Tim Wang, M.D. is an Orthopaedic Surgeon at Stanford Healthcare specializing in Sports Medicine. Dr. Wang sees patients and performs surgeries at the Stanford Medicine Outpatient Center in Redwood City and Stanford Healthcare in Emeryville.
Dr. Wang’s clinical expertise includes the management of sports injuries of the knee, shoulder, and elbow using the most innovative arthroscopic and minimally invasive techniques. He has particular interest in knee cartilage regeneration, cartilage transplantation, and knee ligament reconstruction. He also provides comprehensive shoulder care (including rotator cuff tears and shoulder replacement), as well as treats fractures of the upper and lower extremities.
Originally from Chicago, Dr. Wang recognized his passion for medicine early in his career and committed to the Honors Program in Medical Education at Northwestern University. He continued his training at the Northwestern University Feinberg School of Medicine. In recognition of his academic achievements, Dr. Wang was elected to the Alpha Omega Alpha honors society and also received his medical degree with Distinction in Research. He completed his orthopaedic surgery residency at Stanford University and went on to pursue subspecialty training in Sports Medicine and Shoulder Surgery at the Hospital for Special Surgery in New York, the top ranked Orthopaedic hospital in the nation. While in New York, he served as the Clinical Fellow for the Brooklyn Nets NBA team and Iona College athletics (NCAA DI MAAC). Dr. Wang has participated in the care of countless collegiate and professional athletes. He currently serves as Team Physician for Laney College and Merritt College in Oakland.
FOR MORE INFORMATION, PLEASE GO TO: www.timwangmd.com
- Orthopaedic Surgery
- Sports Medicine
- Knee Surgery
- Shoulder Surgery
Clinical Assistant Professor, Orthopaedic Surgery
Board Certification: American Board of Orthopaedic Surgery, Sports Medicine (2020)
Subspecialty Board Certification, American Board of Orthopaedic Surgery, Orthopaedic Sports Medicine (2020)
Board Certification: American Board of Orthopaedic Surgery, Orthopaedic Surgery (2019)
Fellowship: Hospital for Special Surgery and Cornell Univ Med Coll (2017) NY
Residency: Stanford University Orthopaedics (2016) CA
Medical Education: Northwestern University Feinberg School of Medicine (2011) IL
- Clinical and MRI Outcomes of Fresh Osteochondral Allograft Transplantation After Failed Cartilage Repair Surgery in the Knee (vol 100, pg 1949, 2018) JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME 2019; 101 (2)
Patellofemoral Cartilage Lesions Treated With Particulated Juvenile Allograft Cartilage: A Prospective Study With Minimum 2-Year Clinical and Magnetic Resonance Imaging Outcomes
ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY
2018; 34 (5): 1498–1505
To analyze the functional outcomes of patients treated with particulated juvenile articular cartilage (PJAC) for symptomatic articular cartilage lesions in the patellofemoral joint, correlates clinical outcomes with magnetic resonance imaging (MRI) appearance of the repair tissue using cartilage-sensitive quantitative T2-mapping.All patients treated with PJAC for patellofemoral lesions were identified and prospectively followed with clinical outcome scores (International Knee Documentation Committee [IKDC], Knee Outcome Survey-Activities of Daily Living [KOS-ADL], and Marx Activity Scale [MAS]). Postoperative MRI scans using quantitative T2 mapping were obtained and interpreted by an independent musculoskeletal radiologist.Twenty-seven patients treated with PJAC for 30 full-thickness patellofemoral cartilage lesions were identified; mean postoperative follow-up was 3.84 years. Improvements from pre- to postoperative mean IKDC (45.9 vs 71.2, P < .001) and KOS-ADL (60.7 vs 78.8, P < .001) scores were observed; no significant change in MAS was seen (7.04 vs 7.17, P = .97). Advanced age, history of previous surgery, lesion location (patella vs trochlea), or concomitant tibial tubercle osteotomy did not affect outcome scores. Greater body mass index was associated with less improvement in KOS-ADL score. No patients required reoperation for graft-related issues. Lesion fill exceeding 67% by MRI assessment was noted in 69.2% of lesions; depth of lesion fill did not correlate with clinical outcomes. Quantitative T2-mapping revealed prolonged relaxation time at the graft site compared with adjacent normal cartilage at both deep and superficial zones.This study found significantly improved pain and function in patients treated with PJAC for symptomatic patellofemoral articular cartilage defects. No patients required reoperation for graft-related issues. Postoperative MRI revealed majority lesion fill in more than 69% of patients, but persistent morphologic differences between graft site and normal adjacent cartilage remain. Though we support PJAC use in this setting to improve patient subjective outcomes, improved appearance on postoperative imaging was not found to provide additional clinical benefit.Level IV, case series.
View details for DOI 10.1016/j.arthro.2017.11.021
View details for Web of Science ID 000432162600025
View details for PubMedID 29395552
Partial and Full-Thickness RCT: Modern Repair Techniques
CURRENT REVIEWS IN MUSCULOSKELETAL MEDICINE
2018; 11 (1): 113–21
The purpose of this article is to review the recent literature concerning modern repair techniques related to partial- and full-thickness rotator cuff tears.The understanding of rotator cuff pathology and healing continues to evolve, beginning with emerging descriptions of the anatomic footprint and natural history of rotator cuff tears. Significant controversy remains in treatment indications for partial-thickness rotator cuff lesions as well as optimal surgical repair techniques for both partial- and full-thickness tears. Techniques such as margin convergence and reduction of the so-called "comma" tissue have improved the ability to anatomically reduce large and retracted tears. Repair strength and contact pressures are improved with double-row repairs and transosseus-equivalent techniques compared to traditional single-row repairs. Future work is directed towards obtaining reliable radiographic healing and demonstrating clinical superiority and cost-effectiveness of a single technique. Much recent work regarding rotator cuff anatomy and pathology has been reported. Newer techniques improve repair strength. Despite these advances, significant questions remain concerning surgical indications and clinical outcomes.
View details for PubMedID 29356951
Osteochondral Allograft Transplantation of the Knee in Patients Aged 40 Years and Older
AMERICAN JOURNAL OF SPORTS MEDICINE
2018; 46 (3): 581–89
Treatment of large chondral defects of the knee among patients aged ≥40 years remains a difficult clinical challenge owing to preexisting joint degeneration and the lack of treatment options short of arthroplasty.To characterize the survivorship, predictors of failure, and clinical outcomes of osteochondral allograft transplantation (OCA) of the knee among patients aged ≥40 years.Case series; Level of evidence, 4.Prospectively collected data were reviewed for 54 consecutive patients aged ≥40 years who were treated with OCA. Preoperative levels of osteoarthritis (according to Kellgren-Lawrence classification) and meniscal volume and quality were graded from review of radiographs and magnetic resonance imaging. Complications, reoperations, and patient responses to validated outcome measures were reviewed. A minimum follow-up of 2 years was required for analysis. Failure was defined by any removal or revision of the allograft or conversion to arthroplasty.Among 51 patients (mean age, 48 years; range, 40-63 years; 65% male), a total of 52 knees had symptomatic focal cartilage lesions (up to 2 affected areas) that were classified as Outerbridge grade 4 at the time of OCA and did not involve substantial bone loss requiring shell allografts or additional bone grafting. Mean duration of follow-up was 3.6 years (range, 2-11 years). After OCA, 21 knees (40%) underwent reoperation, including 14 failures (27%) consisting of revision OCA (n = 1), unicompartmental knee arthroplasty (n = 5), and total knee arthroplasty (n = 8). Mean time to failure was 33 months, and 2- and 4-year survivorship rates were 88% and 73%, respectively. Male sex (hazard ratio = 4.18, 95% CI = 1.12-27.13) and a higher number of previous ipsilateral knee operations (hazard ratio = 1.70 per increase in 1 surgical procedure, 95% CI = 1.03-2.83) were predictors of failure. A higher Kellgren-Lawrence osteoarthritis grade on preoperative radiographs was associated with higher failure rates in the Kaplan-Meier analysis but not the multivariate model. At final follow-up, clinically significant improvements were noted in the pain (mean score, 47.8 to 67.6) and physical functioning (56.8 to 79.1) subscales of the Short Form-36, as well as the International Knee Documentation Committee subjective form (45.0 to 63.6), Knee Outcome Survey-Activities of Daily Living (64.5 to 80.1), and overall condition statement (4.5 to 6.8) ( P < .001). No significant changes were noted for the Marx Activity Rating Scale (5.1 to 3.9, P = .789).A higher failure rate was found in this series of patients aged ≥40 years who were treated with OCA as compared with other studies of younger populations. However, for select older patients, OCA can be a good midterm treatment option for cartilage defects of the knee.
View details for DOI 10.1177/0363546517741465
View details for Web of Science ID 000429453800008
View details for PubMedID 29185781
Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched- Group Analysis With Minimum 2-Year Follow-Up
ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY
2017; 33 (12): 2198–2207
To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up.After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm2 in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure.A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups.OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes.Level III, retrospective comparative study.
View details for DOI 10.1016/j.arthro.2017.06.034
View details for Web of Science ID 000416693000025
View details for PubMedID 28800919
Posterior Glenoid Wear in Total Shoulder Arthroplasty: Eccentric Anterior Reaming Is Superior to Posterior Augment
CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
2015; 473 (12): 3928-3936
Uncorrected glenoid retroversion during total shoulder arthroplasty may lead to an increased likelihood of glenoid prosthetic loosening. Augmented glenoid components seek to correct retroversion to address posterior glenoid bone loss, but few biomechanical studies have evaluated their performance.We compared the use of augmented glenoid components with eccentric reaming with standard glenoid components in a posterior glenoid wear model. The primary outcome for biomechanical stability in this model was assessed by (1) implant edge displacement in superior and inferior edge loading at intervals up to 100,000 cycles, with secondary outcomes including (2) implant edge load during superior and inferior translation at intervals up to 100,000 cycles, and (3) incidence of glenoid fracture during implant preparation and after cyclic loading.A 12°-posterior glenoid defect was created in 12 composite scapulae, and the specimens were divided in two equal groups. In the posterior augment group, glenoid version was corrected to 8° and an 8°-augmented polyethylene glenoid component was placed. In the eccentric reaming group, anterior glenoid reaming was performed to neutral version and a standard polyethylene glenoid component was placed. Specimens were cyclically loaded in the superoinferior direction to 100,000 cycles. Superior and inferior glenoid edge displacements were recorded.Surviving specimens in the posterior augment group showed greater displacement than the eccentric reaming group of superior (1.01 ± 0.02 [95% CI, 0.89-1.13] versus 0.83 ± 0.10 [95% CI, 0.72-0.94 mm]; mean difference, 0.18 mm; p = 0.025) and inferior markers (1.36 ± 0.05 [95% CI, 1.24-1.48] versus 1.20 ± 0.09 [95% CI, 1.09-1.32 mm]; mean difference, 0.16 mm; p = 0.038) during superior edge loading and greater displacement of the superior marker during inferior edge loading (1.44 ± 0.06 [95% CI, 1.28-1.59] versus 1.16 ± 0.11 [95% CI, 1.02-1.30 mm]; mean difference, 0.28 mm; p = 0.009) at 100,000 cycles. No difference was seen with the inferior marker during inferior edge loading (0.93 ± 0.15 [95% CI, 0.56-1.29] versus 0.78 ± 0.06 [95% CI, 0.70-0.85 mm]; mean difference, 0.15 mm; p = 0.079). No differences in implant edge load were seen during superior and inferior loading. There were no instances of glenoid vault fracture in either group during implant preparation; however, a greater number of specimens in the eccentric reaming group were able to achieve the final 100,000 time without catastrophic fracture than those in the posterior augment group.When addressing posterior glenoid wear in surrogate scapula models, use of angle-backed augmented glenoid components results in accelerated implant loosening compared with neutral-version glenoid after eccentric reaming, as shown by increased implant edge displacement at analogous times.Angle-backed components may introduce shear stress and potentially compromise stability. Additional in vitro and comparative long-term clinical followup studies are needed to further evaluate this component design.
View details for DOI 10.1007/s11999-015-4482-8
View details for PubMedID 26242283
Reoperation Rates following Meniscus Transplantation using the Truven Database.
Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association
The purpose of this study was to determine the (1) reoperation rate and (2) 30-day complication rate in a large insurance database.The Truven Database was queried for subjects that underwent meniscus allograft transplantation (CPT code 29868) in the outpatient setting with minimal two year follow up. Patients without confirmed laterality and patients that underwent concomitant ligament reconstruction were excluded. Reoperation was defined by ipsilateral knee procedure after the index surgery. The 30-day postoperative complication rates were assessed using ICD-9-CM codes.284 patients (mean age of 26.2 ± 10.4 years old and 49.6% females) were included in this study with mean follow up of 43.2 ± 19.2 months. One hundred and sixty seven subjects (58.8%) undergoing meniscus allograft transplantation underwent reoperation at an average of 11.9 ± 12.2 months postoperatively. There was a low number of subjects that required ipsilateral unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) postoperatively (0.7% and 1.1%, respectively). The overall 30-day complication rate following meniscus allograft transplantation was 1.4%.Patients undergoing meniscus allograft transplantation have a 58.8% reoperation rate at final follow up with low (1.4%) 30-day complication rates in a large insurance database.
View details for DOI 10.1016/j.arthro.2020.06.031
View details for PubMedID 32645340
Decreased estimated blood loss in lateral trans-psoas versus anterior approach to lumbar interbody fusion for degenerative spondylolisthesis.
Journal of spine surgery (Hong Kong)
2019; 5 (2): 185–93
Background: The goal of the current study was to compare the perioperative and post-operative outcomes of eXtreme lateral trans-psoas approach (XLIF) versus anterior lumbar interbody fusion (ALIF) for single level degenerative spondylolisthesis. The ideal approach for degenerative spondylolisthesis remains controversial.Methods: Consecutive patients undergoing single level XLIF (n=21) or ALIF (n=54) for L4-5 degenerative spondylolisthesis between 2008-2012 from a single academic center were retrospectively reviewed. Groups were compared for peri-operative data (estimated blood loss, operative time, adjunct procedures or additional implants), radiographic measurements (L1-S1 cobb angle, disc height, fusion grade, subsidence), 30-day complications (infection, DVT/PE, weakness/paresthesia, etc.), and patient reported outcomes (leg and back Numerical Rating Scale, and Oswestry Disability Index).Results: Estimated blood loss was significantly lower for XLIF [median 100; interquartile range (IQR), 50-100 mL] than for ALIF (median 250; IQR, 150-400 mL; P<0.001), including after adjusting for significantly higher rates of posterior decompression in the ALIF group. There were no significant differences in rates of complications within 30 days, radiographic outcomes, or in re-operation rates. Both groups experienced significant pain relief post-operatively.Conclusions: The lateral trans-psoas approach is associated with diminished blood loss compared to the anterior approach in the treatment of degenerative spondylolisthesis. We were unable to detect differences in radiographic outcomes, complication rates, or patient reported outcomes. Continued efforts to directly compare approaches for specific indications will minimize complications and improve outcomes. Further studies will continue to define indications for lateral versus anterior approach to lumbar spine for degenerative spondylolisthesis.
View details for DOI 10.21037/jss.2019.05.08
View details for PubMedID 31380471
Clinical and MRI Outcomes of Fresh Osteochondral Allograft Transplantation After Failed Cartilage Repair Surgery in the Knee
JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME
2018; 100 (22): 1949–59
Fresh osteochondral allograft transplantation is an appealing option to address a failed cartilage repair surgical procedure, given the ability to treat large lesions and to address the subchondral osseous changes commonly seen in the revision setting. We hypothesized that osteochondral allograft transplantation after failed cartilage repair would result in low failure rates and improved function and that improved graft incorporation on postoperative magnetic resonance imaging (MRI) would correlate with a superior clinical outcome.A retrospective review of prospectively collected data was used to identify 43 patients treated with fresh osteochondral allograft transplantation after a previous cartilage repair surgical procedure and having a minimum follow-up of 2 years. Clinical outcomes were evaluated using the Short Form-36 (SF-36) score, International Knee Documentation Committee (IKDC) Subjective Knee Score, Marx Activity Scale, Knee Outcome Survey-Activities of Daily Living (KOS-ADL) Questionnaire, Cincinnati Sports Activity Score, and Cincinnati Overall Symptom Assessment. Postoperative MRI scans were obtained at a mean time of 19.7 months and were independently reviewed by a musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS).At a mean 3.5-year follow-up after osteochondral allograft transplantation, significant improvements (p < 0.05) in SF-36 Physical Function, SF-36 Pain, KOS-ADL, IKDC Subjective Knee Score, and Cincinnati Overall Symptom Assessment were seen. Over 90% of grafts remained in situ at the time of the latest follow-up, although 17 knees (40%) underwent reoperation, the majority for arthroscopic debridement or manipulation for stiffness. Body mass index (BMI) of >30 kg/m was associated with worse clinical outcomes. The mean total OCAMRISS score demonstrated poorer allograft integration in patients with graft failure, but the total score did not meaningfully correlate with clinical outcome scores. However, better individual articular cartilage appearance and osseous integration subscores were associated with better clinical outcome scores.Significant improvements in pain and function were seen following fresh osteochondral allograft transplantation after failed cartilage repair, with an overall graft survival rate of >90%. Patients with greater bone and cartilage incorporation on MRI had superior clinical outcomes, although persistent osseous edema was frequently seen. We concluded that osteochondral allograft transplantation is an effective salvage treatment after failed cartilage repair and recommend further evaluation of techniques to optimize graft integration.Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
View details for DOI 10.2106/JBJS.17.01418
View details for Web of Science ID 000452184200011
View details for PubMedID 30480599
Abundant heterotopic bone formation following use of rhBMP-2 in the treatment of acetabular bone defects during revision hip arthroplasty.
2018; 4 (2): 162–68
Revision hip arthroplasty in the setting of periacetabular bone loss presents a significant challenge, as options for restoring bone loss are limited. Recombinant human bone morphogenetic protein-2 may offer a solution by promoting bone growth to restore bone stock before implant reimplantation. Here we present a case of a patient with a periprosthetic acetabulum fracture, resulting in pelvic discontinuity as the result of significant periacetabular bone loss. Using a staged approach, periacetabular bone stock was nearly entirely reconstituted using recombinant BMPs and allograft, which resulted in stable fixation, but with abundant heterotopic bone formation. Recombinant BMP-2 offers a useful tool for restoring bone stock in complex hip arthroplasty revision cases with periacetabular bone loss; however, caution must be used as overabundant bone growth as heterotopic ossification may result.
View details for PubMedID 29896546
Return to play and performance after anterior cruciate ligament reconstruction in the National Basketball Association: surgeon case series and literature review
PHYSICIAN AND SPORTSMEDICINE
2017; 45 (3): 303–8
To investigate return to play (RTP) and functional performance after anterior cruciate ligament reconstruction (ACLR) in National Basketball Association (NBA) players and to perform a systematic review of the literature to understand RTP after ACLR in professional basketball.NBA players undergoing ACLR between 2008 and 2014 by two surgeons were identified. RTP and performance were assessed based on a review of publically available statistics. A systematic review of the literature was performed using the MEDLINE database. Inclusion criteria were: English language, ACL surgery outcome, professional basketball and RTP outcome. We reviewed studies for RTP rates and RTP performance.Our study included 12 professional basketball players with NBA level experience. Eleven of the 12 players returned to their prior level of play. Eight of the 9 (88.9%) players actively playing in the NBA returned to play in the NBA at a mean 9.8 months. Among players returning to NBA play, during RTP season 1, mean per game statistics decreased for the following: minutes, points, rebounds, assists, steals, blocks, turnovers and personal fouls - none of these changes reached statistical significance. Player efficiency ratings significantly declined from pre-injury (12.5) to the first RTP season (7.6) (p = 0.05). By RTP season 2, player performance metrics approximated pre-injury levels and were not significantly different. Six studies met inclusion criteria; reported RTP rates ranged from 78-86%. Identified studies similarly found a decline in functional performance after RTP.There is a high rate (89%) of return to NBA play for NBA players undergoing ACLR. After RTP, however, there is a quantitative decline in initial season 1 RTP statistics with a significant decrease in player efficiency rating. By RTP season 2, performance metrics demonstrated an improvement compared to RTP season 1 but did not reach pre-injury functional performance, though performance metrics are not significantly different between pre-injury and RTP season 2.
View details for DOI 10.1080/00913847.2017.1325313
View details for Web of Science ID 000416502100013
View details for PubMedID 28449611
Cancellous Screws Are Biomechanically Superior to Cortical Screws in Metaphyseal Bone
2016; 39 (5): E828-E832
Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synthetic model representing various bone densities. Commercially available, fully threaded, 4.0-mm outer-diameter cortical and cancellous screws were tested in terms of pullout strength and maximum insertion torque in standard-density and osteoporotic cancellous bone models. Pullout strength and maximum insertion torque were both found to be greater for cancellous screws than cortical screws in all synthetic densities tested. The magnitude of difference in pullout strength between cortical and cancellous screws increased with decreasing synthetic bone density. Screw displacement prior to failure and total energy absorbed during pullout strength testing were also significantly greater for cancellous screws in osteoporotic models. Stiffness was greater for cancellous screws in standard and osteoporotic models. Cancellous screws have biomechanical advantages over cortical screws when used in metaphyseal bone, implying the ability to both achieve greater compression and resist displacement at the screw-plate interface. Surgeons should preferentially use cancellous over cortical screws in metaphyseal environments where cortical bone is insufficient for fixation. [Orthopedics.2016; 39(5):e828-e832.].
View details for DOI 10.3928/01477447-20160509-01
View details for Web of Science ID 000393107500003
View details for PubMedID 27172369
Endoscopic-assisted epiphysiodesis: technique and 20-year experience.
Journal of pediatric orthopedics. Part B
2016; 25 (1): 24-30
The aim of the study was to describe the endoscopic-assisted epiphysiodesis technique and review our 20-year experience with it. A retrospective review of 44 patients who underwent proximal tibia and/or distal femur endoscopic-assisted epiphysiodesis was carried out. Only patients who had preoperative and postoperative scanograms with clinical follow-up of at least 6 months were included. The mean length of follow-up was 36.8 months. All patients had radiographic evidence of physeal fusion within 6-12 months from the index procedure. No patient required revision surgery. Endoscopic-assisted epiphysiodesis is safe, effective, and achieves predictable physeal fusion. Advantages over current techniques include reduced radiation exposure and lack of requirement for hardware placement.
View details for DOI 10.1097/BPB.0000000000000230
View details for PubMedID 26462167
Sacral spinous processes: a morphologic classification and biomechanical characterization of strength
2015; 15 (12): 2544-2551
There has been increasing interest in using the lumbosacral spinous processes for fixation as a less invasive alternative to transpedicular instrumentation. Alhough prior studies have described the appearance and biomechanics of lumbar spinous processes, few have evaluated the dimensions, morphology, or strength of the sacral spinous processes.The goals of this study were to characterize the morphology of the S1 spinous process and biomechanical strength of the S1 spinous process when loaded in a cranial direction.This study was performed as both an analysis of radiographic data and biomechanical testing of cadaveric specimens.Lumbosacral spine radiographs and computed tomography scans of 20 patients were evaluated for visibility and morphology of the S1 spinous process. S1 spinous process length, height, and size of the L5-S1 segment were measured. Additionally, 13 cadaveric lumbosacral spinal segments were obtained for biomechanical testing and morphologic analysis. Specimens were loaded at the S1 spinous process in a cranial direction via a strap, simulating resistance to a flexion moment applied across the L5-S1 segment. Peak load to failure, displacement, and mode of failure were recorded.The S1 spinous process was clearly visible on lateral radiographs in only 10% of patients. Mean spinous process length (anterior-posterior) was 11.6 mm while mean spinous process height (cranial-caudal) was 23.1 mm. We identified six different morphologic subtypes of the S1 spinous process: fin, lumbar type, fenestrated, fused, tubercle, and spina bifida occulta. During tension loading of the S1 spinous process in the cephalad direction, mean peak load to failure was 439N, with 92% of specimens failing by fracture through the spinous process.This is the first study evaluating sacral spinous process morphology, visibility, and biomechanical strength for potential instrumentation. Compared with lumbar spinous processes, sacral spinous processes are smaller with more variable morphology but have similar peak load to failure. For ideal visualization of morphology and suitability for interspinous fixation,preoperative three-dimensional imaging may be a valuable tool over plain radiographs.
View details for DOI 10.1016/j.spinee.2015.08.058
View details for Web of Science ID 000366655100049
View details for PubMedID 26343242
- Prevalence of Cancer in Female Plastic Surgeons in the United States Women’s Health Issues 2015; 25 (5): 229-32
The 100 most cited spine articles
EUROPEAN SPINE JOURNAL
2012; 21 (10): 2059–69
Spine-related research has evolved dramatically during the last century. Significant contributions have been made by thousands of authors. A citation rank list has historically been used within a particular field to measure the importance of an article. The purpose of this article is to report on the 100 most cited articles in the field of spine.Science Citation Index Expanded was searched for citations in 27 different journals (as of 30 November 2010) chosen based on the relevance for all cited spine publications. The top 100 most cited articles were identified. Important information such as journal, date, country of origin, author, subspecialty, and level of evidence (for clinical research) were compiled.The top 100 publications ranged from 1,695 to 240 citations. Fifty-three articles were of the lumbar, 17 were of the thoracolumbar, and 15 of the cervical spine. Eighty-one of the articles were clinical and 19 were basic science in nature. Level of evidence varied for the clinical papers, however, was most commonly level IV (34 of 81 articles). Notably, the 1990-1999 decade was the most productive period with 43 of the top 100 articles published during this time.Identification of the most cited articles within the field of spine recognizes some of the most important contributions in the peer-reviewed literature. Current investigators may utilize the aspects of their work to guide and direct future spine-related research.
View details for DOI 10.1007/s00586-012-2303-2
View details for Web of Science ID 000309477000021
View details for PubMedID 22526702
View details for PubMedCentralID PMC3463701
Tau truncation during neurofibrillary tangle evolution in Alzheimer's disease
NEUROBIOLOGY OF AGING
2005; 26 (7): 1015–22
The microtubule-associated protein, tau, is a highly soluble molecule that is nonetheless capable of self-association into filamentous deposits characteristic of a number of neurodegenerative diseases. This state change is thought to be driven by phosphorylation and/or C-terminal truncation events resulting in intracellular inclusions, such as the neurofibrillary tangles (NFTs) in Alzheimer's disease (AD). Previously, we reported the existence of a novel truncation event, cleavage at aspartic acid(421), presumably by a caspase, and also described a monoclonal antibody (Tau-C3) specific for tau cleaved at this site. Here, we report the timing of this cleavage event relative to other antibody-targeted alterations in the tau molecule during the course of NFT evolution in AD. Immunohistochemical studies indicate that cleavage at aspartic acid(421) occurs after formation of the Alz50 epitope but prior to formation of the Tau-66 epitope and truncation at glutamic acid(391) (formation of the MN423 epitope). Thus, creation of the Tau-C3 epitope appears to occur relatively early in the disease state, contemporaneous with the initial Alz50 folding event that heralds the appearance of filamentous tau in NFTs, neuropil threads, and the dystrophic neurites surrounding amyloid plaques.
View details for DOI 10.1016/j.neurobiolaging.2004.09.019
View details for Web of Science ID 000227821000006
View details for PubMedID 15748781
Tau epitope display in progressive supranuclear palsy and corticobasal degeneration
JOURNAL OF NEUROCYTOLOGY
2004; 33 (3): 287–95
Filamentous aggregates of the protein tau are a prominent feature of Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). However, the extent to which the molecular structure of the tau in these aggregates is similar or differs between these diseases is unclear. We approached this question by examining these disorders with a panel of antibodies that represent different structural, conformational, and cleavage-specific tau epitopes. Although each of these antibodies reveals AD pathology, they resolved into three classes with respect to PSP and CBD: AD2 and Tau-46.1 stained the most tau pathology in all cases; Tau-1, 2, 5, and 12 exhibited variable reactivity; and Tau-66 and MN423 did not reveal any tau pathology. In addition, hippocampal neurofibrillary tangles in these cases showed a predominantly PSP/CBD-like, rather than AD-like, staining pattern. These results indicate that the patterns of the tau epitopes represented by this panel that reside in the pathological aggregates of PSP and CBD are similar to each other but distinct from that of AD.
View details for DOI 10.1023/B:NEUR.0000044190.96426.b9
View details for Web of Science ID 000224365600003
View details for PubMedID 15475684