance from patella to the joint line, and the tibial prosthesis anteroposterior translation on a lateral radiograph) were used in an attempt to explain postoperative flexion. The analysis was performed on 164 consecutive Insall-Burstein-II total knees in which the data were gathered prospectively on a time oriented medical record database. A regression tree analysis was used to identify several groups of patients, characterized by preoperative factor values, who had markedly above average performance on postoperative flexion. The preoperative factors identified include preoperative flexion, flexion arc, tibiofemoral angle, extensor lag, diagnosis, and age. The only postoperative variable of significance was tibiofemoral angle. Among the potential determinants of postoperative flexion that failed to appear predictive were the Knee Society scores and surgeon. Preoperative flexion is known to be a critical determinant of postoperative flexion in total knee replacement. However, in the current study, preoperative flexion accounted for only half of the difference between the best (122 degrees) and the worst (88 degrees) group, as determined with regression tree analysis.

  View details for PubMedID 9728172

• Induction of matrix metalloproteinase expression in human macrophages by orthopaedic particulate debris in vitro. journal of bone and joint surgery. British volume Nakashima, Y., Sun, D. H., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 1998; 80 (4): 694-700

  Abstract

  We exposed human macrophages isolated from the peripheral blood of healthy donors to metal and bone-cement particles from 0.2 to 10 microm in size. Zymography showed that macrophages exposed to titanium alloy and polymethylmethacrylate (PMMA) particles released a 92- and 72-kDa gelatinase in a dose- and time-dependent manner. Western immunoblotting confirmed that the 92- and 72-kDa gelatinolytic activities corresponded to matrix metalloproteinase-9 and matrix metalloproteinase-2 (MMP-9, MMP-2), respectively. Western immunoblotting also indicated that titanium alloy and PMMA particles increased the release of MMP-1. Northern blotting showed elevated mRNA signal levels for MMP-1, MMP-2, and MMP-9 after exposure to both types of particle. Collagenolytic activity also increased in the macrophage culture medium in response to both types of particle. Our findings support the hypothesis that macrophages release MMPs in proportion to the amount of particulate debris within periprosthetic tissues.

  View details for PubMedID 9699840

• Induction of matrix metalloproteinase expression in human macrophages by orthopaedic particulate debris in vitro JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Nakashima, Y., Sun, D. H., Maloney, W. J., Goodman, S. B., Schurman, D. J., Smith, R. L. 1998; 80B (4): 694-700

  Abstract

  We exposed human macrophages isolated from the peripheral blood of healthy donors to metal and bone-cement particles from 0.2 to 10 microm in size. Zymography showed that macrophages exposed to titanium alloy and polymethylmethacrylate (PMMA) particles released a 92- and 72-kDa gelatinase in a dose- and time-dependent manner. Western immunoblotting confirmed that the 92- and 72-kDa gelatinolytic activities corresponded to matrix metalloproteinase-9 and matrix metalloproteinase-2 (MMP-9, MMP-2), respectively. Western immunoblotting also indicated that titanium alloy and PMMA particles increased the release of MMP-1. Northern blotting showed elevated mRNA signal levels for MMP-1, MMP-2, and MMP-9 after exposure to both types of particle. Collagenolytic activity also increased in the macrophage culture medium in response to both types of particle. Our findings support the hypothesis that macrophages release MMPs in proportion to the amount of particulate debris within periprosthetic tissues.

  View details for Web of Science ID 000074909800030

• Cellular profile and cytokine production at prosthetic interfaces. Study of tissues retrieved from revised hip and knee replacements. journal of bone and joint surgery. British volume Goodman, S. B., Huie, P., Song, Y., Schurman, D., Maloney, W., Woolson, S., Sibley, R. 1998; 80 (3): 531-539

  Abstract

  The tissues surrounding 65 cemented and 36 cementless total joint replacements undergoing revision were characterised for cell types by immunohistochemistry and for cytokine expression by in situ hybridisation. We identified three distinct groups of revised implants: loose implants with ballooning radiological osteolysis, loose implants without osteolysis, and well-fixed implants. In the cemented series, osteolysis was associated with increased numbers of macrophages (p = 0.0006), T-lymphocyte subgroups (p = 0.03) and IL-1 (p = 0.02) and IL-6 (p = 0.0001) expression, and in the cementless series with increased numbers of T-lymphocyte subgroups (p = 0.005) and increased TNF alpha expression (p = 0.04). For cemented implants, the histological, histochemical and cytokine profiles of the interface correlated with the clinical and radiological grade of loosening and osteolysis. Our findings suggest that there are different biological mechanisms of loosening and osteolysis for cemented and cementless implants. T-lymphocyte modulation of macrophage function may be an important interaction at prosthetic interfaces.

  View details for PubMedID 9619952

• Cellular profile and cytokine production at prosthetic interfaces - Study of tissues retrieved from revised hip and knee replacements JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Goodman, S. B., Huie, P., Song, Y., Schurman, D., Maloney, W., Woolson, S., Sibley, R. 1998; 80B (3): 531-539

  Abstract

  The tissues surrounding 65 cemented and 36 cementless total joint replacements undergoing revision were characterised for cell types by immunohistochemistry and for cytokine expression by in situ hybridisation. We identified three distinct groups of revised implants: loose implants with ballooning radiological osteolysis, loose implants without osteolysis, and well-fixed implants. In the cemented series, osteolysis was associated with increased numbers of macrophages (p = 0.0006), T-lymphocyte subgroups (p = 0.03) and IL-1 (p = 0.02) and IL-6 (p = 0.0001) expression, and in the cementless series with increased numbers of T-lymphocyte subgroups (p = 0.005) and increased TNF alpha expression (p = 0.04). For cemented implants, the histological, histochemical and cytokine profiles of the interface correlated with the clinical and radiological grade of loosening and osteolysis. Our findings suggest that there are different biological mechanisms of loosening and osteolysis for cemented and cementless implants. T-lymphocyte modulation of macrophage function may be an important interaction at prosthetic interfaces.

  View details for Web of Science ID 000073647500031

• Deep venous thrombosis prophylaxis for knee replacement: warfarin and pneumatic compression. American journal of orthopedics (Belle Mead, N.J.) Woolson, S. T., Robinson, R. K., Khan, N. Q., Roqers, B. S., Maloney, W. J. 1998; 27 (4): 299-304

  Abstract

  A prospective study of the prevalence of proximal deep venous thrombosis in total knee replacement patients who had prophylaxis for thrombosis with a combination of low-dose warfarin and intermittent pneumatic compression was done. Two hundred and ninety-seven patients who underwent 377 consecutive total knee replacements were studied. All patients were treated with low-dose warfarin and intermittent pneumatic compression using thigh-high sleeves. Surveillance for proximal thrombosis was done by duplex ultrasonography. Proximal thrombosis was detected in 19 patients, for a prevalence of 5%. There were 3 patients who had a major bleeding complication, for a prevalence of 0.9% for the 337 procedures performed. Although there was no concurrent control group of patients treated with another means of prophylaxis to compare with these patients, the low prevalence of proximal thrombosis and the low risk of major bleeding complications that was found compares well with recent reports on the effectiveness and safety of low-molecular-weight heparin.

  View details for PubMedID 9586729

• Factor V Leiden and the risk of proximal venous thrombosis after total hip arthroplasty JOURNAL OF ARTHROPLASTY Woolson, S. T., Zehnder, J. L., Maloney, W. J. 1998; 13 (2): 207-210

  Abstract

  Deep vein thrombosis (DVT) remains a major cause of morbidity in patients undergoing total hip arthroplasty (THA). Despite postoperative DVT prophylaxis, 20-50% of THA patients still develop DVT. Currently, there is no accurate way of predicting which patients will develop DVT despite standard prophylaxis. The presence of factor V Leiden is the most common cause of inherited DVT risk. It has been postulated that patients who have factor V Leiden and are subjected to thrombogenic stressors such as THA would have an increased risk of thrombosis. The factor V Leiden genotype of 36 patients who developed proximal DVT after surgery and 45 control patients who had THA but did not develop DVT was determined. All patients had had prophylaxis against thrombosis using intermittent pneumatic compression alone or in combination with warfarin or aspirin. Surveillance for proximal DVT was performed on all patients prior to discharge by duplex ultrasound. The 2 groups were similar in age, sex, and type of operation. Three of 36 study patients who had developed DVT (8%) and 2 of 45 control patients who had not developed DVT (4%) were heterozygotes for factor V Leiden; these prevalences were not statistically different. Heterozygosity for factor V Leiden is not associated with DVT prophylaxis failure in patients undergoing THA.

  View details for Web of Science ID 000072498700014

  View details for PubMedID 9526216

• Osteolysis: Cause and effect 64th Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons Sinha, R. K., Shanbhag, A. S., Maloney, W. J., Hasselman, C. T., Rubash, H. E. AMER ACAD ORTHOPAEDIC SURGEONS. 1998: 307–320

  View details for Web of Science ID 000074947000036

  View details for PubMedID 9571432

• Osteolysis: Surgical treatment 64th Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons Rubash, H. E., Sinha, R. K., Maloney, W. J., Paprosky, W. G. AMER ACAD ORTHOPAEDIC SURGEONS. 1998: 321–329

  View details for Web of Science ID 000074947000037

  View details for PubMedID 9571433

• Fatigue fracture of a forged cobalt-chromium-molybdenum femoral component inserted with cement. A report of ten cases. journal of bone and joint surgery. American volume Woolson, S. T., Milbauer, J. P., Bobyn, J. D., Yue, S., Maloney, W. J. 1997; 79 (12): 1842-1848

  Abstract

  Ten patients who had had a total hip replacement with a forged cobalt-chromium-molybdenum femoral prosthesis (Precoat or Precoat Plus) inserted with cement were seen with a fatigue fracture of the stem an average of fifty months (range, nineteen to seventy-four months) postoperatively. The average age of the patients was sixty-one years (range, forty-three to seventy-three years), and the average weight was ninety-six kilograms (range, seventy to 130 kilograms). Eight patients had had a primary total hip replacement, and two had had a revision; all of the acetabular components had been inserted without cement. Radiographs that had been made before the fracture were available for four of the eight hips that had had a primary replacement; all four had radiographic evidence of debonding of the cement mantle from the proximal end of the stem. This probably caused exaggerated cantilever bending stresses on the proximal aspect of the stem as the distal end of the stem was well fixed. The radiographs of both hips that had had a revision demonstrated a non-union of the greater trochanter, which had resulted in separation at the cement-bone interface at the proximal portion of the femur before the fracture. Scanning electron micrographs of five of the ten fractured prostheses demonstrated a fatigue fracture that began near the anterolateral corner of the prosthesis, through characters that had been etched on the implant with a laser. Metallurgical analysis indicated subsurface voids or inclusions, or both, immediately under the region that had been etched. This finding is consistent with thermal changes to the microstructure of the alloy that probably caused a focal reduction in the material strength. A high proportion (seven) of the ten stems had a poor cement mantle. Also, of the seven small stems that were used, six had been implanted in patients who weighed more than eighty kilograms, so there was relative undersizing of the prostheses. Early debonding of the proximal end of a Precoat femoral prosthesis from the cement mantle may occur as a result of a thin cement mantle, leading to loosening and possibly to early fatigue fracture of the stem if the distal portion of the stem remains solidly fixed in the distal portion of the cement column. On the basis of our experience, we recommend that patients who have radiographic evidence of a debonded Precoat femoral component should be informed of the risk of fatigue fracture of the stem and be followed closely even though there may be no symptoms of loosening of the femoral component.

  View details for PubMedID 9409798

• Fatigue fracture of a forged cobalt-chromium-molybdenum femoral component inserted with cement - A report of ten cases JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Woolson, S. T., Milbauer, J. P., Bobyn, J. D., Yue, S., Maloney, W. J. 1997; 79A (12): 1842-1848

  View details for Web of Science ID 000071006800010

• Treatment of pelvic osteolysis associated with a stable acetabular component inserted without cement as part of a total hip replacement JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Herzwurm, P., Paprosky, W., Rubash, H. E., Engh, C. A. 1997; 79A (11): 1628-1634

  View details for Web of Science ID A1997YH18500003

• Treatment of pelvic osteolysis associated with a stable acetabular component inserted without cement as part of a total hip replacement. journal of bone and joint surgery. American volume Maloney, W. J., Herzwurm, P., Paprosky, W., Rubash, H. E., Engh, C. A. 1997; 79 (11): 1628-1634

  Abstract

  Thirty-five patients who had had a primary total hip replacement with a porous-coated acetabular component inserted without cement had a revision procedure to treat pelvic osteolysis. The mean age at the time of the revision operation was forty-nine years (range, twenty-nine to eighty-five years). Forty-six distinct pelvic osteolytic lesions were noted radiographically around the thirty-five cups. These lesions ranged in size from 0.5 by 0.5 centimeter to 6.3 by 2.7 centimeters (mean, 2.6 by 1.7 centimeters). Fourteen of the thirty-five patients had no or only slight occasional pain at the time of diagnosis of the pelvic osteolysis, fifteen patients had pain attributed to a loose femoral component, one had pain related to a spontaneous fracture of the greater trochanter, and one had pain related to recurrent subluxation. The remaining four patients had pain in the groin despite radiographically stable implants. All of the metal-backed porous-coated acetabular components were stable according to the preoperative radiographs, and the stability was confirmed at the time of the revision. The metal shell was left in place and the acetabular liner was exchanged in all thirty-five patients. The osteolytic lesions were debrided, and thirty-four of the forty-six lesions were filled with allograft bone chips. The patients were evaluated a minimum of two years (range, two to five years; mean, 3.3 years) after the revision operation, and all thirty-five sockets were found to be radiographically stable. The bone grafts appeared to have consolidated, and none of the osteolytic defects had progressed. One-third of the lesions were no longer visible on radiographs, regardless of whether or not they had been filled with bone graft. The remaining lesions had decreased in size. It appears that, in the short-term, exchange of the liner and debridement of the granuloma, with or without use of allograft bone chips in the osteolytic defect, is a reasonable alternative to revision of the socket provided that the metal shell is solidly fixed at the time of the revision operation. If the metal shell has been markedly damaged by the femoral head, the locking mechanism for the polyethylene liner is not intact, or a satisfactory replacement liner is not available, then revision of the porous-coated acetabular component is indicated. These results must be considered preliminary. Since osteolysis may take several years to redevelop after a revision, additional follow-up is required.

  View details for PubMedID 9384421

• Loosening and osteolysis of cemented joint arthroplasties - A biologic spectrum CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Goodman, S. B., Huie, P., Song, Y., Lee, K., Doshi, A., Rushdieh, B., Woolson, S., Maloney, W., Schurman, D., Sibley, R. 1997: 149-163

  Abstract

  The purpose of this study was to characterize the cell types (using immunohistochemistry) and cytokine expression (using in situ hybridization) of tissues surrounding well fixed and loose cemented prostheses undergoing revision. Clinical and radiographic data were gathered prospectively for a series of cemented total joint replacements undergoing revision. Three groups were identified: (1) loose implants with osteolysis (10 specimens), (2) loose implants without osteolysis (11 specimens), and (3) well fixed implants (7 specimens). At surgery, a specimen was harvested from the bone cement interface. Immunohistochemical staining was performed using monoclonal antibodies to identify macrophages and lymphocyte subgroups. Human antisense probes were selected to identify the mRNA for specific cytokines using in situ hybridization. The percentage of positively staining cells was determined for each antibody or probe using a grid counting technique. Tissues from loose cemented prostheses with osteolysis contained significantly greater numbers of macrophages and T lymphocytes compared with tissues from loose and well fixed cemented prostheses without osteolysis. The number of interleukin-1 and interleukin-6 positive cells was highest in specimens with osteolysis and lowest in specimens from well fixed prostheses. These cytokines modulate the growth and differentiation of cells in the immune system and the monocyte and macrophage system and mediate the remodeling of bone and mesenchymal tissues. Specific cell populations and cytokine profiles appear to be involved in periprosthetic osteolysis; this information may be useful in planning strategies for prevention and treatment.

  View details for PubMedID 9137186

• Osteoarthritis: Differential expression of matrix metalloproteinase-9 mRNA in nonfibrillated and fibrillated cartilage 40th Annual Meeting of the Orthopaedic-Research-Society Tsuchiya, K., Maloney, W. J., Vu, T., Hoffman, A. R., Huie, P., Sibley, R., Schurman, D. J., Smith, R. L. WILEY-BLACKWELL. 1997: 94–100

  Abstract

  Expression of matrix metalloproteinase-9 mRNA in osteoarthritic and normal cartilage was analyzed using reverse transcription-polymerase chain reaction and in situ hybridization. Fifty-four osteoarthritic cartilage samples were obtained from 24 patients undergoing total knee arthroplasty. Sixteen normal cartilage samples were obtained from non-osteoarthritic knees of four autopsy cases. With normal cartilage, reverse transcription-polymerase chain reaction analysis for matrix metalloproteinase-9 mRNA showed that chondrocytes exhibited only a trace signal. In analysis of osteoarthritic cartilage, chondrocytes of moderately and severely fibrillated cartilage exhibited a 73-fold and 110-fold increase in matrix metalloproteinase-9 mRNA signal, respectively, relative to normal cartilage. Chondrocytes of nonfibrillated osteoarthritic cartilage exhibited a 6-fold increase (p < 0.02) in matrix metalloproteinase-9 mRNA signal relative to normal cartilage. Analysis of matrix metalloproteinase-9 mRNA expression in fresh-frozen sections of normal and osteoarthritic cartilage by in situ hybridization confirmed these results. This study showed that reverse transcription-polymerase chain reaction provides a sensitive index of mRNA levels in normal and osteoarthritic cartilage samples and suggests that increased expression of matrix metalloproteinase-9 precedes fibrillation of cartilage in the development of osteoarthritis.

  View details for Web of Science ID A1997WL95000013

  View details for PubMedID 9066532

• The implant-bone interface and the effects of particulate debris 2nd International Workshop on Osseointegration in Skeletal Reconstruction and Joint Replacement Maloney, W. J., Engh, C. A. QUINTESSENCE PUBL CO INC. 1997: 203–213

  View details for Web of Science ID A1997BH29U00017

• The fibrous tissue interface surrounding well-fixed, revised, cementless acetabular components for hip replacement Symposium on Modularity of Orthopedic Implants Goodman, S. B., Huie, P., Song, Y., OConnor, M., Woolson, S. T., Maloney, W. J., Schurman, D. J., Sibley, R. AMERICAN SOCIETY TESTING AND MATERIALS. 1997: 21–32

  View details for Web of Science ID A1997BH43N00002

• Skeletal response to well fixed femoral components inserted with and without cement CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Sychterz, C., Bragdon, C., McGovern, T., Jasty, M., Engh, C. A., Harris, W. H. 1996: 15-26

  View details for Web of Science ID A1996WA38000003

• The Otto Aufranc Award. Skeletal response to well fixed femoral components inserted with and without cement. Clinical orthopaedics and related research Maloney, W. J., Sychterz, C., Bragdon, C., McGovern, T., Jasty, M., Engh, C. A., Harris, W. H. 1996: 15-26

  Abstract

  Previous studies evaluating femoral remodeling after total hip arthroplasty have used clinical radiographs and dual energy xray absorptiometry. Limitation of these techniques make it impossible to quantify the magnitude of bone loss in terms of cortical thinning and cortical bone area and bone mineral density changes. Femoral cortical bone remodeling after cemented and cementless replacement was quantified and possible determinants of bone remodeling in terms of clinical and radiographic variables were evaluated. Forty-eight anatomic specimen femora from 24 patients with unilateral cemented and cementless hip replacements were analyzed. Cortical thickness, cortical bone area, and bone mineral density was assessed in 4 quadrants at 5 discrete levels. The maximum cortical bone loss by level was at the middle section for the cemented femurs and at the midproximal and middle sections for the cementless femurs. However, if one examines individual quadrants, the proximal medial cortex still represents the specific region of maximal bone loss for both types of implant fixation. The posterior cortex had substantially more bone loss, even in the diaphyseal levels, than had been previously appreciated. A strong correlation was noted between the bone mineral density of the control femur and the percentage decrease of bone mineral density in the remodeled femur. Based on this data, it seems that the less dense the bone is before hip replacement surgery, the greater the extent of bone loss after total hip arthroplasty regardless of the fixation type.

  View details for PubMedID 8981879

• Osteoblast adhesion to orthopaedic implant alloys: Effects of cell adhesion molecules and diamond-like carbon coating 21st Annual Meeting of the Society-for-Biomaterials Kornu, R., Maloney, W. J., Kelly, M. A., Smith, R. L. JOHN WILEY & SONS INC. 1996: 871–77

  Abstract

  In total joint arthroplasty, long-term outcomes depend in part on the biocompatibility of implant alloys. This study analyzed effects of surface finish and diamond-like carbon coating on osteoblast cell adhesion to polished titanium-aluminum-vanadium and polished or grit-blasted cobalt-chromium-molybdenum alloys. Osteoblast binding was tested in the presence and absence of the cell adhesion proteins fibronectin, laminin, fibrinogen, and vitronectin and was quantified by measurement of DNA content. Although adherence occurred in serum-free medium, maximal osteoblast binding required serum and was similar for titanium and cobalt alloys at 2 and 12 hours. With the grit-blasted cobalt alloy, cell binding was reduced 48% (p < 0.05) by 24 hours. Coating the alloys with diamond-like carbon did not alter osteoblast adhesion, whereas fibronectin pretreatment increased cell binding 2.6-fold (p < 0.05). In contrast, fibrinogen, vitronectin, and laminin did not enhance cell adhesion. These results support the hypothesis that cell adhesion proteins can modify cell binding to orthopaedic alloys. Although osteoblast binding was not affected by the presence of diamond-like carbon, this coating substance may influence other longer term processes, such as bone formation, and deserves further study.

  View details for Web of Science ID A1996WC77400004

  View details for PubMedID 8982128

• RT-PCR analysis of MMP-9 expression in human articular cartilage chondrocytes and synovial fluid cells BIOTECHNIC & HISTOCHEMISTRY Tsuchiya, K., Maloney, W. J., Vu, T., Hoffman, A. R., Schurman, D. J., Smith, R. L. 1996; 71 (4): 208-213

  Abstract

  This report presents a method for analyzing matrix metalloproteinase-9 (92 kD gelatinase) MMP-9 mRNA expression using reverse transcription polymerase chain reaction (RT-PCR). With this method, chondrocytes isolated from small samples of osteoarthritic cartilage showed significantly elevated signal for MMP-9 mRNA compared to normal cartilage. In addition, cells of synovial fluid samples aspirated from osteoarthritic joints also exhibited MMP-9 expression using this technique. RT-PCR proved to be a sensitive method for assessing MMP-9 regulation in osteoarthritic and normal cartilage, and may provide a useful index of arthritic cartilage and synovial fluid cell metabolism when limited tissue is available.

  View details for Web of Science ID A1996VE64300007

  View details for PubMedID 8874859

• In vitro activation of human fibroblasts by retrieved titanium alloy wear debris JOURNAL OF ORTHOPAEDIC RESEARCH Manlapaz, M., Maloney, W. J., Smith, R. L. 1996; 14 (3): 465-472

  Abstract

  Titanium-aluminum-vanadium wear particles isolated from the soft-issue membrane of a failed total hip arthroplasty were added to human fibroblasts in cell culture. The cellular response to particle challenge was determined by assaying for levels of interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, prostaglandin E2, basic fibroblast growth factor, platelet-derived growth factor-AB, and transforming growth factor-beta. Collagenase and gelatinase activities were analyzed by zymography and [3H]collagen degradation. Cell viability was assessed by measuring the uptake of [3H]thymidine. Over the range of particle concentrations tested, cell viability, as demonstrated by [3H]thymidine uptake, remained unaffected. Fibroblasts exhibited a dose-dependent release of interleukin-6 in response to exposure to titanium-aluminum-vanadium particles. At 6 and 48 hours, the highest concentration of titanium alloy particles (0.189% [vol/vol]) resulted in 7-fold and 16-fold increases in interleukin-6 release, respectively, when compared with negative controls. Neither interleukin-1 beta nor tumor necrosis factor-alpha was detected in the culture medium at any particle concentration tested for both dermal and foreskin fibroblasts. The pattern of prostaglandin E2 release by fibroblasts mirrored the pattern of interleukin-6 release. Fibroblasts exposed to the highest concentration of titanium alloy particles showed an increase in collagenase activity, starting at 12 hours. When medium samples were treated with amino phenylmercuric acetate to activate latent enzymes, a statistically significant increase in collagenase activity was observed as early as 6 hours (p < 0.001). Substrate gel analysis of medium from fibroblasts stimulated by high particle concentrations also showed an increase in gelatinolytic activity when compared with unstimulated controls. Analysis of medium samples for growth factors showed an increase in basic fibroblast growth factor at low particle concentrations, beginning at 12 hours. Levels of platelet-derived growth factor-AB and transforming growth factor-beta were not detectable in the controls or at any particle concentration tested. The results of this study showed that fibroblasts exposed to titanium alloy wear particles become activated and release proinflammatory mediators that influence bone metabolism. These data support the hypothesis that direct activation of fibroblasts by particulate wear may play a role in particle-mediated osteolysis. Fibroblast activation coupled with the biologic response of macrophages to wear debris in the loosening membrane may have a synergistic effect on pathologic bone resorption.

  View details for Web of Science ID A1996UT65500016

  View details for PubMedID 8676260

• Chondrocytes from osteoarthritic cartilage have increased expression of insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) and -5, but not IGF-II or IGFBP-4 JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM Olney, R. C., Tsuchiya, K., Wilson, D. M., Mohtai, M., Maloney, W. J., Schurman, D. J., Smith, R. L. 1996; 81 (3): 1096-1103

  Abstract

  Osteoarthritis is a disease in which articular cartilage metabolism is altered, leading to cartilage destruction. As insulin-like growth factor-I (IGF-I) is the major anabolic mediator for articular cartilage, and the IGF-binding proteins (IGFBPs) are an integral part of the IGF axis, they may play a role in the pathophysiology of osteoarthritis. Chondrocytes isolated from fibrillated and normal appearing areas of osteoarthritic human cartilage and from normal cartilage were studied for IGF and IGFBP expression. IGF and IGFBP messenger ribonucleic acids were analyzed by a RT-quantitative PCR technique and Northern blotting. In osteoarthritic chondrocytes, IGF-I message was increased 3.5-fold, IGFBP-3 was increased 24-fold, and IGFBP-5 was increased 16-fold over normal chondrocytes. Chondrocytes from normal appearing areas of cartilage from osteoarthritic joints had intermediate levels. Message levels for beta-actin, IGF-II, and IGFBP-4 were unchanged between the cartilage types. IGF and IGFBP production were analyzed by Western ligand blots and RIAs of conditioned medium from cartilage cultured in serum-free conditions. IGF-I was undetectable in conditioned medium from normal cartilage and increased in that from osteoarthritic cartilage. Osteoarthritic cartilage samples produced IGFBP-2, -3, and -4; glycosylated IGFBP-4; and IGFBP-5. IGFBP-2, -3, and -5 production was increased in osteoarthritic cartilage. Proteases with activity against IGFBP-3 and -5 were also produced by osteoarthritic cartilage. The observation that IGFBP-3 and -5 expression and production are elevated in osteoarthritic cartilage suggests that they may be acting as a competitor for IGF-I in osteoarthritic cartilage, thus reducing the anabolic stimulation of this tissue and contributing to the net loss of cartilage in this disease.

  View details for PubMedID 8772582

• Increasing incidence of femoral osteolysis in association with uncemented Harris-Galante total hip arthroplasty - A follow-up report JOURNAL OF ARTHROPLASTY Maloney, W. J., Woolson, S. T. 1996; 11 (2): 130-134

  Abstract

  Sixty-nine consecutive uncemented total hip arthroplasties were performed in 59 patients using the Harris-Galante prosthesis (Zimmer, Warsaw, IN). The patients were reviewed an average of 44 and 71 months after surgery. Patients in whom femoral osteolysis was identified at the time of the first review were again evaluated at the second review to determine if the size of the osteolytic lesion had increased over time. At the initial review an average of 44 months postsurgery, the overall incidence of femoral osteolysis was 22%. At the second review, the incidence of femoral osteolysis had increased from 22 to 52%. Two thirds of the lytic lesions diagnosed at the time of the first review had increased in size. This study demonstrated that the incidence of femoral osteolysis in cementless hip arthroplasties increases with time and that the majority of existing lesions enlarge over time. Once lesions are identified, more frequent follow-up evaluations are recommended. Revision surgery may be required for progressive femoral osteolysis, despite the absence of significant clinical symptoms.

  View details for Web of Science ID A1996TX39900005

  View details for PubMedID 8648304

• Periprosthetic osteolysis in total hip arthroplasty: The role of particulate wear debris 1995 Instructional Course Lectures, at the Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons Maloney, W. J., Smith, R. L. AMER ACAD ORTHOPAEDIC SURGEONS. 1996: 171–182

  View details for Web of Science ID A1996BH44V00020

  View details for PubMedID 8727736

• Human macrophage response to retrieved titanium alloy particles in vitro CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., James, R. E., Smith, R. L. 1996: 268-278

  Abstract

  Titanium alloy particles were isolated from membranes obtained at revision arthroplasty. Addition of these retrieved particles to human monocytes/macrophages in cell culture resulted in morphologic change and metabolic activation. Cells exposed to these particles actively phagocytized the metallic debris, resulting in an increase in cytoplasm and a polarization of ingested metal. The metabolic response of the macrophages included increased release of prostaglandin E2, interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha, and increased hexosaminidase activity. Increased release of interleukin-1 beta was maximal 6 to 12 hours after particle exposure. These data show that retrieved titanium alloy particles activate macrophages in vitro in an analogous fashion to that observed around failed arthroplasties.

  View details for Web of Science ID A1996TP57400032

  View details for PubMedID 8542704

• ISOLATION AND CHARACTERIZATION OF WEAR PARTICLES GENERATED IN PATIENTS WHO HAVE HAD FAILURE OF A HIP-ARTHROPLASTY WITHOUT CEMENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Smith, R. L., Schmalzried, T. P., Chiba, J., HUENE, D., Rubash, H. 1995; 77 (9): 1301-1310

  Abstract

  Wear particles from thirty-five membranes obtained during revision hip-replacement operations were studied after digestion of the soft tissue with papain. The particles were isolated and were characterized with use of light and scanning electron microscopic techniques, x-ray microanalysis, and an automated particle analyzer. The mean size of the polyethylene particles was 0.5 micrometer, and the metal particles were a mean of 0.7 micrometer, as determined with scanning electron microscopy. The automated particle analyzer revealed a mean particle diameter of 0.63 micrometer (more than 90 per cent of all particles were less than 0.95 micrometer) and a mean of 1.7 billion particles per gram of tissue, compared with only 143 million per gram of tissue for the control samples. X-ray microanalysis revealed metal debris in sixteen (46 per cent) of the thirty-five membranes after digestion. Thirteen (50 per cent) of the twenty-six membranes surrounding a titanium-alloy stem contained metal particles, compared with three of the nine membranes surrounding a chromium-cobalt stem. Metal debris was present in only one of the twelve membranes surrounding a titanium-alloy stem without a porous coating, compared with twelve of the fourteen membranes surrounding a titanium-alloy stem with a porous coating. This tenfold difference in prevalence was significant (p < 0.005). On the average, the total number of particles (expressed in millions per gram of tissue) associated with the bipolar acetabular components was twice that associated with the fixed acetabular components. In addition, there was a trend toward a larger mean size of the polyethylene particles in association with the bipolar cups. Our data indicate that particulate prosthetic debris in the tissues around failed femoral components that have been inserted without cement constitutes a class of particles that are predominantly less than one micrometer in size and are present in amounts of more than one billion particles per gram of tissue. Routine histological methods did not detect this class of wear debris and led to a gross underestimation of the amount of debris in these membranes.

  View details for Web of Science ID A1995RV56800002

  View details for PubMedID 7673277

• PERIPROSTHETIC OSTEOLYSIS IN TOTAL HIP-ARTHROPLASTY - THE ROLE OF PARTICULATE WEAR DEBRIS JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Smith, R. L. 1995; 77 (9): 1448-1461

  View details for Web of Science ID A1995RV56800022

• ETIOLOGY OF OSTEOLYSIS AROUND POROUS-COATED CEMENTLESS TOTAL HIP ARTHROPLASTIES CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Jasty, M., Bragdon, C., Jiranek, W., Chandler, H., Maloney, W., Harris, W. H. 1994: 111-126

  Abstract

  The prosthetic components and tissues retrieved from 12 hips with osteolysis in association with well-fixed cementless porous-coated total hip prostheses (5 Porous Coated Anatomic, 6 Harris-Galante Porous, and 1 Omniflex) were examined using a variety specific techniques including electron microscopy, standard histology, immunohistochemistry, and particle identification. The patients were young and active. Extensive osteolysis developed in all 12 femurs and 3 acetabula between 36 and 84 months after arthroplasty (mean, 63 months). All of the polyethylene liners were noted to be worn substantially (mean volumetric wear, 1140 +/- 810 mm3). The wear was unrelated to the head diameter in this small number of cases. In all 12 cases, the articulating surfaces were wear polished and contained numerous fine multidirectional scratches, suggesting 3-body abrasive wear mechanisms in addition to adhesive wear liberating very small (micron to submicron) wear particles. In 4 cases, surface delamination and flaking of polyethylene were also found, suggesting fatigue wear liberating larger wear particles. Nine of 10 cobalt alloy heads showed numerous fine scratches with sharp edges presumably from 3-body abrasive wear. Corrosion and fretting at the femoral head-neck junction in 5 cases, burnishing of the femoral stem against bone in 4 cases, and metal staining of tissues opposite the porous coatings in 7 cases provided evidence for the liberation of fine metal particles from outside the articulation. Histologic and immunohistochemical studies of tissue in the regions of osteolysis in all cases showed numerous focal aggregates of KP1 antibody positive activated macrophages containing large amounts of submicron intracellular particles of polyethylene (presumably related to the 3-body abrasive wear polishing) and giant cells within a fibrous stroma. In 5 cases, some of the macrophages also contained submicron metal particles but smaller in numbers. T lymphocytes, plasma cells, and mast cells that might indicate hypersensitivity were found in 4 of the 12 cases (33%), and none of the cases had B lymphocytes. These data suggest that abrasive wear at the articulation leads to the liberation of abundant fine particulate wear debris of polyethylene into the tissues around cementless prostheses. Small amounts of particulate metal debris are also liberated from corrosion and fretting of the metal components and can contribute to accelerated 3-body abrasive wear at the articulation.(ABSTRACT TRUNCATED AT 400 WORDS)

  View details for Web of Science ID A1994PQ77700018

  View details for PubMedID 7955673

• EFFECTS OF METALLIC DEBRIS ON ADULT BOVINE ARTICULAR CHONDROCYTE METABOLISM IN-VITRO JOURNAL OF APPLIED BIOMATERIALS Maloney, W. J., CASTRO, F., Schurman, D. J., Smith, R. L. 1994; 5 (2): 109-115

  View details for Web of Science ID A1994NL92200002

• COMPENSATING FOR CHANGES IN MUSCLE LENGTH IN TOTAL HIP-ARTHROPLASTY - EFFECTS ON THE MOMENT GENERATING CAPACITY OF THE MUSCLES CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Vasavada, A. N., Delp, S. L., Maloney, W. J., Schurman, D. J., Zajac, F. E. 1994: 121-133

  Abstract

  Alterations in the location of the hip center may change the lengths and moment arms of the muscles, and thereby affect their capacity to generate force and moment about the hip. This study demonstrates some of the differences between compensating and not compensating for changes in muscle length that arise from displacement of the hip center. A computer model was developed to estimate the maximum isometric moment generating capacity of the hip muscles under two conditions. In the compensated condition, the hip center was displaced, but the muscles were restored to their original lengths and orientations by altering proximal femoral geometry. In the uncompensated condition, femoral geometry remained constant; thus, muscle lengths and orientations changed with displacement of the hip center. The computer simulations showed large differences between the two conditions. For example, a 2-cm superior displacement of the hip center decreased the moment generating capacity of the hip abductors 18% with compensation and 49% without compensation. Similarly, a 1-cm medial displacement of the hip center increased the moment generating capacity of the abductors 17% with compensation, but decreased it 4% without compensation. In contrast, a 1-cm inferior displacement decreased the moment generating capacity of flexors 6% with compensation, but increased it 12% without compensation. The results presented here demonstrate that compensating for changes in muscle length can be important in terms of preserving the moment generating capacity of the muscles when the hip center is displaced superiorly and medially, but not when the hip center is displaced in the inferior direction.

  View details for Web of Science ID A1994NL07400020

  View details for PubMedID 8168289

• A quantitative in vitro assessment of fit and screw fixation on the stability of a cementless hemispherical acetabular component. journal of arthroplasty Kwong, L. M., O'Connor, D. O., SEDLACEK, R. C., Krushell, R. J., Maloney, W. J., Harris, W. H. 1994; 9 (2): 163-170

  Abstract

  This investigation quantifies in vitro the effect of component fit, as well as the effect of adjuvant screw fixation, on the initial stability of cementless hemispherical titanium acetabular total hip arthroplasty components and assesses apposition of the acetabular components to bone. Six, fresh human hemipelvi (3 matched pairs) were harvested at autopsy. Titanium alloy acetabular components with a porous surface of commercially pure titanium fiber mesh (Harris Galante Porous acetabular components, Zimmer, Warsaw, IN) were used for implantation. Initially, each acetabulum was underreamed to achieve a 2 mm press-fit with the acetabular component. Pressure-sensitive film had been placed along the dome and medial wall at the bone-implant interface to assess the completeness of seating. After the implant was impacted into the acetabular cavity, relative motion between the implant and bone was measured during simulated single leg stance. Adjuvant fixation of the implant was then obtained with the insertion of four 6.5 mm cancellous screws. High-contrast roentgenograms of the specimens in multiple views were obtained after initial cup insertion and again after screw insertion. The stability of each implant under load was measured with four, three, two, one, and no screws in place. Further reaming of the bone was done to create a 1 mm press-fit. The sequence was then repeated. Further reaming was done to create an exact-fit and the sequence was repeated again. Under these conditions, 1 mm press-fit with or without screws provided the optimum combination of fit stability.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 8014647

• SEVERE OSTEOLYSIS OF THE PELVIS IN ASSOCIATION WITH ACETABULAR REPLACEMENT WITHOUT CEMENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Peters, P., Engh, C. A., Chandler, H. 1993; 75A (11): 1627-1635

  View details for Web of Science ID A1993MK98500007

• Severe osteolysis of the pelvic in association with acetabular replacement without cement. journal of bone and joint surgery. American volume Maloney, W. J., Peters, P., Engh, C. A., Chandler, H. 1993; 75 (11): 1627-1635

  Abstract

  We reviewed the cases of fourteen patients (fifteen lesions) who had osteolysis following the replacement of the acetabulum without cement. Nine women and five men, seventeen to sixty-seven years old, were involved in the study. One woman had bilateral pelvic osteolysis. Eight of the fifteen index acetabular reconstructions were done with a titanium-alloy implant and seven, with a chromium-cobalt-alloy implant. Eleven of the fifteen acetabular components had holes in the metal shell that may have acted as a conduit through which wear debris could gain access to the implant-bone interface, but only two of the acetabular components had been fixed with screws. In these two acetabular components, all available screw holes were not filled. The polyethylene liner was eight millimeters thick or less in twelve of the fifteen acetabular components; all of the liners were ten millimeters thick or less. The diameter of the head of eleven of the fifteen femoral components was thirty-two millimeters. Fourteen of the fifteen femoral components were placed without cement, and all but one was radiographically stable. The duration from the index operation to the appearance of pelvic osteolysis ranged from fifty-three to eighty-four months (mean, sixty-five months). At the time of the diagnosis, the patients were functioning well clinically, and all but three had a Harris hip score of 90 points or better, despite extensive destruction of bone in some instances. Since these patients were functioning well, the pelvic osteolysis was diagnosed radiographically at a regular follow-up examination. Only one patient had evidence of migration of the acetabular component on serial radiographs.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 8245055

• Fibroblast response to metallic debris in vitro. Enzyme induction cell proliferation, and toxicity. journal of bone and joint surgery. American volume Maloney, W. J., Smith, R. L., CASTRO, F., Schurman, D. J. 1993; 75 (6): 835-844

  Abstract

  Bovine synovial fibroblasts in primary monolayer culture were exposed to particulate metallic debris. The effects of the metallic particles on the synthesis and secretion of proteolytic enzymes and on cell proliferation and viability were examined. Uniform suspensions of titanium, titanium-aluminum, cobalt, and chromium particles, ranging in size from approximately 0.1 to ten micrometers (average, one to three micrometers), were prepared; the particle concentrations (the volume of particles divided by the total volume of the suspension) ranged from 0.0005 to 5 per cent. Aliquots of the particle suspensions were added to the synovial fibroblast cultures. The final particle concentrations in the media ranged from 0.0000083 to 0.83 per cent. After seventy-two hours of exposure, each medium was harvested and was assayed for proteolytic and collagenolytic activity and for hexosaminidase levels. Neutral metalloproteases, quantified by collagenolytic and caseinolytic (proteolytic) activity, represent enzymes, secreted by cells, that are capable of degrading extracellular matrix. Hexosaminidase is a marker for lysosomal enzyme activity that can include more than thirty enzymes, such as proteases, lipases, nucleases, and phosphatases. Cell proliferation was quantified by uptake of 3H-thymidine. Cell morphology was examined by scanning electron microscopy. Titanium, titanium-aluminum, and chromium significantly stimulated 3H-thymidine uptake at low particle concentrations (p < 0.01, p < 0.002, and p < 0.002, respectively). Exposure to cobalt, even at the lowest particle concentration, resulted in a significant decrease in thymidine uptake (p = 0.027). At the highest particle concentrations, all particles were toxic, as evidenced by the absence of thymidine uptake. At high particle concentrations, all of the metals caused a decrease in caseinolytic (proteolytic) and collagenolytic activity in the culture media. Titanium elevated the lysosomal enzyme marker, hexosaminidase, except at high concentrations. Chromium and titanium-aluminum had no significant effect on hexosaminidase at any particle concentration, while cobalt decreased all enzyme markers at mid-particle to high-particle concentrations. Scanning electron microscopy demonstrated that the morphological response of fibroblasts to titanium included membrane-ruffling and extension of filopodia, typical of active fibroblasts. In contrast, exposure to cobalt at the same concentration resulted in cell crenation, indicative of cell death.

  View details for PubMedID 8314824

• FIBROBLAST RESPONSE TO METALLIC DEBRIS IN-VITRO - ENZYME-INDUCTION, CELL-PROLIFERATION, AND TOXICITY JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Smith, R. L., CASTRO, F., Schurman, D. J. 1993; 75A (6): 835-844

  Abstract

  Bovine synovial fibroblasts in primary monolayer culture were exposed to particulate metallic debris. The effects of the metallic particles on the synthesis and secretion of proteolytic enzymes and on cell proliferation and viability were examined. Uniform suspensions of titanium, titanium-aluminum, cobalt, and chromium particles, ranging in size from approximately 0.1 to ten micrometers (average, one to three micrometers), were prepared; the particle concentrations (the volume of particles divided by the total volume of the suspension) ranged from 0.0005 to 5 per cent. Aliquots of the particle suspensions were added to the synovial fibroblast cultures. The final particle concentrations in the media ranged from 0.0000083 to 0.83 per cent. After seventy-two hours of exposure, each medium was harvested and was assayed for proteolytic and collagenolytic activity and for hexosaminidase levels. Neutral metalloproteases, quantified by collagenolytic and caseinolytic (proteolytic) activity, represent enzymes, secreted by cells, that are capable of degrading extracellular matrix. Hexosaminidase is a marker for lysosomal enzyme activity that can include more than thirty enzymes, such as proteases, lipases, nucleases, and phosphatases. Cell proliferation was quantified by uptake of 3H-thymidine. Cell morphology was examined by scanning electron microscopy. Titanium, titanium-aluminum, and chromium significantly stimulated 3H-thymidine uptake at low particle concentrations (p < 0.01, p < 0.002, and p < 0.002, respectively). Exposure to cobalt, even at the lowest particle concentration, resulted in a significant decrease in thymidine uptake (p = 0.027). At the highest particle concentrations, all particles were toxic, as evidenced by the absence of thymidine uptake. At high particle concentrations, all of the metals caused a decrease in caseinolytic (proteolytic) and collagenolytic activity in the culture media. Titanium elevated the lysosomal enzyme marker, hexosaminidase, except at high concentrations. Chromium and titanium-aluminum had no significant effect on hexosaminidase at any particle concentration, while cobalt decreased all enzyme markers at mid-particle to high-particle concentrations. Scanning electron microscopy demonstrated that the morphological response of fibroblasts to titanium included membrane-ruffling and extension of filopodia, typical of active fibroblasts. In contrast, exposure to cobalt at the same concentration resulted in cell crenation, indicative of cell death.

  View details for Web of Science ID A1993LK82800005

• EFFECTS OF HIP CENTER LOCATION ON THE MOMENT-GENERATING CAPACITY OF THE MUSCLES JOURNAL OF BIOMECHANICS Delp, S. L., Maloney, W. 1993; 26 (4-5): 485-499

  Abstract

  We have developed a three-dimensional biomechanical model of the human lower extremity to study how the location of the hip center affects the moment-generating capacity of four muscle groups: the hip abductors, adductors, flexors, and extensors. The model computes the maximum isometric force and the resulting joint moments that each of 25 muscle-tendon complexes develops at any body position. Abduction, adduction, flexion, and extension moments calculated with the model correspond closely with isometric joint moments measured during maximum voluntary contractions. We used the model to determine (1) the hip center locations that maximize and minimize the moment-generating capacity of each muscle group and (2) the effects of superior-inferior, anterior-posterior, and medial-lateral displacement of the hip center on the moment arms, maximum isometric muscle forces, and maximum isometric moments generated by each muscle group. We found that superior-inferior displacement of the hip center has the greatest effect on the force- and moment-generating capacity of the muscles. A 2 cm superior displacement decreases abduction force (44%), moment arm (12%), and moment (49%), while a 2 cm inferior displacement increases abduction force (20%), moment arm (7%) and moment (26%). Similarly, a 2 cm superior displacement decreases flexion force (27%), moment arm (6%), and moment (22%), while inferior displacement increases all three variables. Anterior-posterior displacement alters the moment-generating capacity of the flexors and extensors considerably, primarily due to moment arm changes. Medial-lateral displacement has a large effect on the moment-generating capacity of the adductors only. A 2 cm medial displacement decreases adduction moment arm (20%), force (26%) and moment (40%). These results demonstrate that the force- and moment-generating capacities of the muscles are sensitive to the location of the hip center.

  View details for Web of Science ID A1993KX57600011

  View details for PubMedID 8478351

• AUTOPSY STUDIES OF THE BONE-CEMENT INTERFACE IN WELL-FIXED CEMENTED TOTAL HIP ARTHROPLASTIES SPECIAL MEETING OF THE HIP IMPLANT RETRIEVAL COMMITTEE OF THE HIP SOC : IMPLANT RETRIEVAL ANALYSIS Schmalzried, T. P., Maloney, W. J., Jasty, M., Kwong, L. M., Harris, W. H. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 1993: 179–88

  Abstract

  Although knowledge of the clinical status of the implant is important, only instrumented mechanical testing of retrieved specimens provides quantitative assessment of implant fixation. This measurement allows placement of the implant along a continuum of loosening and is the foundation for the interpretation of subsequent findings. Analysis of implants that have been proven to be well fixed by instrumented testing reveals significant differences in the initial events in the loosening of femoral and acetabular components. Although radiolucencies were observed around all of these well-fixed femoral and acetabular components, the histology (and therefore the etiology) of the radiolucency is different and variable on the two sides of the articulation. The majority of femoral radiolucencies appear to be due to age and stress-related remodeling while particulate-induced bone resorption plays an important role in acetabular radiolucencies. A finding common to both sides of the articulation in these stable components, however, was intimate contact of bone with cement without any interposed soft tissue even after 17.5 years of service. Primary incompatibility and/or failure of the cement was not identified as a factor in initiating either femoral or acetabular component loosening. These studies document the long-term compatibility of bone with cement in bulk form. Improvements in cemented femoral component fixation should focus on stem design and cementing technique. Long-term acetabular component fixation can be improved by reduction or elimination of polyethylene wear and optimization of the bone-implant interface.

  View details for Web of Science ID A1993KW98700011

  View details for PubMedID 8478634

• THE CEMENT INTERFACE - RETRIEVAL STUDIES 7TH ANNUAL BRISTOL-MYERS SQUIBB / ZIMMER ORTHOPAEDIC RESEARCH SYMP : BIOLOGICAL, MATERIAL, AND MECHANICAL CONSIDERATIONS OF JOINT REPLACEMENT Maloney, W. J., Schmalzried, T. P., Jasty, M., Kwong, L. M., Harris, W. H. RAVEN PRESS. 1993: 51–69

  View details for Web of Science ID A1993BY98W00006

• SEGMENTAL CEMENT EXTRACTION AT REVISION TOTAL HIP-ARTHROPLASTY CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Schurman, D. J., Maloney, W. J. 1992: 158-163

  Abstract

  Cement removal in revision total hip arthroplasty can be technically challenging. Traditional methods involve using a combination of chisels, power burrs, and drills, as well as windowing the femoral cortex to gain access to cement distally. These methods can be associated with femoral fracture or uncontrolled cortical perforation and bone loss. A new technique had been developed that permits segmental extraction of bone cement from the femoral canal. Fresh cement is introduced into the old cement mantle and a threaded rod is placed into the wet cement and held in place while the cement hardens. The thread-forming rod is then removed leaving a threaded channel in the cement. Extraction rods are then screwed 1.5 to 2.5 cm into the threaded channel. A slap hammer, which attaches to the opposite end of the extraction rod, is used to remove 1.5- to 2.5-cm segments of cement. Fifteen cases involving revision of cemented femoral components were analyzed using this system. Complete cement removal was achieved in 12 cases with much less damage to the femur when compared with conventional methods. In two cases, there was retained cement along the medial wall of the femur and, in one case, the plug could not be extracted using this system. There were no fractures or cortical perforations in this series.

  View details for Web of Science ID A1992KB63200021

  View details for PubMedID 1446433

• Bone ingrowth into a low-modulus composite plastic porous-coated canine femoral component. journal of arthroplasty Jasty, M., Bragdon, C. R., Maloney, W. J., Mulroy, R., HAIRE, T., Crowninshield, R. D., Harris, W. H. 1992; 7 (3): 253-259

  Abstract

  Bone ingrowth into low-modulus canine femoral components made of composite plastics and porous coated with titanium fiber mesh was evaluated and compared to that found in femoral components of the same design made of titanium alloy and porous coated with titanium fiber mesh. Both types of components demonstrated extensive bone ingrowth into the porous coatings at 6 weeks and there were no differences in the histologic appearance of the tissue ingrowth in the two groups. The amount of bone that grew into the porous surface, the areal density of bone within the available pore space, and the extent of the prosthesis periphery with bone ingrowth were not significantly varied in the two different components. The results of this study show that adequate fixation of low-modulus composite femoral components porous coated with titanium fiber mesh by bone ingrowth can occur and that further investigation of these materials for femoral components may be warranted.

  View details for PubMedID 1402939

• BEAD LOOSENING FROM A POROUS-COATED ACETABULAR COMPONENT - A FOLLOW-UP NOTE CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Davey, J. R., Harris, W. H. 1992: 112-114

  Abstract

  Beaded porous-coated implants are commonly used in total joint arthroplasty. In this study, the authors extended the follow-up period for the Davey and Harris study of bead loosening in beaded cementless acetabular components. When 56 primary total hip arthroplasties were first reviewed, at an average of 2.5 years after surgery, the incidence of bead loosening was 8.9%. Reevaluation at a mean of 4.5 years after surgery revealed that the incidence of loosening had increased to 19.6%. Bead loosening was associated with acetabular migration in one component and a broken screw in a second. In the absence of loose beads, there were no broken fixation screws or socket migration. Radiolucencies at the bone-implant interface were seen in association with loose beads in only one case. Although long-term implications of bead loosening are not clear, bead migration may increase the possibility of macrophage response to metallic debris.

  View details for Web of Science ID A1992JG97700019

  View details for PubMedID 1499196

• PROPHYLAXIS FOR HETEROTOPIC BONE-FORMATION AFTER TOTAL HIP-ARTHROPLASTY USING LOW-DOSE RADIATION IN HIGH-RISK PATIENTS CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Jasty, M., Willett, C., MULROY, R. D., Harris, W. H. 1992: 230-234

  Abstract

  Fifteen consecutive total hip arthroplasties (THAs) in 14 patients considered at risk for developing significant heterotopic ossification (HO) were treated postoperatively with 7.5 Gy of external beam radiation in three fractions. Eight hips in eight of the patients (Group I) had developed previous Brooker Class III or IV HO after THA and were radiated after having excision of HO in conjunction with a revision THA. Three additional hips in three patients (Group II) were radiated after primary THA, because they developed significant HO on the contralateral hip after a previous THA. The remaining four hips in three patients (Group III) were radiated after primary THA because they had bilateral hypertrophic arthritis. Precision shielding was employed to minimize the volume of tissue in the radiation field and to protect the bone-implant interface around porous-coated components and the trochanteric osteotomy sites. Of the eight hips in which Class III or IV bone was excised during revision THA (Group I), no new bone formed in five hips and in the other three hips, only Class I bone formed. No heterotopic bone formed in the remaining seven hips of Groups II and III. All six trochanteric osteotomies healed. There were no wound healing problems. There were no significant radiolucencies around any of the components and there was no radiographic evidence of implant instability. This regimen using 7.5 Gy over three fractions minimizes the radiobiologic impact, whereas the use of precision shielding minimizes the total volume of tissue treated. This regimen is an effective means of preventing significant HO after THA in high-risk patients while minimizing radiation exposure.

  View details for Web of Science ID A1992JC24600030

  View details for PubMedID 1611750

• THE EFFECTS OF IMPLANT DESIGN ON RANGE OF MOTION AFTER TOTAL KNEE ARTHROPLASTY - TOTAL CONDYLAR VERSUS POSTERIOR STABILIZED TOTAL CONDYLAR DESIGNS CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Schurman, D. J. 1992: 147-152

  Abstract

  Range of motion (ROM) after total knee arthroplasty (TKA) is an important variable in determining clinical outcome. Recent design modifications have been aimed at improving final motion. The posterior stabilized total knee prosthesis was introduced as a modification of the total condylar design, changing the center of curvature of the femoral component to allow greater ROM. In this study, all primary TKAs performed at the authors' institution from July 1982 until December 1986 were reviewed to determine the effect of this design modification on outcome. A total condylar (TC) group comprised 51 arthroplasties and was compared to 53 arthroplasties in a posterior stabilized (PSTC) group. the postoperative protocol was identical in both groups. The mean postoperative flexion was 11 better in the PSTC group; however, the mean preoperative flexion had initially been 10 degrees better in the PSTC group. The maximum flexion achieved by any patient in both groups was similar, but the TC group actually gained slightly more arc of motion. The better motion in the PSTC group may be secondary to better motion preoperatively and not implant design in this series. The more limited the preoperative ROM, the greater the quadriceps stiffness is likely to be, which is an important determinant of postoperative flexion. Review of the literature supports present observations that a group with less mean preoperative motion paradoxically gains a slightly greater increment of flexion. Differences in flexion after TKA are difficult to attribute to design in either the current study or by a review of the literature. This is because determinants of flexion after TKA are multifactorial and outcome data limited, notwithstanding the similarities among modern prostheses.

  View details for Web of Science ID A1992HR56200024

  View details for PubMedID 1563146

• The progression of femoral cortical osteolysis in association with total hip arthroplasty without cement. journal of bone and joint surgery. American volume Tanzer, M., Maloney, W. J., Jasty, M., Harris, W. H. 1992; 74 (3): 404-410

  Abstract

  Twenty hips in twenty patients had development of femoral endosteal cortical erosion after a cementless total hip replacement with the Harris-Galante porous-coated implant. Serial anteroposterior and lateral radiographs of all of the affected femora were reviewed to determine the interval between the operation and the first recognition of the osteolytic lesion or lesions, as well as to evaluate the radiographic appearance and progression of the lesions. The twenty affected hips were followed for an average of fifty-three months (range, twenty to seventy-seven months) after the operation. Osteolysis was first noted radiographically at twelve to sixty-six months (mean, thirty-nine months) postoperatively; in most patients, it occurred around the distal portion of the prosthetic stem. Twelve (60 per cent) of the femoral components were shown to be loose, as proved either radiographically or operatively. Three of these components had been judged radiographically to be stable when the endosteal erosion had first been identified, but they had subsequently migrated. The remaining eight hips had no evidence of loosening. The osteolysis was more severe in the femora in which the component was loose than in those in which it was stable. Of the fourteen patients who were followed, twelve (86 per cent) had an increase in the size of the osteolytic lesions with time, and only one patient had some radiographic evidence of healing.

  View details for PubMedID 1548268

• THE PROGRESSION OF FEMORAL CORTICAL OSTEOLYSIS IN ASSOCIATION WITH TOTAL HIP-ARTHROPLASTY WITHOUT CEMENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Tanzer, M., Maloney, W. J., Jasty, M., Harris, W. H. 1992; 74A (3): 404-410

  View details for Web of Science ID A1992HM90500012

• In vitro study of initial stability of a conical collared femoral component. journal of arthroplasty Fischer, K. J., Carter, D. R., Maloney, W. J. 1992; 7: 389-395

  Abstract

  This in vitro experimental study compared the initial stability of an uncemented conical collared femoral component to that of the same component with the collar removed. The two configurations examined simulated joint resultant forces encountered in single leg stance and stair climbing. For the simulated single leg stance loads, the data do not allow any inferences about relative component stability. With the exception of one collarless control, all micromotion for single leg stance loading was under 150 microns, measured approximately 1.5 cm below the resection line. For scaled stair-climbing loads, however, the conical collared component group was significantly more stable than the collarless control group in transverse (primarily rotational) micromotion. The overall average measured transverse motion for the collarless control group was more than 3.7 times greater than that of the conical collar group at scaled stair-climbing loads. The two conical collared components loaded to full peak stair-climbing load (2,100 N) exhibited micromotion under 160 microns. The results suggest that the conical collar may improve stability of an uncemented prosthesis under loads that include an out-of-plane (rotational) component.

  View details for PubMedID 1431921

• ENDOSTEAL OSTEOLYSIS AROUND WELL-FIXED POROUS-COATED CEMENTLESS FEMORAL COMPONENTS SYMP ON BIOCOMPATIBILITY OF PARTICULATE IMPLANT MATERIALS Jasty, M., Maloney, W. J., Harris, W. H., Galante, J. O., Callaghan, J. J. AMER SOC TESTING AND MATERIALS. 1992: 61–67

  View details for Web of Science ID A1992BV37B00005

• Cementless total hip arthroplasty using a porous-coated prosthesis for bone ingrowth fixation. 3 1/2-year follow-up. journal of arthroplasty Woolson, S. T., Maloney, W. J. 1992; 7: 381-388

  Abstract

  The clinical and radiologic results of a consecutive series of 59 patients (69 hips) who had primary total hip arthroplasty using cementless prostheses was studied. Harris-Galante acetabular and femoral prostheses, which have a porous fiber-metal mesh coating intended to encourage bone ingrowth fixation, were used in all cases. Two femoral components were revised during the follow-up period, one for aseptic loosening and the other for late septic loosening. In the remaining 67 hips, the average Harris hip score rose from a preoperative 52 to 94 at the last follow-up examination (average follow-up period, 44 months). Eighty-eight percent of these hips had an excellent result (Harris hip score of 90 or more). Radiologic analysis demonstrated that all the acetabular components were stable. Eighty-three percent of the femoral components appeared to have stable bone ingrowth fixation, five components (7%) had stable fibrous ingrowth, and seven (10%) were unstable. Parallel radiodense lines were seen around the smooth portion of the stem in 93% of hips, but this finding appeared to have no clinical importance. Significant stress shielding of the proximal femur was seen in 16% of hips. Endosteal lysis of the distal femur occurred in 22% of hips, including large lesions in two patients who will require future revision surgery because of femoral diaphysis weakening. Femoral lysis was not associated with hip or thigh pain and was most common in young, male patients who had high activity levels.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 1431920

• THE HISTOLOGY OF THE RADIOLUCENT LINE JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Kwong, L. M., Jasty, M., MULROY, R. D., Maloney, W. J., Bragdon, C., Harris, W. H. 1992; 74 (1): 67-73

  Abstract

  The radiographic and histological features of radiolucent areas at the cement-bone interface were correlated in 15 specimens retrieved at post-mortem from patients who had undergone cemented total hip arthroplasty, two weeks to 15 years prior to death. All but one of the components were securely fixed, as demonstrated by direct measurements of micromotion. Extensive radiolucencies were present in all but one case. In 11 of the 14 specimens with radiolucencies, histological examination showed that the radiolucent areas represented regions of osteoporosis and bone remodelling. The remodelling changes were characterised by osteoporosis, cancellisation and thinning of the endosteal cortex, and osteopenia of the trabecular bone. In two specimens the appearance of radiolucency was found to be due to fibrous tissue at the cement-bone interface and in one specimen there was a mixed picture of osteolysis and fibrosis. The study demonstrates that radiolucent lines can occur with well-fixed components and that they may commonly represent osteoporosis rather than the presence of a fibrous membrane at the cement-bone interface.

  View details for Web of Science ID A1992HA16800017

  View details for PubMedID 1732269

• Ingrowth of bone in failed fixation of porous-coated femoral components. journal of bone and joint surgery. American volume Jasty, M., Bragdon, C. R., Maloney, W. J., HAIRE, T., Harris, W. H. 1991; 73 (9): 1331-1337

  Abstract

  In five straight-stemmed, proximally porous-coated femoral components that were retrieved at revision arthroplasty from patients who had radiographic and clinical evidence of loosening, there was growth of bone into the porous coating. The components had been inserted during a primary arthroplasty in one woman and four men. The patients ranged in age from thirty-seven to sixty-seven years. Three patients were heavy, and all five were active. All patients had had an excellent early result from the initial arthroplasty; at the one-year follow-up, the mean Harris hip score had been 91 points. Pain in the hip developed in all of the patients, between one and three years after the index procedure. Initial radiographs had revealed excellent position and fixation of the prosthetic components, but the components then subsided between one and three and one-half years after the index procedure. All of the femoral components were found to be grossly loose at the revision operation. Nevertheless, all of the prosthetic components demonstrated growth of bone into 4 to 44 per cent (mean, 24 per cent) of the pore spaces available for ingrowth. Woven bone and fracture callus were found in the curettings from the proximal part of the femur. The findings in these five patients suggest that late failure of uncemented porous-surfaced femoral components can occur despite the presence of extensive ingrowth of bone. These failures may be the result of fatigue fractures of the trabeculae of the osseous ingrowth into the porous surfaces. Caution is warranted in the liberal use of these prosthetic components in heavy, active patients.

  View details for PubMedID 1918115

• INGROWTH OF BONE IN FAILED FIXATION OF POROUS-COATED FEMORAL COMPONENTS JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Jasty, M., Bragdon, C. R., Maloney, W. J., HAIRE, T., Harris, W. H. 1991; 73A (9): 1331-1337

  View details for Web of Science ID A1991GM83300007

• THE INITIATION OF FAILURE IN CEMENTED FEMORAL COMPONENTS OF HIP ARTHROPLASTIES JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Jasty, M., Maloney, W. J., Bragdon, C. R., OCONNOR, D. O., HAIRE, T., Harris, W. H. 1991; 73 (4): 551-558

  Abstract

  We studied 16 femora retrieved at post-mortem from symptomless patients who had a satisfactory cemented total hip arthroplasty from two weeks to 17 years earlier, with the aim of delineating the initial mechanisms involved in loosening. Only one specimen showed radiographic evidence of loosening; the other 15 were stable to mechanical testing at 17.0 Nm of torque. In all 16 specimens, the cement-bone interface was intact with little fibrous tissue formation. By contrast, separation at the cement-prosthesis interface and fractures in the cement mantle were frequent. The most common early feature was debonding of the cement from the metal, seen at the proximal and distal ends of the prosthesis. Specimens which had been in place for longer also showed circumferential fractures in the cement, near the cement-metal interface, and radial fractures extending from this interface into the cement and sometimes to the bony interface. The most extensive cement fractures appeared to have started at or near sharp corners in the metal, or where the cement mantle was thin or incomplete. Fractures were also related to voids in the cement. The time relationship in this series suggested that long-term failure of the fixation of cemented femoral components was primarily mechanical, starting with debonding at the interface between the cement and the prosthesis, and continuing as slowly developing fractures in the cement mantle.

  View details for Web of Science ID A1991FZ05900005

  View details for PubMedID 2071634

• INTRAOPERATIVE MEASUREMENT OF ROTATIONAL STABILITY OF FEMORAL COMPONENTS OF TOTAL HIP-ARTHROPLASTY CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Harris, W. H., MULROY, R. D., Maloney, W. J., Burke, D. W., Chandler, H. P., ZALENSKI, E. B. 1991: 119-126

  Abstract

  High out-of-plane forces acting on the hip joint can produce important rotational micromotion of the femoral component. This micromotion at the prosthesis interface may be detrimental to the stability of the implant. In cementless femoral implants this could prevent bone ingrowth, and in the cemented component this could cause generation of particulate debris, lysis, and loosening. The introduction of the torque wrench micrometer for assessment of intraoperative femoral component stability can quantify the initial stability of primary cementless femoral components and critically evaluate the stability (at either the initial or revision arthroplasty) of both cemented and cementless femoral components. It allows the surgeon to produce a known torque in the direction and magnitude of the out-of-plane forces that load the hip in vivo.

  View details for Web of Science ID A1991FK40100019

  View details for PubMedID 2019039

• INCIDENCE OF HETEROTOPIC OSSIFICATION AFTER TOTAL HIP-REPLACEMENT - EFFECT OF THE TYPE OF FIXATION OF THE FEMORAL COMPONENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Krushell, R. J., Jasty, M., Harris, W. H. 1991; 73A (2): 191-193

  View details for Web of Science ID A1991FA23400006

• Incidence of heterotopic ossification after total hip replacement: effect of the type of fixation of the femoral component. journal of bone and joint surgery. American volume Maloney, W. J., Krushell, R. J., Jasty, M., Harris, W. H. 1991; 73 (2): 191-193

  Abstract

  The incidence and severity of heterotopic ossification after sixty-five consecutive primary uncemented total hip replacements were compared with those after seventy consecutive primary hybrid total hip replacements (consisting of an uncemented acetabular component and a cemented femoral component). All patients had had the arthroplasty because of osteoarthrosis. The sex distribution, prevalence of bilateral disease of the hip, and frequency of previous operations were similar in both groups. All of the operations were performed by one surgeon who used the same operative approach. Preoperative, immediate postoperative, and six-month follow-up radiographs were reviewed for all patients. For 90 per cent of the hips, radiographs that were made after a minimum follow-up of one year were also reviewed. In the group of patients who had an uncemented femoral component, there was a statistically significant increase in the frequency of heterotopic bone and in its severity. Either none or only class-I ectopic bone developed in 74 per cent of the hips in the hybrid group, compared with 40 per cent of the hips in the uncemented group (p less than 0.005). In contrast, class-III or IV heterotopic ossification was evident in 13 per cent of the hips in the uncemented group (p less than 0.005). None of the patients in the hybrid group needed reoperation for excision of ectopic bone, but four (6 per cent) of the patients in the uncemented group needed such a reoperation because of severe limitation of motion.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 1899666

• SIMULTANEOUS CORRECTION OF PELVIC OBLIQUITY, FRONTAL PLANE, AND SAGITTAL PLANE DEFORMITIES IN NEUROMUSCULAR SCOLIOSIS USING A UNIT ROD WITH SEGMENTAL SUBLAMINAR WIRES - A PRELIMINARY-REPORT JOURNAL OF PEDIATRIC ORTHOPAEDICS Maloney, W. J., Rinsky, L. A., Gamble, J. G. 1990; 10 (6): 742-749

  Abstract

  Ten patients with neuromuscular scoliosis and pelvic obliquity had segmental spinal instrumentation using a unit Luque rod with sublaminar wires and fixation into the pelvis. Nine of the 10 patients also had anterior spinal fusion without instrumentation before the posterior procedure. Average preoperative pelvic obliquity was 42 degrees which was corrected to 6 degrees (82% correction). Average preoperative scoliosis was 92 degrees, which was corrected to 16 degrees (81% correction). Complications included a wound hematoma in one patient and a superficial wound dehiscence in another. There have been no pseudarthroses or hardware failures to date. Excellent correction of the pelvic obliquity and the spinal curve in neuromuscular scoliosis can be obtained with use of a unit rod and without use of anterior instrumentation.

  View details for Web of Science ID A1990EF61000007

  View details for PubMedID 2250058

• BONE LYSIS IN WELL-FIXED CEMENTED FEMORAL COMPONENTS JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Maloney, W. J., Jasty, M., Rosenberg, A., Harris, W. H. 1990; 72 (6): 966-970

  Abstract

  We have reviewed 25 cases of focal femoral osteolysis in radiographically stable, cemented femoral implants. In three hips retrieved at post-mortem from two patients, we have been able to make a detailed biomechanical and histological analysis. The interval between arthroplasty and the appearance of focal osteolysis on clinical radiographs ranged from 40 to 168 months, and in over 70% of the cases this did not appear until after five or more years. Few had significant pain and there was no relation to age, sex or original diagnosis. The most common site for osteolysis were Gruen zones 2 and 3 on the anteroposterior radiograph and zones 5 and 6 on the lateral radiograph. In 15 cases (60%), the area of osteolysis corresponded to either a defect in the cement mantle or an area of very thin cement. The rate of progression of these lesions was variable, but to date only one has progressed to gross loosening of the femoral component. The back-scatter scanning electron microscopic examination of serial sections and biomechanical testing of the post-mortem specimens demonstrated focal cement fracture around implants that were otherwise rigidly fixed. In eight cases from which tissue was available, histology showed a histiocytic reaction with evidence of particulate polymethylmethacrylate. We consider that this local fragmentation was the stimulus for local osteolysis in an otherwise stable cemented femoral component.

  View details for Web of Science ID A1990EG84200003

  View details for PubMedID 2246299

• COMPARISON OF A HYBRID WITH AN UNCEMENTED TOTAL HIP-REPLACEMENT - A RETROSPECTIVE MATCHED-PAIR STUDY JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Harris, W. H. 1990; 72A (9): 1349-1352

  Abstract

  The efficacy of a type of uncemented total hip replacement was compared with that of a hybrid total hip replacement in which an uncemented acetabular and a cemented femoral component were used. Twenty-five patients who had had a hybrid total hip replacement were matched, by age, weight, sex, and diagnosis, with twenty-five patients who had had an uncemented total hip replacement. All of the operations were done by one surgeon, who used the same operative approach and the same regimen of postoperative rehabilitation. All of the patients were followed for at least two years. The mean postoperative hip score was 96 points for the hybrid group and 84 points for the cementless group (p less than 0.02). Twenty-four (96 per cent) of the patients who had a hybrid prosthesis reported no or only slight pain postoperatively. In the uncemented group, of the six patients (24 per cent) who reported mild to severe pain, five had pain in the thigh, a limp occurred more frequently, five femoral components had migrated, and four hips needed reoperation. The results with the hybrid replacement that had a cemented femoral component were superior to those with the uncemented femoral component over the relatively brief period for which these patients were followed.

  View details for Web of Science ID A1990EE78100011

• Histomorphological studies of the long-term skeletal responses to well fixed cemented femoral components. journal of bone and joint surgery. American volume Jasty, M., Maloney, W. J., Bragdon, C. R., HAIRE, T., Harris, W. H. 1990; 72 (8): 1220-1229

  Abstract

  Thirteen femora that were obtained at autopsy from patients in whom a cemented total hip replacement had been implanted from forty months to 17.5 years earlier were evaluated radiographically and morphologically. All of the patients had been functioning well, and only one of the prostheses showed radiographic evidence of loosening. Serial sections of the proximal portion of the femur that enclosed the femoral component of the prosthesis showed that the host bone was intimately and directly apposed to the cement, and fibrous tissue intervened only rarely. The bone-remodeling processes had created a dense shell of substantial new bone around the cement-mantle that resembled a new cortex, attached to the outer cortex by new trabecular struts. Evidence of ingrowth of bone from this dense shell of bone into the undulating surface of the cement was found in many areas. In the adjacent femoral cortex, there was substantial osteoporosis and cortical thinning. The cement-bone interface was intact and excellent throughout, despite the presence of fractures within the cement-mantle and de-bonding at the cement-prosthesis interface in some specimens. The cemented femoral components were well tolerated by the skeleton over a long period of use, and fibrous tissue had rarely formed at the femoral cement-bone interface of these well fixed and clinically successful prostheses. The cement-mantle was well supported by extensive medullary bone-remodeling and formation of a dense shell of new bone. The internal bone-remodeling helped to maintain the cemented femoral components over time and did not cause loosening of the prosthesis.

  View details for PubMedID 2398093

• HISTOMORPHOLOGICAL STUDIES OF THE LONG-TERM SKELETAL RESPONSES TO WELL FIXED CEMENTED FEMORAL COMPONENTS JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Jasty, M., Maloney, W. J., Bragdon, C. R., HAIRE, T., Harris, W. H. 1990; 72A (8): 1220-1229

  View details for Web of Science ID A1990EA36200015

• B-MODE ULTRASOUND SCANNING IN THE DETECTION OF PROXIMAL VENOUS THROMBOSIS AFTER TOTAL HIP-REPLACEMENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Woolson, S. T., MCCRORY, D. W., Walter, J. F., Maloney, W. J., Watt, J. M., CAHILL, P. D. 1990; 72A (7): 983-987

  View details for Web of Science ID A1990DV43200004

• ENDOSTEAL EROSION IN ASSOCIATION WITH STABLE UNCEMENTED FEMORAL COMPONENTS JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Maloney, W. J., Jasty, M., Harris, W. H., Galante, J. O., Callaghan, J. J. 1990; 72A (7): 1025-1034

  View details for Web of Science ID A1990DV43200011

• Endosteal erosion in association with stable uncemented femoral components. journal of bone and joint surgery. American volume Maloney, W. J., Jasty, M., Harris, W. H., Galante, J. O., Callaghan, J. J. 1990; 72 (7): 1025-1034

  Abstract

  Sixteen cases of patients who had focal femoral osteolysis after total hip replacement without cement were identified. Fourteen of them were included in a retrospective review of 474 consecutive total hip replacements without cement in 441 patients who had been followed for at least two years. The criteria for inclusion in the study were focal osteolysis with a femoral component that appeared stable radiographically, and no subsidence or change of position of the implant. All but two patients were men and were quite active. The average age was forty-seven years (range, twenty to sixty-five years). Fourteen of the sixteen patients had an excellent clinical result (a Harris hip score of 90 points or more). In two patients, the hip replacement was revised and, in a third, a biopsy was done. In all three patients, the implant was found to be firmly fixed to the femur. In the two hips that were revised, extensive ingrowth of bone was demonstrated histologically, there was no evidence of infection, and a well defined fibrous membrane was found around the smooth portion of the stem. The histological specimens from these two hips contained focal aggregates of macrophages with particulate polyethylene and metallic debris. In the biopsy material from the hip that was not revised, a fine fibrous membrane lined a cystic cavity. Although the membrane contained an occasional macrophage, no foreign material was identified. Trabecular microfracture and osteoclastic resorption of bone were seen next to the fibrous lining. With one exception, osteolysis was not identified less than two years postoperatively. In most patients, osteolysis appeared after three years. This study showed that femoral osteolysis can occur around uncemented components.

  View details for PubMedID 2384501

• B-mode ultrasound scanning in the detection of proximal venous thrombosis after total hip replacement. journal of bone and joint surgery. American volume Woolson, S. T., MCCRORY, D. W., Walter, J. F., Maloney, W. J., Watt, J. M., CAHILL, P. D. 1990; 72 (7): 983-987

  Abstract

  A prospective study of the accuracy of real-time B-mode ultrasonography in detecting deep venous thrombosis in the femoral and popliteal veins of the lower extremity was conducted on a consecutive series of patients who had had a total hip replacement. Ascending venography was used as a diagnostic standard. One hundred and forty-three patients had ultrasound studies of both lower extremities and a venographic study of the operatively treated lower extremity at an average of 7.6 days postoperatively. The two tests were done within twenty-four hours of each other. Both ultrasonography and venography were done on 152 extremities. Two paired studies were excluded from the analysis of results because the ultrasound scans could not be interpreted. In 131 extremities, both diagnostic tests were negative for proximal thrombosis. Eight extremities had isolated thrombosis of a vein in the calf that was detected only by venography. In nineteen extremities, old or fresh thrombosis was diagnosed by venography. In four extremities, an old thrombosis of the superficial femoral vein was detected by both studies. In four of the extremities that had a new thrombus in the common femoral vein and in nine that had a new thrombus in the superficial femoral vein, abnormal findings on ultrasound scans correlated with those on venograms. There were two false-negative ultrasound scans and one false-negative venogram. The sensitivity, specificity, and accuracy of ultrasonography were 89, 100, and 99 per cent for the diagnosis of thrombosis of the proximal veins of the lower limb and 63, 100, and 93 per cent for the diagnosis of thrombosis when the entire venous system of the limb was included.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 2200790

• THE INFLUENCE OF CONTINUOUS PASSIVE MOTION ON OUTCOME IN TOTAL KNEE ARTHROPLASTY CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Schurman, D. J., HANGEN, D., Goodman, S. B., Edworthy, S., Bloch, D. A. 1990: 162-168

  Abstract

  All primary condylar total knee replacement arthroplasties (TKAs) performed from 1977 to 1984 at the authors' institution were divided into two groups based on the use of continuous passive motion (CPM) in the immediate postoperative period. The control group consisted of 73 patients who were treated with 95 TKAs without postoperative CPM. The average age was 65.4 years. The study group consisted of 38 patients who had 51 TKAs in which CPM was used postoperatively. The mean patient age was 62.8 years. The most common diagnoses in both groups were osteoarthritis and rheumatoid arthritis. Range of motion (ROM) was recorded preoperatively, at discharge, at three months, one year, two years, and at the last follow-up visit. There were no statistically significant differences in the ROM between the two groups at any of these time periods. At two years, the mean flexion and extension in the study group were 99 degrees and -4 degrees, respectively, compared to 103 degrees and -5 degrees in the control group. The average hospital stay was 11.2 days in the study group, whereas it was 15.1 days in control group. In the control group, there was one superficial infection, no deep infections, and four pulmonary emboli compared with three superficial infections, two deep infections, and no pulmonary emboli in the study group. There was no difference in the transfusion requirements between the two groups. CPM is advocated by the authors to help achieve discharge ROM earlier, but the protocol has been changed to begin CPM on the second postoperative day to allow the wound to stabilize.

  View details for Web of Science ID A1990DM91300023

  View details for PubMedID 2364605

• HYBRID TOTAL HIP-ARTHROPLASTY CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Harris, W. H., Maloney, W. J. 1989: 21-29

  Abstract

  One hundred twenty-six primary total hip arthroplasties composed of a hybrid cemented femoral component and a cementless acetabular component were followed for a minimum of two years (mean, 42 months). The average patient age was 63 years. The most common diagnosis was osteoarthritis (85 hips), although 13 of the cases were severe or total congenital dislocations. Overall, the results were excellent. The mean Harris hip score was 93. Postoperative pain was rated as none or slight in 94% of the cases. No patient had moderate or severe pain. No femoral or acetabular components were revised. Roentgenographically no femoral component was definitely or probably loose. One acetabular reconstruction component had migrated. The authors conclude that the selective use of cemented and cementless fixation by anatomic site in this hybrid form of hip arthroplasty provided excellent results for five and one-half years.

  View details for Web of Science ID A1989CC62800004

  View details for PubMedID 2582670

• BIOMECHANICAL AND HISTOLOGIC INVESTIGATION OF CEMENTED TOTAL HIP ARTHROPLASTIES - A STUDY OF AUTOPSY-RETRIEVED FEMURS AFTER INVIVO CYCLING CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Jasty, M., Burke, D. W., OCONNOR, D. O., ZALENSKI, E. B., Bragdon, C., Harris, W. H. 1989: 129-140

  Abstract

  Eleven whole anatomic specimens of the femur were retrieved at autopsy from patients who previously had cemented total hip arthroplasty. Implant duration ranged from 0.5 to 210 months. Clinically and roentgenographically the implants were stable. A detailed biomechanical analysis evaluated bone strains and implant stability in both the single-limb stance and stair-climbing positions using a 100-pound spinal load. The stability offered by cement in these well-fixed prostheses was remarkable, with the maximum axial micromotion being 40 mu. This is a reflection of intimate osseointegration at the bone-cement interface with only rare intervening fibrous tissue. The strain gauge and photoelastic strain-coating studies revealed that marked stress shielding in the proximal medial femoral cortex persists long after a cemented femoral component is inserted. Even 17 years after surgery, the strain in the calcar region did not normalize.

  View details for Web of Science ID A1989CC62800015

  View details for PubMedID 2582664

• External iliac arteriovenous fistula following total hip arthroplasty. A case report. journal of arthroplasty Woolson, S. T., Maloney, W. J., Tanner, J. B. 1989; 4 (3): 281-284

  Abstract

  An external iliac arteriovenous fistula developed 3 years after revision of the acetabular component of a total hip arthroplasty in a patient with rheumatoid arthritis. The mechanism of this complication, which also produced disseminated intravascular coagulopathy, was chronic erosion of the iliac artery from a large bolus of bone cement and/or the protrusio shell that were used to reconstruct a severe acetabular protrusio. Care must be taken to avoid intrapelvic intrusion of hardware or cement during acetabular reconstruction to avoid immediate and late injury to the iliac vessels.

  View details for PubMedID 2795035

• CAST IMMOBILIZATION AFTER TOTAL ELBOW ARTHROPLASTY - A SAFE COST-EFFECTIVE METHOD OF INITIAL POSTOPERATIVE CARE CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Schurman, D. J. 1989: 117-122

  Abstract

  Seventeen nonconstrained total elbow replacements were inserted in 12 patients. One patient died prior to the one-year follow-up examination, and two others required revision in the immediate postoperative period. The remaining 14 primary total elbow arthroplasties in 11 patients were included in this study. There were eight women and three men with an average age of 58.1 years. The diagnosis was rheumatoid arthritis in 12 patients and posttraumatic arthritis and juvenile rheumatoid arthritis each in one patient. Postoperatively, patients were immobilized in a long arm cast. The mean hospital stay was 4.3 days. At four weeks, the patients were seen for cast removal. Instructions were given for range of motion (ROM) exercises and patients were encouraged to resume normal daily activities as tolerated. No formal physical therapy was prescribed. The average follow-up period was 32 months. Preoperatively, the mean elbow motions were flexion 124 degrees, extension 34 degrees, pronation 65 degrees, and supination 44 degrees. At the last follow-up examination, ROM had improved significantly in all directions except extension (flexion 141 degrees, extension 36 degrees, pronation 77 degrees, and supination 61 degrees). There was one ulnar nerve palsy that only partially resolved. Another patient's elbow had initially subluxed due to excessive shortening of the humerus; however, he had an excellent ROM and was asymptomatic at 31 months. There were no dislocations or wound healing problems. Cast immobilization provides an effective means of promoting soft-tissue healing, permitting early discharge from the hospital and simplifying the postoperative rehabilitation while achieving satisfactory ROM without formal physical therapy.

  View details for Web of Science ID A1989AJ74100018

  View details for PubMedID 2752611

• DIGIT REPLANTATION APPLYING THE LEECH HIRUDO-MEDICINALIS CLINICAL ORTHOPAEDICS AND RELATED RESEARCH BRODY, G. A., Maloney, W. J., Hentz, V. R. 1989: 133-137

  Abstract

  Digits that were formerly assessed as nonreplantable may now be replanted with the help of the leech Hirudo medicinalis. The early experience with a series of patients who had relative contraindications for replantation is reported. In each case, venous repair was either marginal or technically impossible. Postoperative venous congestion developed following replantation and was treated with the application of medicinal leeches. Patient acceptance was high, and no infections developed. No patient required transfusion. The authors conclude that the use of medicinal leeches shows promise as a safe and effective method of providing temporary venous drainage in replanted digits.

  View details for Web of Science ID A1989AJ74100020

  View details for PubMedID 2752613

• UNUNITED LOWER-LIMB FRACTURES WESTERN JOURNAL OF MEDICINE CSONGRADI, J. J., Maloney, W. J. 1989; 150 (6): 675-680

  Abstract

  Nonunion is a fairly common complication of fracture management, with an overall rate of about 3% for the skeleton as a whole and 9% for the tibia. High-energy injury fractures have a nonunion rate as high as 75%. Other factors that may lead to nonunion are inappropriate treatment, infection, and preexisting disease. The diagnosis of nonunion is based largely on clinical examination. Plain radiographs and tomograms, computed tomograms, and contrast imaging may be used to confirm nonhealing. Radionuclide imaging can help determine the presence of infection, an impaired blood supply, or impaired osteogenic activity at the fracture site. The treatment of ununited fractures is based on the principles of good fracture management: adequate immobilization, asepsis and soft tissue cover, osteoconduction (bone contact), osteoinduction (stimulation of bone growth), and metabolic well-being. New modalities for osteoinduction are promising adjuncts to standard treatment, the autogenous bone graft, but conclusive proof of efficacy in humans does not yet exist.

  View details for Web of Science ID A1989AB02300005

  View details for PubMedID 2665320

• BENIGN METASTASIZING GIANT-CELL TUMOR OF BONE - REPORT OF 3 CASES AND REVIEW OF THE LITERATURE CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Maloney, W. J., Vaughan, L. M., Jones, H. H., Ross, J., Nagel, D. A. 1989: 208-215

  Abstract

  Three cases of benign giant-cell tumor (GCT) of bone with pulmonary metastasis are reported. In addition, 28 cases from the literature are reviewed. The patients were followed for a mean of 7.8 years (range from two to 29 years). The interval to metastasis ranged from zero to ten years with a mean of 3.2 years. Metastasis was not related to the number of previous operations. The local recurrence rate in the tumors that metastasized was 63%, suggesting that GCTs that metastasize may be an aggressive form of the tumor. The overall mortality rate was 16%. Persistent pulmonary disease does not carry a poor prognosis; surgical resection of accessible pulmonary nodules is recommended to provide histologic confirmation of the diagnosis, and prevent future complications secondary to local growth of the implants, as well as provide a potential cure. Chemotherapy has not improved survival and is associated with significant morbidity and is thus not recommended. Adjuvant radiation is recommended only for control of surgically unresectable lesions because of its potential association with sarcomatous degeneration in GCT.

  View details for Web of Science ID A1989U954000033

  View details for PubMedID 2656024

• SUPERFICIAL FEMORAL PSEUDOANEURYSM AND ARTERIAL THROMBOEMBOLISM CAUSED BY AN OSTEOCHONDROMA JOURNAL OF PEDIATRIC ORTHOPAEDICS Woolson, S. T., Maloney, W. J., James, D. R. 1989; 9 (3): 335-337

  Abstract

  A 13-year-old boy with a symptomatic distal femoral osteochondroma was found to have a pseudoaneurysm of the superficial femoral artery caused by the tumor and occlusion of the anterior tibial artery due to arterial thromboembolism. Excision of the exostosis followed by saphenous vein grafting resulted in an excellent clinical recovery.

  View details for Web of Science ID A1989U380200014

  View details for PubMedID 2723054

• Time-related improvement in the range of motion of the hip after total replacement. journal of bone and joint surgery. American volume Woolson, S. T., Maloney, W. J., Schurman, D. J. 1985; 67 (8): 1251-1254

  Abstract

  We studied the progression of improvement in the range of motion of the hip after total hip replacement as it was related to time postoperatively. One hundred and eight hip replacements performed by members of the Stanford University Division of Orthopaedic Surgery in ninety-two patients were included in the analysis. The hips had no major postoperative complications, and the range of motion was examined preoperatively; at six months, one year, and two years, postoperatively; and at a last follow-up examination at a minimum of 4.5 years. There was no statistically significant improvement in the flexion and abduction of the hip after the one-year follow-up visit, but adduction and internal and external rotation were improved significantly at the last follow-up (average, 7.5 years). Of multiple variables that were studied, including those related to the patient, to the size and design of the prosthesis, and to the orientation of the total hip components, only the preoperative range of motion of the hip and a history of previous surgical treatment were major determining factors in the postoperative improvement of the range of motion.

  View details for PubMedID 4055850

• TIME-RELATED IMPROVEMENT IN THE RANGE OF MOTION OF THE HIP AFTER TOTAL REPLACEMENT JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Woolson, S. T., Maloney, W. J., Schurman, D. J. 1985; 67A (8): 1251-1254

  View details for Web of Science ID A1985ATF8600017

• Methemoglobinemia in an infant. Arizona medicine Maloney, W. J., MACFARLANE, M. T., Rimsza, M. E. 1983; 40 (10): 700-702

  View details for PubMedID 6651539