Kirkham Wood

All Publications

• Patient-Level Patterns in Daily Prescribed Opioid Dosage in Single Level Lumbar Fusion are Associated with Postoperative Opioid Dosage and Adverse Events: A Retrospective Analysis of Claims Data. The spine journal : official journal of the North American Spine Society Koltsov, J. C., Sambare, T. D., Kleimeyer, J. P., Alamin, T. F., Wood, K. B., Carragee, E. J., Hu, S. S. 2024

  Abstract

  Patients undergoing lumbar spine surgery have high rates of preoperative opioid use, which is associated with inferior outcomes and higher risks for opioid dependency postoperatively.Determine whether there are identifiable subgroups of patients that follow distinct patterns in pre- and postoperative opioid dosing. Examine how preoperative patterns in opioid dosing relate to postoperative opioid patterns, opioid cessation, and the risk for adverse events.Retrospective analysis of an administrative claims database (MeritiveTM Marketscan® Research Databases 2007-2015).9,768 patients undergoing primary single level lumbar fusion OUTCOME MEASURES: Primary: daily morphine milligram equivalent (MME) opioid dosing calculated from prescriptions dispensed for 1 year before and after surgery; secondary: 90-day all-cause readmission and complications, 90-day acute postoperative pain, 90-day and 1-year reoperation, surgical costs, length of stay, and discharge disposition.Distinct patient subgroups defined by patterns of daily MME pre- and postoperatively were identified via group-based trajectory modeling. Associations between these groups and outcomes were assessed with multivariable logistic regression with risk adjustment for patient and surgical factors.Among primary single level lumbar fusion patients, 59.5% filled an opioid prescription in the 3 months preceding surgery, whereas 40.5% were opioid naïve (Naïve). Five distinct subgroups of daily MME were identified among those filling opioids preoperatively: (1) Naïve to 3m (21.2% of patients): no opioids until 3 months preoperatively, escalating to 15 MME/day; (2) Low to 3m (11.4%): very low or as needed dose until 3 months preoperatively, escalating to 15 MME/day; (3) 6m Rise (6.9%): no opioids until 6 months preoperatively, escalating to >30 MME/day; (4) Medium (9.8%): increased linearly from 10 to 25 MME/day across the year before surgery; (5) High (10.0%): increased linearly from 60 to >80 MME/day across the year before surgery. These five preoperative opioid groups were related to postoperative opioids filled in a dose-response manner. The two preoperative patient groups with chronic Medium to High-dose opioid dosing were associated with increased adverse events, including all-cause readmission, reoperation, and pneumonia, whereas a low baseline group with a large, earlier preoperative rise in opioid dosing (6m Rise) had increased encounters for acute postoperative pain. Postoperatively, only 9.5% of patients did not fill an opioid prescription. Five distinct postoperative subgroups were identified based on their patterns in daily MME: Two groups ceased filling opioids within the year following surgery (33.6% of patients), and three groups declined in opioid dosage following surgery but plateaued at low (0-5 MME/day, 29.1%), medium (10-15 MME/day, 12.0%) or high (70-75 MME/day), 13.1%) doses by 1 year. Patients within the higher preoperative opioid groups were more likely to belong to the postoperative groups that were unable to cease filling opioids.Identification of a patient's pre-operative time trend in daily opioid use may provide significant prognostic value and help guide pain management and risk reduction efforts.III.

  View details for DOI 10.1016/j.spinee.2024.03.011

  View details for PubMedID 38521464

• Reliability of semi-automated spinal measurement software. Spine deformity Follett, M., Karamian, B., Liu, N., Alamin, T., Wood, K. B. 2024

  Abstract

  PURPOSE: In the treatment of patients with adult spinal deformity, analysis of spinopelvic balance is essential in clinical assessment and surgical planning. There is currently no gold standard for measurement, whether done by hand or with digital software. New semi-automated software exists that purports to increase efficiency, but its reliability is unknown in the literature.METHODS: Full spine X-rays were retrospectively reviewed from 25 adult patients seen between 2014 and 2017. Patients were included if they had>5cm of sagittal imbalance and radiographs of sufficient quality to perform balance measurements, without prior surgical spinal fusion and/or instrumentation. Spinopelvic parameters were measured in two radiographic programs: one with basic, non-spine-specific measurement tools (eUnity, Client Outlook, Waterloo, Canada); and a second with spine-specific semi-automated measurement tools (Sectra, Sectra AB, Linkoping, Sweden). Balance parameters included SVA, PI, PT, and LL. Data were compared by examining inter-rater and inter-program reliability using interclass correlation coefficient (ICC).RESULTS: The subjects' mean age was 67.9±13.8years old, and 32% were male. The inter-program reliability was strong, with ICC values greater than 0.91 for each parameter. Similarly, there was strong inter-observer reliability with ICC values greater than 0.88. These results persisted on delayed repeat measurement (p<0.001 for all measurements).CONCLUSION: There is excellent inter-observer and inter-program reliability between the basic PACS and semi-automated programs. These data demonstrate that the purported efficiency of semi-automated measurement programs does not come at the cost of measurement reliability.

  View details for DOI 10.1007/s43390-023-00795-7

  View details for PubMedID 38214827

• Polymethyl methacrylate augmentation and proximal junctional kyphosis in adult spinal deformity patients. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society Bartolozzi, A. R., Oquendo, Y. A., Koltsov, J. C., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2023

  Abstract

  Proximal junctional kyphosis (PJK) is a complication following surgery for adult spinal deformity (ASD) possibly ameliorated by polymethyl methacrylate (PMMA) vertebroplasty of the upper instrumented vertebrae (UIV). This study quantifies PJK following surgical correction bridging the thoracolumbar junction ± PMMA vertebroplasty.ASD patients from 2013 to 2020 were retrospectively reviewed and included with immediate postoperative radiographs and at least one follow-up radiograph. PMMA vertebroplasty at the UIV and UIV + 1 was performed at the surgeons' discretion.Of 102 patients, 56% received PMMA. PMMA patients were older (70 ± 8 vs. 66 ± 10, p = 0.021), more often female (89.3% vs. 68.2%, p = 0.005), and had more osteoporosis (26.8% vs. 9.1%, p = 0.013). 55.4% of PMMA patients developed PJK compared to 38.6% of controls (p = 0.097), and the rate of PJK development was not different between groups in univariate survival models. There was no difference in PJF (p > 0.084). Reoperation rates were 7.1% in PMMA versus 11.4% in controls (p = 0.501). In multivariable models, PJK development was not associated with the use of PMMA vertebroplasty (HR 0.77, 95% CI 0.38-1.60, p = 0.470), either when considered overall in the cohort or specifically in those with poor bone quality. PJK was significantly predicted by poor bone quality irrespective of PMMA use (HR 3.81, p < 0.001).In thoracolumbar fusions for adult spinal deformity, PMMA vertebroplasty was not associated with reduced PJK development, which was most highly associated with poor bone quality. Preoperative screening and management for osteoporosis is critical in achieving an optimal outcome for these complex operations.4, retrospective non-randomized case review.

  View details for DOI 10.1007/s00586-023-07966-0

  View details for PubMedID 37812256

  View details for PubMedCentralID 3508213

• Patient-Level Payment Patterns Prior to Single Level Lumbar Decompression are Associated with Resource Utilization, Postoperative Payments, and Adverse Events. The spine journal : official journal of the North American Spine Society Koltsov, J. C., Sambare, T. D., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2022

  Abstract

  BACKGROUND: Understanding patient-specific trends in costs and healthcare resource utilization (HCRU) surrounding lumbar spine surgery is critically needed to better inform surgical decision making and the development of targeted interventions.PURPOSE: 1) Identify subgroups of patients following distinct patterns in direct healthcare payments pre- and postoperatively, 2) determine whether these patterns are associated with patient and surgical factors, and 3) examine whether preoperative payment patterns are related to postoperative payments, healthcare resource utilization (HCRU), and adverse events.STUDY DESIGN/SETTING: Retrospective analysis of an administrative claims database (IBM Marketscan Research Databases 2007-2015).PATIENT SAMPLE: Adults undergoing primary single-level decompression surgery for lumbar stenosis (n=12,394).OUTCOME MEASURES: Direct healthcare payments, HCRU payments (15 categories), 90-day complications and all-cause readmission, 2-year reoperation METHODS: Group-based trajectory modeling is an application of finite mixture modeling that is able to identify meaningful subgroups within a population that follow distinct developmental trajectories over time. We used this technique to identify subgroups of patients following distinct profiles in preoperative direct healthcare payments. A separate analysis was performed to identify distinct profiles in payments postoperatively. Patient and surgical factors associated with these payment profiles were assessed with multinomial logistic regression, and associations with adverse events were assessed with risk-adjusted multivariable logistic regression.RESULTS: We identified 4 preoperative patient payment subgroups following distinct profiles in payments: Pre-Low (5.8% of patients), Pre-Early-Rising (4.8%), Pre-Medium (26.1%), and Pre-High (63.3%). Postoperatively, 3 patient subgroups were identified: Post-Low (8.9%), Post-Medium (29.6%), and Post-High (61.4%). Patients following the higher-cost pre- and postoperative payment profiles were older, more likely female, and had a greater physical and mental comorbidity burden. With each successively higher preoperative payment profile, patients were increasingly likely to have high postoperative payments, use more HCRU (particularly high-cost services such as inpatient admissions, ER, and SNF/IRF care), and experience postoperative adverse events. Following risk adjustment for patient and surgical factors, patients following the Pre-High payment profile had 209.5 (95% CI: 144.2, 309.7; p<0.001) fold greater odds for following the Post-High payment profile, 1.8 (1.3, 2.5; p=0.003) fold greater odds for 90-day complications, and 1.7 (1.2, 2.6; p=0.035) fold greater odds for 2-year reoperation relative to patients following the Pre-Low payment profile.CONCLUSIONS: There are identifiable subgroups of patients who follow distinct profiles in direct healthcare payments surrounding lumbar decompression surgery. These payment profiles are related to patient age, sex, and physical and mental comorbidities. Notably, preoperative payment profiles may provide prognostic value, as they are associated with postoperative costs, HCRU, and adverse events.LEVEL OF EVIDENCE: III.

  View details for DOI 10.1016/j.spinee.2022.10.002

  View details for PubMedID 36241040

• Catastrophic acute failure of pelvic fixation in adult spinal deformity requiring revision surgery: a multicenter review of incidence, failure mechanisms, and risk factors. Journal of neurosurgery. Spine Martin, C. T., Holton, K. J., Elder, B. D., Fogelson, J. L., Mikula, A. L., Kleck, C. J., Calabrese, D., Burger, E. L., Ou-Yang, D., Patel, V. V., Kim, H. J., Lovecchio, F., Hu, S. S., Wood, K. B., Harper, R., Yoon, S. T., Ananthakrishnan, D., Michael, K. W., Schell, A. J., Lieberman, I. H., Kisinde, S., DeWald, C. J., Nolte, M. T., Colman, M. W., Phillips, F. M., Gelb, D. E., Bruckner, J., Ross, L. B., Johnson, J. P., Kim, T. T., Anand, N., Cheng, J. S., Plummer, Z., Park, P., Oppenlander, M. E., Sembrano, J. N., Jones, K. E., Polly, D. W. 2022: 1-9

  Abstract

  There are few prior reports of acute pelvic instrumentation failure in spinal deformity surgery. The objective of this study was to determine if a previously identified mechanism and rate of pelvic fixation failure were present across multiple institutions, and to determine risk factors for these types of failures.Thirteen academic medical centers performed a retrospective review of 18 months of consecutive adult spinal fusions extending 3 or more levels, which included new pelvic screws at the time of surgery. Acute pelvic fixation failure was defined as occurring within 6 months of the index surgery and requiring surgical revision.Failure occurred in 37 (5%) of 779 cases and consisted of either slippage of the rods or displacement of the set screws from the screw tulip head (17 cases), screw shaft fracture (9 cases), screw loosening (9 cases), and/or resultant kyphotic fracture of the sacrum (6 cases). Revision strategies involved new pelvic fixation and/or multiple rod constructs. Six patients (16%) who underwent revision with fewer than 4 rods to the pelvis sustained a second acute failure, but no secondary failures occurred when at least 4 rods were used. In the univariate analysis, the magnitude of surgical correction was higher in the failure cohort (higher preoperative T1-pelvic angle [T1PA], presence of a 3-column osteotomy; p < 0.05). Uncorrected postoperative deformity increased failure risk (pelvic incidence-lumbar lordosis mismatch > 10°, higher postoperative T1PA; p < 0.05). Use of pelvic screws less than 8.5 mm in diameter also increased the likelihood of failure (p < 0.05). In the multivariate analysis, a larger preoperative global deformity as measured by T1PA was associated with failure, male patients were more likely to experience failure than female patients, and there was a strong association with implant manufacturer (p < 0.05). Anterior column support with an L5-S1 interbody fusion was protective against failure (p < 0.05).Acute catastrophic failures involved large-magnitude surgical corrections and likely resulted from high mechanical strain on the pelvic instrumentation. Patients with large corrections may benefit from anterior structural support placed at the most caudal motion segment and multiple rods connecting to more than 2 pelvic fixation points. If failure occurs, salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.

  View details for DOI 10.3171/2022.6.SPINE211559

  View details for PubMedID 36057123

• Healthcare Resource Utilization and Costs Two Years Pre and Post Lumbar Spine Surgery for Stenosis: A National Claims Cohort Study of 22,182 Cases. The spine journal : official journal of the North American Spine Society Koltsov, J. C., Sambare, T. D., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2022

  Abstract

  BACKGROUND: Improved understanding of the pre and postoperative trends in costs and healthcare resource utilization (HCRU) is needed to better inform patient expectations and aid in the development of strategies to minimize the significant healthcare burden associated with lumbar spine surgery.PURPOSE: Examine the time course of costs and HCRU in the two years preceding and following elective lumbar spine surgery for stenosis in a large national claims cohort STUDY DESIGN/SETTING: Retrospective analysis of an administrative claims database (IBM Marketscan Research Databases 2007-2015) PATIENT SAMPLE: Adult patients undergoing elective primary single-level lumbar surgery for stenosis with at least 2 years of continuous health plan enrollment pre- and postoperatively OUTCOME MEASURES: Functional measures, including monthly rates of HCRU (15 categories), monthly gross covered payments (including payments made by the health plan and deductibles and coinsurance paid by the patient) overall, by HCRU category, and by spine versus non-spine-related METHODS: All available patients were utilized for analysis of HCRU. For analysis of payments, only patients on non-capitated health plans providing accurate financial information were analyzed. Payments were converted to 2015 United States dollars using the medical care component of the consumer price index. Trends in payments and HCRU were plotted on a monthly basis pre- and post-surgery and assessed with regression models. Relationships with demographics, surgical factors, and comorbidities were assessed with multivariable repeated measures generalized estimating equations.RESULTS: Median monthly healthcare payments 2 years prior to surgery were $275 ($22, $868). Baseline HCRU at 2 years preoperatively was stable or only gradually rising (office visits, prescription drug use), but began an increasingly steep rise in many categories 6 to 12 months prior to surgery. Monthly payments began an increasingly steep rise 6 months prior to surgery, reaching a peak of $1,402 ($634, $2,827) in the month prior to surgery. This was driven by an increase in radiology, office visits, PT, injections, prescription medications, ER encounters, and inpatient admissions. Payments dropped dramatically immediately following surgery. Over the remainder of the 2 years, the median total payments declined only slightly, as a continued decline in spine-related payments was offset by gradually increased non-spine related payments as patients aged. By 2 years postoperatively, the percentage of patients using PT and injections returned to within 1% of the baseline levels observed 2 years preoperatively; however, spine-related prescription medication use remained elevated, as did other categories of HCRU (radiology, office visits, lab/diagnostic services, and also rare events such as inpatient admissions, ER encounters, and SNF/IRF). Patients with a fusion component to their surgeries had higher payments and HCRU preoperatively, and this did not resolve postoperatively. Variations in payments and HCRU were also evident among plan types, with patients on comprehensive medical plans-predominantly employer-sponsored supplemental Medicare coverage-utilizing more inpatient, ER, and inpatient rehabilitation & skilled nursing facilities. Patients on high-deductible plans had fewer payments and HCRU across all categories; however, we are unable to distinguish whether this is because they used fewer of these services or if they were paying for these services out of pocket without submitting to the payer. By 2 years postoperatively, 51% of patients had no spine-related monthly payments, while 33% had higher and 16% had lower monthly payments relative to 2 years preoperatively.CONCLUSIONS: This is the first study to characterize time trends in direct healthcare payments and HCRU over an extended period preceding and following spine surgery. Differences among plan types potentially highlight disparities in access to care and plan-related financial mediators of patients' healthcare resource utilization.LEVEL OF EVIDENCE: III.

  View details for DOI 10.1016/j.spinee.2022.01.020

  View details for PubMedID 35123048

• Bacteria in Surgical Smoke: A Self-Controlled Lab Study Using Porcine Spinal Tissues. Spine Zhu, Z., Liu, N., Xia, W., Liu, H., Wood, K. B., Wang, K. 2021

  Abstract

  STUDY DESIGN: A lab study performed in a self-controlled fashion.OBJECTIVE: To examine whether "surgical smoke" generated by using the electrocautery on porcine spinal tissues could contain viable bacteria.SUMMARY OF BACKGROUND DATA: The year 2020 has seen a surge in legislation regarding surgical smoke evacuation in the operating room across the United States. Surgical smoke contains numerous toxic and carcinogenic substances, which spine surgeons and operating room staff are regularly exposed to. While the smoke's chemical toxicity has been extensively studied, little is known about its biohazard level.METHODS: The electrocautery was used to "operate on" 20 segments of porcine spinal tissues on a clean bench. In each operation, the generated smoke was captured with a swab, which was positioned above the surgical site and within the smoke, to obtain bacteria cultures. Two other swabs -a tissue swab (swabbing the porcine tissue itself) and a blank swab (swabbing an empty sterile bowl)- were collected as controls. The culture results were compared among the three groups. An additional experiment was conducted to see whether using a mask can reduce the "infection rate" of the swab.RESULTS: While all blank swabs tested negative, 95% (19/20) of the smoke swabs tested positive, with a total of nine bacteria species identified. The most prevalent species observed in the smoke swabs included Serratia liquefaciens, Lactococcus garvieae, and Hafnia alvei, etc. Among the positive smoke swabs, 84% (16/19) had one or more bacteria species that were consistent with the cultures of their corresponding tissue swabs. Using a surgical or N95 mask reduced the "infection rate" of the swab.CONCLUSIONS: "Surgical smoke" generated by electrocauterization of porcine spinal tissues contains viable bacteria. Further research in actual spine surgery is needed next.Level of Evidence: N/A.

  View details for DOI 10.1097/BRS.0000000000004079

  View details for PubMedID 33907080

• Rod-Screw Constructs Composed of Dissimilar Metals Do Not Affect Complication Rates in Posterior Fusion Surgery Performed for Adult Spinal Deformity. Clinical spine surgery Denduluri, S. K., Koltsov, J. C., Ziino, C. n., Segovia, N. n., McMains, C. n., Falakassa, J. n., Ratliff, J. n., Wood, K. B., Alamin, T. n., Cheng, I. n., Hu, S. S. 2021; 34 (2): E121–E125

  Abstract

  This was a retrospective cohort study.The objective of this study was to compare implant-related complications between mixed-metal and same-metal rod-screw constructs in patients who underwent posterior fusion for adult spinal deformity.Contact between dissimilar metals is discouraged due to potential for galvanic corrosion, increasing the risk for metal toxicity, infection, and implant failure. In spine surgery, titanium (Ti) screws are most commonly used, but Ti rods are notch sensitive and likely more susceptible to fracture after contouring for deformity constructs. Cobalt chrome (CC) and stainless steel (SS) rods may be suitable alternatives. No studies have yet evaluated implant-related complications among mixed-metal constructs (SS or CC rods with Ti screws).Adults with spinal deformity who underwent at least 5-level thoracic and/or lumbar posterior fusion or 3-column osteotomy between January 2013 and May 2015 were reviewed, excluding neuromuscular deformity, tumor, acute trauma or infection. Implant-related complications included pseudarthrosis, proximal junctional kyphosis, hardware failure (rod fracture, screw pullout or haloing), symptomatic hardware, and infection.A total of 61 cases met inclusion criteria: 24 patients received Ti rods with Ti screws (Ti-Ti, 39%), 31 SS rods (SS-Ti, 51%), and 6 CC rods (CC-Ti, 9.8%). Median follow-up was 37-42 months for all groups. Because of the limited number of cases, the CC-Ti group was not included in statistical analyses. There were no differences between Ti-Ti and SS-Ti groups with regard to age, body mass index, or smokers. Implant-related complications did not differ between the Ti-Ti and SS-Ti groups (P=0.080). Among the Ti-Ti group, there were 15 implant-related complications (63%). In the SS-Ti group, there were 12 implant-related complications (39%). There were 3 implant-related complications in the CC-Ti group (50%).We found no evidence that combining Ti screws with SS rods increases the risk for implant-related complications.

  View details for DOI 10.1097/BSD.0000000000001058

  View details for PubMedID 33633069

• Rod-Screw Constructs Composed of Dissimilar Metals Do Not Affect Complication Rates in Posterior Fusion Surgery Performed for Adult Spinal Deformity. Clinical spine surgery Denduluri, S. K., Koltsov, J. C., Ziino, C., Segovia, N., McMains, C., Falakassa, J., Ratliff, J., Wood, K. B., Alamin, T., Cheng, I., Hu, S. S. 2020

  Abstract

  STUDY DESIGN: This was a retrospective cohort study.OBJECTIVE: The objective of this study was to compare implant-related complications between mixed-metal and same-metal rod-screw constructs in patients who underwent posterior fusion for adult spinal deformity.SUMMARY OF BACKGROUND DATA: Contact between dissimilar metals is discouraged due to potential for galvanic corrosion, increasing the risk for metal toxicity, infection, and implant failure. In spine surgery, titanium (Ti) screws are most commonly used, but Ti rods are notch sensitive and likely more susceptible to fracture after contouring for deformity constructs. Cobalt chrome (CC) and stainless steel (SS) rods may be suitable alternatives. No studies have yet evaluated implant-related complications among mixed-metal constructs (SS or CC rods with Ti screws).METHODS: Adults with spinal deformity who underwent at least 5-level thoracic and/or lumbar posterior fusion or 3-column osteotomy between January 2013 and May 2015 were reviewed, excluding neuromuscular deformity, tumor, acute trauma or infection. Implant-related complications included pseudarthrosis, proximal junctional kyphosis, hardware failure (rod fracture, screw pullout or haloing), symptomatic hardware, and infection.RESULTS: A total of 61 cases met inclusion criteria: 24 patients received Ti rods with Ti screws (Ti-Ti, 39%), 31 SS rods (SS-Ti, 51%), and 6 CC rods (CC-Ti, 9.8%). Median follow-up was 37-42 months for all groups. Because of the limited number of cases, the CC-Ti group was not included in statistical analyses. There were no differences between Ti-Ti and SS-Ti groups with regard to age, body mass index, or smokers. Implant-related complications did not differ between the Ti-Ti and SS-Ti groups (P=0.080). Among the Ti-Ti group, there were 15 implant-related complications (63%). In the SS-Ti group, there were 12 implant-related complications (39%). There were 3 implant-related complications in the CC-Ti group (50%).CONCLUSION: We found no evidence that combining Ti screws with SS rods increases the risk for implant-related complications.

  View details for DOI 10.1097/BSD.0000000000001058

  View details for PubMedID 32925188

• Preoperative epidural steroid injections are not associated with increased rates of infection and dural tear in lumbar spine surgery. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society Koltsov, J. C., Smuck, M. W., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2020

  Abstract

  PURPOSE: The study objectives were to use a large national claims data resource to examine rates of preoperative epidural steroid injections (ESI) in lumbar spine surgery and determine whether preoperative ESI or the timing of preoperative ESI is associated with rates of postoperative complications and reoperations.METHODS: A retrospective longitudinal analysis of patients undergoing lumbar spine surgery for disc herniation and/or spinal stenosis was undertaken using the MarketScan databases from 2007-2015. Propensity-score matched cohorts were constructed to compare rates of complications and reoperations in patients with and without preoperative ESI.RESULTS: Within the year prior to surgery, 120,898 (46.4%) patients had a lumber ESI. The median time between ESI and surgery was 10weeks. 23.1% of patients having preoperative ESI had more than one level injected, and 66.5% had more than one preoperative ESI treatment. Patients with chronic pain were considerably more likely to have an ESI prior to their surgery [OR 1.62 (1.54, 1.69), p<0.001]. Patients having preoperative ESI within in close proximity to surgery did not have increased rates of infection, dural tear, neurological complications, or surgical complications; however, they did experience higher rates of reoperations and readmissions than those with no preoperative ESI (p<0.001).CONCLUSION: Half of patients undergoing lumbar spine surgery for stenosis and/or herniation had a preoperative ESI. These were not associated with an increased risk for postoperative complications, even when the ESI was given in close proximity to surgery. Patients with preoperative ESI were more likely to have readmissions and reoperations following surgery.

  View details for DOI 10.1007/s00586-020-06566-6

  View details for PubMedID 32789696

• Cervical Epidural Steroid Injections: Incidence and Determinants of Subsequent Surgery. The spine journal : official journal of the North American Spine Society Kleimeyer, J. P., Koltsov, J. C., Smuck, M. W., Wood, K. B., Cheng, I., Hu, S. S. 2020

  Abstract

  BACKGROUND CONTEXT: Cervical epidural steroid injections (CESIs) are sometimes used in the management of cervical radicular pain in order to delay or avoid surgery. However, the rate and determinants of surgery following CESIs remain uncertain.PURPOSE: This study sought to determine: 1) the proportion of patients having surgery following CESI, and 2) the timing of and factors associated with subsequent surgery.STUDY DESIGN: Retrospective analysis of a large, national administrative claims database.PATIENT SAMPLE: The study included 192,777 CESI patients (age 50.9±11.3 years, 55.2% female) who underwent CESI for imaging-based diagnoses of cervical disc herniation or stenosis, a clinical diagnosis of radiculopathy, or a combination thereof.OUTCOME MEASURES: The primary outcome was the time from index CESI to surgery.METHODS: Inclusion criteria were CESI for cervical disc herniation, stenosis, or radiculopathy, age ≥18, and active enrollment for 1 year prior to CESI to screen for exclusions. Patients were followed until they underwent cervical surgery, or their enrollment lapsed. Rates of surgery were assessed with Kaplan-Meier survival curves and 99% confidence intervals. Factors associated with subsequent surgery were assessed with multivariable Cox proportional hazard models.RESULTS: Within 6 months of CESI, 11.2% of patients underwent surgery, increasing to 14.5% by 1 year and 22.3% by 5 years. Male patients and those aged 35-54 had an increased likelihood of subsequent surgery. Patients with radiculopathy were less likely to undergo surgery following CESI than those with stenosis or herniation, while patients with multiple diagnoses were more likely. Patients with comorbidities including CHF, other cardiac comorbidities or chronic pain were less likely to undergo surgery, as were patients in the northeast US region. Some 33.5% of patients underwent >1 CESI, with 84.6% of these occurring within 1 year. Additional injections were associated with reduced rates of subsequent surgery.CONCLUSIONS: Following CESI, over one in five patients underwent surgery within 5 years. Multiple patient-specific risk factors for subsequent surgery were identified, and patients undergoing repeated injections were at lower risk. Determining which patients may progress to surgery can be used to improve resource utilization and to inform shared decision-making.

  View details for DOI 10.1016/j.spinee.2020.06.012

  View details for PubMedID 32565316

• Knee or Spine Surgery First? A Survey of Treatment Order for Patients With Concurrent Degenerative Knee and Lumbar Spinal Disorders. The Journal of arthroplasty Goodman, S. B., Lachiewicz, P. F., Liu, N. n., Wood, K. B. 2020

  Abstract

  Total knee arthroplasty (TKA) and lumbar spine surgery have been reported to affect the outcomes of each other. There is insufficient evidence to guide the choice of treatment order for patients with both disorders that are equally symptomatic.Five clinical scenarios of concurrent, advanced, degenerative knee and lumbar spinal disorders were designed to survey surgeons' choices of treatment order and rationale. The spinal disorder was consistently degenerative lumbar spinal stenosis, but the knee conditions varied to include (1) osteoarthritis (OA) with varus deformity, (2) OA with valgus deformity, (3) rheumatoid arthritis with a severe flexion contracture, (4) OA without deformity, and (5) bilateral OA with windswept deformities. The survey was distributed to selected clinical members of the Knee Society and Scoliosis Research Society in North America. The surgeons' choices were compared among the 5 scenarios, and their comments were analyzed using text-mining.Responses were received from 42 of 74 (57%) knee arthroplasty surgeons and 55 of 100 (55%) spine surgeons. The percentages of knee arthroplasty surgeons recommending "TKA first" differed significantly among scenarios: 29%, 79%, 55%, 7%, and 81% for scenarios 1 through 5, respectively (P < .001). A similar pattern was noted for the spine surgeons.For patients with concurrent degenerative knee and lumbar spinal disorders, the severity and type of knee deformity influenced the preference of treatment order in both specialties. Severe valgus deformity and windswept deformities of the knee would drive the decision toward "TKA first."

  View details for DOI 10.1016/j.arth.2020.03.018

  View details for PubMedID 32247672

• Lateral femoral sliding osteotomy in total knee arthroplasty with valgus deformity greater than twenty degrees INTERNATIONAL ORTHOPAEDICS Li, F., Liu, N., Li, Z., Wood, K. B., Tian, H. 2019; 43 (11): 2511–17

  View details for DOI 10.1007/s00264-019-04295-0

  View details for Web of Science ID 000495791400012

• Timing of Lumbar Spinal Fusion Affects Total Hip Arthroplasty Outcomes. Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews Bala, A., Chona, D. V., Amanatullah, D. F., Hu, S. S., Wood, K. B., Alamin, T. F., Cheng, I. 2019; 3 (11): e00133

  Abstract

  Many patients are affected by concurrent disease of the hip and spine, undergoing both total hip arthroplasty (THA) and lumbar spinal fusion (LSF). Recent literature demonstrates increased prosthetic dislocation rates in patients with THA done after LSF. Evidence is lacking on which surgery to do first to minimize complications. The purpose of this study was to evaluate the effect of timing between the two procedures on postoperative outcomes.Methods: We queried the Medicare standard analytics files between 2005 and 2014. Four groups were identified and matched by age and sex: THA with previous LSF, LSF with previous THA, THA with spine pathology without fusion, and THA without spine pathology. Revision THA or LSF and bilateral THA were excluded. Comorbidities and Charlson Comorbidity Index were identified. Postoperative complications at 90 days and 2 years were calculated after the most recent surgery. Four-way chi-squared and standard descriptive statistics were calculated.Results: Thirteen thousand one hundred two patients had THA after LSF, 10,482 patients had LSF after THA, 104,820 had THA with spine pathology, and 492,654 had THA without spine pathology. There was no difference in the Charlson Comorbidity Index score between the THA after LSF and LSF after THA groups. There was a statistically significant difference in THA dislocation rate, with LSF after THA at 1.7%, THA without spine pathology at 2.3%, THA with spine pathology at 3.3%, and THA after LSF at 4.6%. There was a statistically significant difference in THA revision rate, with THA without spine pathology at 3.3%, LSF after THA at 3.7%, THA with spine pathology at 4.2%, and THA after LSF at 5.7%.Conclusion: LSF after THA is associated with a reduced dislocation rate compared with THA after LSF. Reasons may include decreasing pelvic mobility in a stable, well-healed THA or early postoperative spine precautions after LSF restricting positions of dislocation.

  View details for DOI 10.5435/JAAOSGlobal-D-19-00133

  View details for PubMedID 31875203

• The Utility of Local Smoke Evacuation in Reducing Surgical Smoke Exposure in Spine Surgery: A Prospective Self-Controlled Study. The spine journal : official journal of the North American Spine Society Liu, N., Filipp, N., Wood, K. B. 2019

  Abstract

  BACKGROUND CONTEXT: Exposure to surgical smoke remains a potential occupational health concern to spine operating room personnel. Using a smoke evacuator (local exhaust ventilation) is currently regarded as a primary means of protection, yet few studies have evaluated its utility in actual surgeries.OBJECTIVE: To examine the utility of two common types of local smoke evacuators, a para incisional evacuator and a smoke evacuation pencil, in reducing surgical smoke exposure in spine surgery.STUDY DESIGN: A prospective self-controlled study.PATIENT SAMPLE: After the pre-estimation of sample size, 51 consecutive spine surgeries (25 and 26 patients using the para incisional smoke evacuator and the smoke evacuation pencil, respectively) were enrolled between February 2018 and March 2019.OUTCOME MEASURES: Two outcome measures were used to evaluate the level of surgical smoke exposure, which was defined as the concentration of ultrafine smoke particles in the air (number of particles per cm3, ppc) around the operating table: (a) the average smoke level was the arithmetic mean of all measurements recorded during the surgery; and (b) the peak smoke level was the highest measurement recorded.METHODS: Consecutive surgeries that involved bilateral symmetrical surgical exposure of the spine via a posterior midline incision were evaluated. Cauterized smoke was evacuated by two smoke evacuators: a "para incisional evacuator," which used a flat broad suction pad positioned immediately adjacent to the incision (25 patients), and a "surgical smoke evacuation pencil" which is an incorporated part of the electrocautery (26 patients). The level of smoke exposure was measured separately when surgically exposing the two sides of the spine: starting with one side (determined randomly) with the smoke evacuator being turned on and, then, the other side with the smoke evacuator off. The results were compared between the two sides.RESULTS: The para incisional smoke evacuator significantly reduced the average smoke level by an average of 59.7% [287 (IQR: 126, 526) vs. 1177 (IQR: 395, 2702), P<0.001]. The surgical smoke evacuation pencil also reduced the average smoke level by an average of 44.1% [917 (IQR: 448, 1936) vs. 1605 (IQR: 775, 4280), P<0.001]. Both evacuators significantly reduced peak smoke levels as well.CONCLUSIONS: This study provides evidence supporting the utility of local smoke evacuation in reducing surgical smoke exposure in spine surgery. Such technology may help to improve the occupational health protection for spine operating room workers.

  View details for DOI 10.1016/j.spinee.2019.09.014

  View details for PubMedID 31542472

• Short-Term Outcomes of Staged Versus Same-Day Surgery for Adult Spinal Deformity Correction. Spine deformity Arzeno, A. H., Koltsov, J., Alamin, T. F., Cheng, I., Wood, K. B., Hu, S. S. 2019; 7 (5): 796-804

  Abstract

  Retrospective cohort study.Assess differences between staged (≤3 days) and same-day surgery in perioperative factors, radiographic measures, and complications. Surgical adult spinal deformity correction may require combined anterior and posterior approaches. To modulate risk, some surgeons perform surgery that is expected to be longer and/or more complex in two stages. Prior studies comparing staged (≥7 days) and same-day surgery demonstrated mixed results and none have examined results with shorter staging intervals.Retrospective review of adults undergoing combined anterior/posterior approaches for spinal deformity over a 3-year period at a single institution (n=92). Univariate differences between staged and same-day surgery were assessed with chi-squared, Fisher exact, and Mann-Whitney U tests. Generalized estimating equations assessed whether differences in perioperative outcomes between groups remained after adjusting for differences in demographic and surgical characteristics.In univariate analyses, staged surgery was associated with a length of stay (LOS) 3 days longer than same-day surgery (9.2 vs. 6.3 days, p < .001), and greater operative time, blood loss, transfusion requirement, and days in intensive care unit (p < .001 for each). Staged surgery had a higher rate of thrombotic events (p = .011) but did not differ in readmission rates or other complications. Radiographically, improvements in Cobb angle (average 13° vs. 17°, p = .028), lumbar lordosis (average 14° vs. 23°, p = .019), and PI-LL mismatch (average 10° vs. 2° p = .018) were greater for staged surgery, likely related to more extensive use of osteotomies in the staged group. After risk adjustment, taking into account the procedural specifics including longer fusion constructs and greater number of osteotomies, LOS no longer differed between staged and same-day surgery; however, the total operative time was 98 minutes longer for staged surgery (p < .001). Differences in blood loss between groups was accounted for by differences in operative time and patient and surgical characteristics.Although univariate analysis of our results were in accordance with previously published works, multivariate analysis allowing individual case risk adjustment revealed that LOS was not significantly increased in the staged group as reported in previous studies. There was no difference in infection rates as previously described but an increase in thrombotic events was observed.Level III.

  View details for DOI 10.1016/j.jspd.2018.12.008

  View details for PubMedID 31975196

• Short-Term Outcomes of Staged Versus Same-Day Surgery for Adult Spinal Deformity Correction. Spine deformity Arzeno, A. H., Koltsov, J., Alamin, T. F., Cheng, I., Wood, K. B., Hu, S. S. 2019; 7 (5): 796

  Abstract

  STUDY DESIGN: Retrospective cohort study.OBJECTIVES: Assess differences between staged (≤3 days) and same-day surgery in perioperative factors, radiographic measures, and complications.SUMMARY OF BACKGROUND DATA: Surgical adult spinal deformity correction may require combined anterior and posterior approaches. To modulate risk, some surgeons perform surgery that is expected to be longer and/or more complex in two stages. Prior studies comparing staged (≥7 days) and same-day surgery demonstrated mixed results and none have examined results with shorter staging intervals.METHODS: Retrospective review of adults undergoing combined anterior/posterior approaches for spinal deformity over a 3-year period at a single institution (n=92). Univariate differences between staged and same-day surgery were assessed with chi-squared, Fisher exact, and Mann-Whitney U tests. Generalized estimating equations assessed whether differences in perioperative outcomes between groups remained after adjusting for differences in demographic and surgical characteristics.RESULTS: In univariate analyses, staged surgery was associated with a length of stay (LOS) 3 days longer than same-day surgery (9.2 vs. 6.3 days, p < .001), and greater operative time, blood loss, transfusion requirement, and days in intensive care unit (p < .001 for each). Staged surgery had a higher rate of thrombotic events (p = .011) but did not differ in readmission rates or other complications. Radiographically, improvements in Cobb angle (average 13° vs. 17°, p = .028), lumbar lordosis (average 14° vs. 23°, p = .019), and PI-LL mismatch (average 10° vs. 2° p = .018) were greater for staged surgery, likely related to more extensive use of osteotomies in the staged group. After risk adjustment, taking into account the procedural specifics including longer fusion constructs and greater number of osteotomies, LOS no longer differed between staged and same-day surgery; however, the total operative time was 98 minutes longer for staged surgery (p < .001). Differences in blood loss between groups was accounted for by differences in operative time and patient and surgical characteristics.CONCLUSIONS: Although univariate analysis of our results were in accordance with previously published works, multivariate analysis allowing individual case risk adjustment revealed that LOS was not significantly increased in the staged group as reported in previous studies. There was no difference in infection rates as previously described but an increase in thrombotic events was observed.LEVEL OF EVIDENCE: Level III.

  View details for DOI 10.1016/j.jspd.2018.12.008

  View details for PubMedID 31495481

• Reliability of radiological measurements of type 2 odontoid fracture SPINE JOURNAL Karamian, B. A., Liu, N., Ajiboye, R. M., Cheng, I., Hu, S. S., Wood, K. B. 2019; 19 (8): 1324–30

  View details for DOI 10.1016/j.spinee.2019.04.020

  View details for Web of Science ID 000476725600004

• The Association of Financial Distress With Disability in Orthopaedic Surgery. The Journal of the American Academy of Orthopaedic Surgeons Mertz, K., Eppler, S. L., Thomas, K., Alokozai, A., Yao, J., Amanatullah, D. F., Chou, L., Wood, K. B., Safran, M., Steffner, R., Gardner, M., Kamal, R. N. 2019; 27 (11): e522–e528

  Abstract

  INTRODUCTION: Increased out-of-pocket costs have led to patients bearing more of the financial burden for their care. Previous work has shown that financial burden and distress can affect outcomes, symptoms, satisfaction, and adherence to treatment. We asked the following questions: (1) Does patients' financial distress correlate with disability in patients with nonacute orthopaedic conditions? (2) Do patient demographic factors affect this correlation?METHODS: We conducted a cross-sectional, observational study of new patients presenting to a multispecialty orthopaedic clinic with a nonacute orthopaedic complication. Patients completed a demographics questionnaire, the InCharge Financial Distress/Financial Well-Being Scale, and the Health Assessment Questionnaire Disability Index. Statistical analysis was done using Pearson's correlation.RESULTS: The mean score for financial distress was 4.10 (SD, 2.09; scale 1 [low distress] to 10 [high distress]; range, 1.13 to 10.0), and the mean disability score was 0.54 (SD, 0.65; scale 0 to 3; range, 0 to 2.75). A moderate positive correlation exists between financial distress and disability (r = 0.43; P < 0.01). Financial distress and disability were highest for poor, uneducated, Medicare patients.CONCLUSIONS: A moderate correlation exists between financial distress and disability in patients with nonacute orthopaedic conditions, particularly in patients with low socioeconomic status. Orthopaedic surgeons may benefit from identifying patients in financial distress and discussing the cost of treatment because of its association with disability and potentially inferior outcomes. Further investigation is needed to test whether decreasing financial distress decreases disability.LEVEL OF EVIDENCE: Level III prospective cohort.

  View details for DOI 10.5435/JAAOS-D-18-00252

  View details for PubMedID 31125323

• Lumbar epidural steroid injections for herniation and stenosis: incidence and risk factors of subsequent surgery SPINE JOURNAL Koltsov, J. B., Smuck, M. W., Zagel, A., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2019; 19 (2): 199–205

  View details for DOI 10.1016/j.spinee.2018.05.034

  View details for Web of Science ID 000455917700011

• Lateral femoral sliding osteotomy in total knee arthroplasty with valgus deformity greater than twenty degrees. International orthopaedics Li, F., Liu, N., Li, Z., Wood, K. B., Tian, H. 2019

  Abstract

  PURPOSE: Lateral femoral sliding osteotomy has been reported as an effective technique for total knee arthroplasty (TKA) with significant valgus deformity. This study aims to investigate its utility in TKA with valgus deformity greater than 20°, for which few studies have examined.METHODS: Consecutive TKA patients with valgus deformity treated with the sliding osteotomy at our institution were retrospectively studied. Constraint implants were not used. Radiological and clinical parameters at follow-ups were compared with those pre-operatively. Radiological parameters included the hip-knee-ankle angle (HKA), the anatomical lateral distal femoral angle (aLDFA), the anatomical lateral plateau ankle angle (aLPTA), and the angle between the femoral mechanical axis and transepicondylar line (femoral transepicondylar angle, FTEA) which was used to reflect concurrent extra-articular valgus and corresponding local alignment. Clinical outcome measures included the Knee Society Score and Functional Score.RESULTS: Twenty-five patients operated on between July 2011 and February 2017 were enrolled. The average follow-up time was 3.3 (1.5~7.9) years. The pre-operative HKA of 202.7±2.3° (equivalent to valgus of 22.7±2.3°) was reduced to 180.4±2.3° at final follow-ups (P<0.001). The aLFDA, aLPTA, and FTEA were all significantly improved, with the last one increased from 84.2±1.8° to 89.6±1.6° (t=-11.35, P<0.001). All clinical scores were significantly improved without major complications.CONCLUSIONS: Lateral femoral sliding osteotomy can be effective and safe for TKA with severe valgus deformity greater than 20°.

  View details for PubMedID 30659318

• Reliability of Radiological Measurements of Type-2 Odontoid Fracture. The spine journal : official journal of the North American Spine Society Karamian, B. A., Liu, N. n., Ajiboye, R. M., Cheng, I. n., Hu, S. S., Wood, K. B. 2019

  Abstract

  It is recognized that radiological parameters of type 2 dens fractures, including displacement and angulation, are predictive of treatment outcomes and are used to guide surgical decision-making. The reproducibility of such measurements, therefore, is of critical importance. Past literature has shown poor inter-observer reliability for both displacement and angulation measurements of type 2 dens fractures. Since such studies however, various advancements of radiological review systems and measurement tools have evolved to potentially improve such measurements.To re-examine the interrater reliability of measuring displacement and angulation of type 2 dens fractures utilizing modern radiologic review systems. Besides quantitative measurements, the reliability of raters in identifying diagnostic classifications based on translational and angulational displacement was also examined.Radiographic measurement reliability and agreement study.Thirty-seven patients seen at a single institution between 2002 and 2017 with primary diagnosis of acute type II dens fracture with complete CT imaging.Radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cut-off points were also recorded.Measurements were performed by five surgeons with varying years of experience in spine surgery using the hospital's electronic medical record radiological measuring tools. The radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cut-off points were also recorded. Each rater received a graphic demonstration of the measurement methods, but had the autonomy to select a best cut from the sagittal CT to measure. All raters were blinded to patient information.Measurements for displacement and angulation among the five raters demonstrated "excellent" reliability. Intra-rater reliability was also "excellent" in measuring displacement and angulation. The reliability of diagnostic classification of displacement (above vs. below 5mm), was found to be "very good" among the raters. The reliability of diagnostic classification of angulation (above vs. below 11°) demonstrated "good" reliability.Advancement of radiological review systems, including review tools and embedded image processing software, has facilitated more reliable measurements for type-2 odontoid fractures.

  View details for PubMedID 31078698

• Abnormally high dislocation rate following constrained condylar knee arthroplasty for valgus knee: a case-control study. Journal of orthopaedic surgery and research Li, F. n., Liu, N. n., Li, Z. n., Wood, K. B., Tian, H. n. 2019; 14 (1): 268

  Abstract

  With the use of constrained condylar knee (CCK) prostheses, dislocation of the knee following total knee arthroplasty (TKA) with valgus deformity is rare. In our practice with such patients, however, an abnormally high dislocation rate was noted. It appeared to be associated with the extent of soft-tissue release which varied among surgeons following different sequences of release. We asked in CCK TKA with valgus deformity is releasing both the lateral collateral ligament (LCL) and popliteus tendon (PT) associated with the occurrence of dislocation.This is a case-control study of consecutive patients with valgus deformity who underwent primary CCK TKA between July 2008 and October 2015. The cases and controls were patients with and without postoperative dislocation of the knee, respectively. The extent of the release of lateral soft-tissue structures was compared between the two groups. Other patient characteristics including age, body mass index, pre- and post-operative valgus deformity, preoperative flexion-contracture, and height of the polyethylene insert were compared as well to reduce confounding.Forty-three consecutive patients with a minimum 2-year follow-up were enrolled. 9.3% (4/43) of the patients had postoperative dislocation of the knee. While the dislocated patients did not significantly differ from the controls on most characteristics, they were more likely to have both the LCL and PT released together during the surgery [100% (4/4) vs. 2.6% (1/39), P < 0.001].Releasing both LCL and PT in CCK TKA with valgus deformity may increase the risk of dislocation, and need to be performed with some caution.

  View details for DOI 10.1186/s13018-019-1325-4

  View details for PubMedID 31443664

• Postoperative Radiographic Evaluation Following Adult Spine Deformity Correction: The Impact on Subsequent Management and Associated Risk of Radiation Exposure. Spine deformity Boddu, C., Jacobson, M., Curtin, P. B., Lawlor, C. E., Wood, K., Grottkau, B. E. 2019; 7 (1): 146–51

  Abstract

  BACKGROUND: During the follow-up visits after Adult Spine Deformity (ASD) surgery, obtaining surveillance radiographs is a usual practice, and this study tried to identify evidence to support or refute such practice.METHODS: This is a retrospective, diagnostic case series (Level IV) of 49 patients. We identified the abnormal radiographic findings and their association with need for revision surgery. We determined the odds of obtaining an abnormal radiographs that lead to revision surgery at each of the given time intervals of follow-up. We also estimated the risk versus benefit of obtaining radiographs at each of the given time intervals of follow-up.RESULTS: We identified a total of 11 individual types of abnormal postoperative radiographic findings. Of them, the two radiographic findings that always needed revision surgery because of the associated clinical presentation were pedicle screw pullout and bilateral rod fracture. One abnormal radiographic finding that was never associated with revision surgery was the halo around a pedicle screw. In each of the given postoperative time intervals of follow-up at which the routine radiographs were obtained, we noted that the odds of noticing abnormal radiographic finding that lead to revision surgery was always >1. We found that the cumulative hazard rate for exposure to radiation was significantly higher during the initial follow-up visits when compared to subsequent follow-up visits.CONCLUSION: This study finds evidence to support the practice of routine postoperative radiographic evaluation of patients who come for follow-up after ASD surgery.

  View details for PubMedID 30587308

• A Structured Review Instrument Improves the Quality of Orthopaedic Journal Club JOURNAL OF SURGICAL EDUCATION Campbell, S. T., Kleimeyer, J. P., Young, J. L., Gardner, M. J., Wood, K. B., Bishop, J. A. 2019; 76 (1): 294–300

  View details for DOI 10.1016/j.jsurg.2018.06.017

  View details for Web of Science ID 000456356300036

• Postoperative Radiographic Evaluation Following Adult Spine Deformity Correction : The Impact on Subsequent Management and Associated Risk of Radiation Exposure. Spine deformity Boddu, C. n., Jacobson, M. n., Curtin, P. B., Lawlor, C. E., Wood, K. n., Grottkau, B. E. 2019; 7 (1): 146–51

  Abstract

  During the follow-up visits after Adult Spine Deformity (ASD) surgery, obtaining surveillance radiographs is a usual practice, and this study tried to identify evidence to support or refute such practice.This is a retrospective, diagnostic case series (Level IV) of 49 patients. We identified the abnormal radiographic findings and their association with need for revision surgery. We determined the odds of obtaining an abnormal radiographs that lead to revision surgery at each of the given time intervals of follow-up. We also estimated the risk versus benefit of obtaining radiographs at each of the given time intervals of follow-up.We identified a total of 11 individual types of abnormal postoperative radiographic findings. Of them, the two radiographic findings that always needed revision surgery because of the associated clinical presentation were pedicle screw pullout and bilateral rod fracture. One abnormal radiographic finding that was never associated with revision surgery was the halo around a pedicle screw. In each of the given postoperative time intervals of follow-up at which the routine radiographs were obtained, we noted that the odds of noticing abnormal radiographic finding that lead to revision surgery was always > 1. We found that the cumulative hazard rate for exposure to radiation was significantly higher during the initial follow-up visits when compared to subsequent follow-up visits.This study finds evidence to support the practice of routine postoperative radiographic evaluation of patients who come for follow-up after ASD surgery.

  View details for DOI 10.1016/j.jspd.2018.05.017

  View details for PubMedID 31975248

• The Relationship Between Lumbar Lateral Listhesis and Radiculopathy in Adult Scoliosis. Spine Kleimeyer, J. P., Liu, N. n., Hu, S. S., Cheng, I. n., Alamin, T. n., Grottkau, B. E., Kukreja, S. n., Wood, K. B. 2019; 44 (14): 1003–9

  Abstract

  Retrospective review and prospective validation study.To develop a classification system of lumbar lateral listhesis that suggests different likelihoods of having radiculopathy in adult scoliosis.The association of lumbar lateral listhesis with radiculopathy remains uncertain.A retrospective cohort of patients with adult scoliosis enrolled from 2011 to 2015 was studied to develop a classification system of lateral listhesis that can stratify the likelihood of having radiculopathy. Four radiological aspects of lateral listhesis, including Nash and Moe vertebral rotation, L4-L5 lateral listhesis, the number of consecutive listheses, and the presence of a contralateral lateral listhesis at the thoracolumbar junction above a caudal listhesis, were evaluated on radiographs. Their associations with the presence of radicular leg pain were evaluated using multivariable logistic regression. The classification system of lateral listhesis was thus developed using the most influential radiological factors and then validated in a prospective cohort from 2016 to 2017.The retrospective cohort included 189 patients. Vertebral rotation is more than or equal to grade 2 (odds ratio [OR] = 9.45, 95% confidence interval [CI]: 4.07-25.14) and L4-5 listhesis (OR = 4.56, 95%CI: 1.85-12.35) were the two most influential listhesis factors associated with radiculopathy. The classification system of lateral listhesis was thus built based on the combinations of their respective presence: Type 0, 1, 2, 3 were defined as not having listhesis at all, none of the two factors present, one of the two presents, and both present, respectively. This classification significantly stratified the probability of radiculopathy, in both the retrospective cohort (0%, 6.4%, 33.8%, and 68.4% in Type 0, 1, 2, and 3, respectively; P < 0.001) and a prospective cohort of 105 patients (0%, 16.7%, 46.9%, and 72.7%; P < 0.001).Lumbar lateral listhesis is associated with the presence of radiculopathy in adult scoliosis. Types 2 and 3 lateral listhesis on radiographs may alert surgeons treating patients with spinal deformity.2.

  View details for DOI 10.1097/BRS.0000000000002986

  View details for PubMedID 30664100

• Selective Anterior Lumbar Interbody Fusion for Low Back Pain Associated With Degenerative Disc Disease Versus Nonsurgical Management SPINE Kleimeyer, J. P., Cheng, I., Alamin, T. F., Hu, S. S., Cha, T., Yanamadala, V., Wood, K. B. 2018; 43 (19): 1372–80

  Abstract

  This is a retrospective cohort study.To evaluate the long-term outcomes of selective one- to two-level anterior lumbar interbody fusions (ALIFs) in the lower lumbar spine versus continued nonsurgical management.Low back pain associated with lumbar intervertebral disc degeneration is common with substantial economic impact, yet treatment remains controversial. Surgical fusion has previously provided mixed results with limited durable improvement of pain and function.Seventy-five patients with one or two levels of symptomatic Pfirrmann grades 3 to 5 disc degeneration from L3-S1 were identified. All patients had failed at least 6 months of nonsurgical treatment. Forty-two patients underwent one- or two-level ALIFs; 33 continued multimodal nonsurgical care. Patients were evaluated radiographically and the visual analog pain scale (VAS), Oswestry Disability Index (ODI), EuroQol five dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System scores for pain interference, pain intensity, and anxiety. As-treated analysis was performed to evaluate outcomes at a mean follow-up of 7.4 years (range: 2.5-12).There were no differences in pretreatment demographics or nonsurgical therapy utilization between study arms. At final follow-up, the surgical arm demonstrated lower VAS, ODI, EQ-5D, and Patient-Reported Outcomes Measurement Information System pain intensity scores versus the nonsurgical arm. VAS and ODI scores improved 52.3% and 51.1% in the surgical arm, respectively, versus 15.8% and -0.8% in the nonsurgical arm. Single-level fusions demonstrated improved outcomes versus two-level fusions. The pseudarthrosis rate was 6.5%, with one patient undergoing reoperation. Asymptomatic adjacent segment degeneration was identified in 11.9% of patients.Selective ALIF limited to one or two levels in the lower lumbar spine provided improved pain and function when compared with continued nonsurgical care. ALIF may be a safe and effective treatment for low back pain associated with disc degeneration in select patients who fail nonsurgical management.3.

  View details for PubMedID 29529003

• Patient Perceptions Correlate Weakly With Observed Patient Involvement in Decision-making in Orthopaedic Surgery CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Mertz, K., Eppler, S., Yao, J., Amanatullah, D. F., Chou, L., Wood, K. B., Safran, M., Steffner, R., Gardner, M., Kamal, R. 2018; 476 (9): 1859–65

  View details for DOI 10.1097/CORR.0000000000000365

  View details for Web of Science ID 000452513200030

• A Structured Review Instrument Improves the Quality of Orthopaedic Journal Club. Journal of surgical education Campbell, S. T., Kleimeyer, J. P., Young, J. L., Gardner, M. J., Wood, K. B., Bishop, J. A. 2018

  Abstract

  OBJECTIVE: We asked the following questions: 1. Does the use of an structured review instrument (SRI) at journal club increase presentation quality, as measured objectively by a standardized evaluation rubric? 2. Does SRI use increase the time required to prepare for journal club? 3. Does SRI use positively impact presenter perceptions about confidence while presenting, satisfaction, and journal club effectiveness, as measured by postparticipation surveys?DESIGN: A prospective study was designed in which a grading rubric was developed to evaluate journal club presentations. The rubric was applied to 24 presentations at journal clubs prior to introduction of the SRI. An SRI was developed and distributed to journal club participants, who were instructed to use it to prepare for journal club. The grading rubric was then used to assess 25 post-SRI presentations and scores were compared between the pre- and post-SRI groups. Presentations occurred at either trauma, pediatrics, or spine subspecialty journal clubs. Participants were also surveyed regarding time requirements for preparation, perceptions of confidence while presenting, satisfaction, and perceptions of overall club effectiveness.SETTING: A single academic center with an orthopaedic surgery residency program.PARTICIPANTS: Resident physicians in the department of orthopaedic surgery.RESULTS: Mean presentation scores increased from 14.0 ± 5.9 (mean ± standard deviation) to 24.4 ± 5.2 after introduction of the SRI (p < 0.001). Preparation time decreased from a mean of 47 minutes to 40 minutes after SRI introduction (p = 0.22). Perceptions of confidence, satisfaction, and club effectiveness among trainees trended toward more positive responses after SRI introduction (confidence: 63% positive responses pre-SRI vs 72% post-SRI, p = 0.73; satisfaction: 64% vs 91%, p = 0.18; effectiveness: 64% vs 91%, p = 0.19).CONCLUSIONS: The use of a structured review instrument to guide presentations at orthopaedic journal club increased presentation quality, and there was no difference in preparation time. There were trends toward improved presenter confidence, satisfaction, and perception of journal club effectiveness. SRI utilization at orthopaedic journal club may be an effective method for increasing the quality of journal club presentations. Future work should examine the relationship between presentation quality and overall club effectiveness.

  View details for PubMedID 30093334

• Patient Perceptions Correlate Weakly With Observed Patient Involvement in Decision-making in Orthopaedic Surgery. Clinical orthopaedics and related research Mertz, K., Eppler, S., Yao, J., Amanatullah, D. F., Chou, L., Wood, K. B., Safran, M., Steffner, R., Gardner, M., Kamal, R. 2018

  Abstract

  BACKGROUND: Shared decision-making between patients and physicians involves educating the patient, providing options, eliciting patient preferences, and reaching agreement on a decision. There are different ways to measure shared decision-making, including patient involvement, but there is no consensus on the best approach. In other fields, there have been varying relationships between patient-perceived involvement and observed patient involvement in shared decision-making. The relationship between observed and patient-perceived patient involvement in decision-making has not been studied in orthopaedic surgery.QUESTIONS/PURPOSES: (1) Does patient-perceived involvement correlate with observed measurements of patient involvement in decision-making in orthopaedic surgery? (2) Are patient demographics associated with perceived and observed measurements of patient involvement in decision-making?METHODS: We performed a prospective, observational study to compare observed and perceived patient involvement in new patient consultations for eight orthopaedic surgeons in subspecialties including hand/upper extremity, total joint arthroplasty, spine, sports, trauma, foot and ankle, and tumor. We enrolled 117 English-literate patients 18 years or older over an enrollment period of 2 months. A member of the research team assessed observed patient involvement during a consultation with the Observing Patient Involvement in Decision-Making (OPTION) instrument (scaled 1-100 with higher scores representing greater involvement). After the consultation, we asked patients to complete a questionnaire with demographic information including age, sex, race, education, income, marital status, employment status, and injury type. Patients also completed the Perceived Involvement in Care Scale (PICS), which measures patient-perceived involvement (scaled 1-13 with higher scores representing greater involvement). Both instruments are validated in multiple studies in various specialties and the physicians were blinded to the instruments used. We assessed the correlation between observed and patient-perceived involvement as well as tested the association between patient demographics and patient involvement scores.RESULTS: There was weak correlation between observed involvement (OPTION) and patient-perceived involvement (PICS) (r = 0.37, p < 0.01) in decision-making (mean OPTION, 28.7, SD 7.7; mean PICS, 8.43, SD 2.3). We found a low degree of observed patient involvement despite a moderate to high degree of perceived involvement. No patient demographic factor had a significant association with patient involvement.CONCLUSIONS: Further work is needed to identify the best method for evaluating patient involvement in decision-making in the setting of discordance between observed and patient-perceived measurements. Knowing whether it is necessary for (1) actual observable patient involvement to occur; or (2) a patient to simply believe they are involved in their care can inform physicians on the best way to improve shared decision-making in their practice.LEVEL OF EVIDENCE: Level II, therapeutic study.

  View details for PubMedID 29965894

• Lumbar Epidural Steroid Injections for Herniation and Stenosis: Incidence and Risk Factors of Subsequent Surgery. The spine journal : official journal of the North American Spine Society Koltsov, J. C., Smuck, M. W., Zagel, A., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2018

  Abstract

  BACKGROUND CONTEXT: Lumbosacral ESIs have increased dramatically despite a narrowing of the clinical indications for use. One potential indication is to avoid or delay surgery, yet little information exists regarding surgery rates after ESI.PURPOSE: The purpose of this research was to determine the proportion of patients having surgery after lumbar epidural steroid injection (ESI) for disc herniation or stenosis and to identify the timing and factors associated with this progression STUDY DESIGN/SETTING: This study was a retrospective review of nationally-representative administrative claims data from the Truven Health MarketScan databases from 2007 - 2014.PATIENT SAMPLE: The study cohort was comprised of 179,025 patients (54±15 years, 48% female) having lumbar epidural steroid injections (ESIs) for diagnoses of stenosis and/or herniation.OUTCOME MEASURES: The primary outcome measure was the time from ESI to surgery.METHODS: Inclusion criteria were ESI for stenosis and/or herniation, age ≥18 years, and health plan enrollment for 1 year prior to ESI to screen for exclusions. Patients were followed longitudinally until they progressed to surgery or had a lapse in enrollment, at which time they were censored. Rates of surgery were assessed with the Kaplan-Meier survival curves. Demographic and treatment factors associated with surgery were assessed with multivariable Cox proportional hazard models. No external funding was procured for this research and the authors' conflicts of interest are not pertinent to the present work.RESULTS: Within 6 months, 12.5% of ESI patients underwent lumbar surgery. By 1 year, 16.9% had surgery, and by 5 years, 26.1% had surgery. Patients with herniation had surgery at rates of up to 5 to 7 fold higher, with the highest rates of surgery in younger patients and those with both herniation and stenosis. Other concomitant spine diagnoses, male sex, previous tobacco use, and residence a rural areas or regions other than the Northeastern United States were associated with higher surgery rates. Medical comorbidities (previous treatment for drug use, CHF, obesity, COPD, hypercholesterolemia, and other cardiac complications) were associated with lower surgery rates.CONCLUSIONS: In the long-term, more than 1 out of every 4 patients undergoing ESI for lumbar herniation or stenosis subsequently had surgery, and nearly 1 of 6 had surgery within the first year. After adjusting for other patient demographics and comorbidities, patients with herniation were more likely have surgery than those with stenosis. The improved understanding of the progression from lumbar ESI to surgery will help to better inform discussions regarding the value of ESI and aid in the shared decision making process.

  View details for PubMedID 29959098

• What Is the State of Quality Measurement in Spine Surgery? CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Bennett, C., Xiong, G., Hu, S., Wood, K., Kamal, R. N. 2018; 476 (4): 725–31

  Abstract

  Value-based healthcare models rely on quality measures to evaluate the efficacy of healthcare delivery and to identify areas for improvement. Quality measure research in other areas of health care has generally shown that there is a limited number of available quality measures and that those that exist disproportionately focus on processes as opposed to outcomes. The purpose of this study was to assess the current state of quality measures and candidate quality measures in spine surgery.(1) How many quality measures and candidate quality measures are currently available? (2) According to Donabedian domains and National Quality Strategy (NQS) priorities, what aspects or domains of care do the present quality measures and candidate quality measures represent?We systematically reviewed the National Quality Forum, the Agency for Healthcare Research and Quality, and the Physician Quality Reporting System for quality measures relevant to spine surgery. A systematic search for candidate quality measures was also performed using MEDLINE/PubMed and Embase as well as publications from the American Academy of Orthopaedic Surgeons, Congress of Neurological Surgeons, and the North American Spine Society. Clinical practice guidelines were included as candidate quality measures if their development was in accordance with Institute of Medicine criteria for the development of clinical practice guidelines, they were based on consistent clinical evidence including at least one Level I study, and they carried the strongest possible recommendation by the developing body. Quality measures and candidate quality measures were then pooled for analysis and categorized by clinical focus, NQS priority, and Donabedian domain. Our initial search yielded a total of 3940 articles, clinical practice guidelines, and quality measures, 74 of which met criteria for inclusion in this study.Of the 74 measures studied, 29 (39%) were quality measures and 45 (61%) were candidate quality measures. Fifty of 74 (68%) were specific to the care of the spine, and 24 of 74 (32%) were related to the general care of spine patients. The majority of the spine-specific measures were process measures (45 [90%]) and focused on the NQS priority of "Effective Clinical Care" (44 [88%]). The majority of the general care measures were also process measures (14 [58%]), the highest portion of which focused on the NQS priority of "Patient Safety" (10 [42%]).Given the large number of pathologies treated by spine surgeons, the limited number of available quality measures and candidate quality measures in spine surgery is inadequate to support the transition to a value-based care model. Additionally, current measures disproportionately focus on certain aspects or domains of care, which may hinder the ability to appropriately judge an episode of care, extract usable data, and improve quality. Physicians can steward the creation of meaningful quality measures by participating in clinical practice guideline development, assisting with the creation and submission of formal quality measures, and conducting the high-quality research on which effective guidelines and quality measures depend.

  View details for PubMedID 29480884

• Commentary of Acute and Hyperacute Thoracolumbar Corpectomy for Traumatic Burst Fractures Using a Mini-open Lateral Approach SPINE Wood, K. B. 2018; 43 (2): E125

  View details for PubMedID 28858187

• Does timing of transplantation of neural stem cells following spinal cord injury affect outcomes in an animal model? Journal of spine surgery (Hong Kong) Cheng, I., Park, D. Y., Mayle, R. E., Githens, M., Smith, R. L., Park, H. Y., Hu, S. S., Alamin, T. F., Wood, K. B., Kharazi, A. I. 2017; 3 (4): 567–71

  Abstract

  Background: We previously reported that functional recovery of rats with spinal cord contusions can occur after acute transplantation of neural stem cells distal to the site of injury. To investigate the effects of timing of administration of human neural stem cell (hNSC) distal to the site of spinal cord injury on functional outcomes in an animal model.Methods: Thirty-six adult female Long-Evans hooded rats were randomized into three experimental and three control groups with six animals in each group. The T10 level was exposed via posterior laminectomy, and a moderate spinal cord contusion was induced by the Multicenter Animal Spinal Cord Injury Study Impactor (MASCIS, W.M. Keck Center for Collaborative Neuroscience, Piscataway, NJ, USA). The animals received either an intrathecal injection of hNSCs or control media through a separate distal laminotomy immediately, one week or four weeks after the induced spinal cord injury. Observers were blinded to the interventions. Functional assessment was measured immediately after injury and weekly using the Basso, Beattie, Bresnahan (BBB) locomotor rating score.Results: A statistically significant functional improvement was seen in all three time groups when compared to their controls (acute, mean 9.2 vs. 4.5, P=0.016; subacute, mean 11.1 vs. 6.8, P=0.042; chronic, mean 11.3 vs. 5.8, P=0.035). Although there was no significant difference in the final BBB scores comparing the groups that received hNSCs, the group which achieved the greatest improvement from the time of cell injection was the subacute group (+10.3) and was significantly greater than the chronic group (+5.1, P=0.02).Conclusions: The distal intrathecal transplantation of hNSCs into the contused spinal cord of a rat led to significant functional recovery of the spinal cord when injected in the acute, subacute and chronic phases of spinal cord injury (SCI), although the greatest gains appeared to be in the subacute timing group.

  View details for PubMedID 29354733

• Comparison of Decompression With and Without Fusion for Patients With Synovial Facet Cysts CLINICAL SPINE SURGERY van Dijke, M., Janssen, S. J., Cha, T. D., Wood, K. B., Borges, L. F., Harris, M. B., Bono, C. M., Schwab, J. H. 2017; 30 (10): E1399–E1404

  Abstract

  This is a retrospective study.To compare (1) recurrence of radiculopathy and (2) back pain after decompression with and without fusion for patients with a symptomatic synovial cyst.Previous work described favorable outcomes following cyst excision with and without fusion. Because of the association of facet cysts with spinal instability it is hypothesized that a decompression with fusion will lead to better outcomes. However, previous studies present contradicting results.We included 314 consecutive patients that underwent operative treatment for a facet cyst between 2003 and 2013 at 2 tertiary spine referral centers: 224 (71%) underwent decompression without fusion (35% spondylolisthesis), 90 (29%) underwent decompression with fusion (63% spondylolisthesis). Baseline data were compared between the groups. Bivariate log-rank analysis was used to compare outcomes between groups, followed by multivariable Cox regression analysis accounting for differences in baseline characteristics.Patients undergoing decompression with fusion presented with a higher incidence of back pain (P=0.004) and spondylolisthesis (P<0.001), had more often bilateral decompressions (P<0.001), more facetectomies (P<0.001), and more levels of decompression (P=0.004) than those who underwent decompression alone. We found a difference in recurrence of radiculopathy (no fusion: 25% vs. fusion: 9.4%, P=0.029) in bivariate analysis. However, this difference did not hold when accounting for confounders (hazard ratio, 0.50, 95% confidence interval, 0.19-1.31, P=0.16). There was no difference in recurrence of back pain in bivariate (no fusion: 29% vs. fusion: 22%, P=0.51) and multivariable analysis (hazard ratio 0.51, 95% confidence interval, 0.23-1.14, P=0.10).We found, with the numbers evaluated, no difference in recurrence of radiculopathy or back pain between patients undergoing decompression with or without fusion after accounting for confounders. The decision for fusion should be considered in light of the extent of decompression and the existence of other pathology.Level III-therapeutic study.

  View details for PubMedID 27753698

• Surgery for Refractory Coccygodynia SPINE Kleimeyer, J. P., Wood, K. B., Lonne, G., Herzog, T., Ju, K., Beyer, L., Park, C. 2017; 42 (16): 1214–19

  Abstract

  This is a retrospective cohort study.To evaluate the long-term outcomes for patients with refractory coccygodynia treated with coccygectomy compared to a nonsurgical regimen of sitting aids, physical therapy, medications, and injections.The surgical treatment of coccygodynia remains controversial. To date, there has only been one small comparative study of surgical versus nonsurgical treatment.From 2004 to 2014, 109 patients presenting with coccygodynia were treated with either total coccygectomy or a nonsurgical course of sitting aids, physical therapy, anti-inflammatory medications, and injections. All had at least 2 years of symptoms before surgery. The patient principally made the treatment decision, counseled by the treating physician. Before surgery, all subjects underwent at least 2 years of conservative treatment and three-dimensional imaging (computed tomography and/or magnetic resonance imaging). Subjects completed visual analog pain scales, EuroQol five-dimension, components of the PROMIS measure, and a novel Coccygodynia Disability Index evaluation. Work status, complications, and satisfaction were recorded.A total of 61 patients received nonsurgical care; eight declined participation and five could not be located. Forty-eight patients underwent total coccygectomy; three declined participation and five could not be located. At an average 4.8 years of follow-up (range: 2-9), the nonsurgical visual analog pain scales was 5 and the surgical 2 (P = 0.001); 79% of surgically treated patients were improved at 2 years versus 43% for the nonsurgical group. EuroQol five-dimension (P = 0.002), Coccygodynia Disability Index (0.01), and PROMIS Pain interference scores (0.02) were also significantly improved in the surgical group. Eleven surgical patients (26%) had complications, all wound related with successful resolution; seven treated with dressing changes and four with surgical debridement.Total coccygectomy is a safe and effective surgical treatment of coccygodynia refractory to nonoperative care. Patient-reported outcome measures were improved after surgery compared with nonsurgical management. Postoperative wound care remains a concern.4.

  View details for PubMedID 28800569

• Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion-Extension of the Neck JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME Yu, Y., Mao, H., Li, J., Tsai, T., Cheng, L., Wood, K. B., Li, G., Cha, T. D. 2017; 139 (6)

  Abstract

  While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

  View details for PubMedID 28334358

• In Vivo Characteristics of Nondegenerated Adjacent Segment Intervertebral Foramina in Patients With Degenerative Disc Disease During Flexion-Extension SPINE Cha, T. D., Moore, G., Liow, M., Zhong, W., Wu, M., Wang, S., Kang, J. D., Wood, K. B., Li, G. 2017; 42 (6): 359–65

  Abstract

  In vivo patient biomechanical study.To investigate the dimensions of lumbar intervertebral foramen (LIVF) of patients with degenerative disc disease (DDD) during a flexion-extension motion of the body.LIVF narrowing may result in nerve root compression. The area changes of degenerated and adjacent nondegenerated LIVFs in DDD patients under physiologic loading conditions are unknown.Nine symptomatic low back pain patients with radiological evidence of L4-S1 DDD were recruited. Each subject was magnetic resonance imaging scanned for construction of three-dimensional lumbar vertebral models, and fluoroscopically imaged when the body extended from 45 flexion to full extension for reconstruction of LIVF dimensions. The data of the adjacent segment L3/4 and diseased segments L4/5 and L5/S1 were compared with a normal control group at 45 flexion, upright, and full extension of the body.The mean LIVF areas of DDD segments were significantly smaller than those of the normal subjects in all positions (P <0.05). In upright position, the LIVF areas of the DDD patients were 32.8% and 33.6% smaller than the normal subjects for L4/5 and L5/S1, respectively. For the adjacent L3/4, the LIVF area of the DDD patients was 32.3% smaller than that of the normal controls (P <0.05). The total change of L3/4 LIVF area in DDD patients from flexion to extension was significantly smaller than that of the normal subjects, but the changes in L4/5 and L5/S1 LIVF areas were similar between the two groups (P >0.05).Similar reductions of the LIVF dimensions were observed at the adjacent and the involved levels of the DDD patients, implying that biomechanical changes might have already occurred at the adjacent segment despite the lack of radiographic evidence of degeneration. Subsequent research should focus on the effects of surgical fusion on the biomechanical features of the adjacent segment.N/A.

  View details for PubMedID 27379419

• Multiple-hook fixation in revision spinal deformity surgery for patients with a previous multilevel fusion mass: technical note and preliminary outcomes JOURNAL OF NEUROSURGERY-SPINE Liu, N., Wood, K. B. 2017; 26 (3): 368-373

  Abstract

  OBJECTIVE A previous multilevel fusion mass encountered during revision spinal deformity surgery may obscure anatomical landmarks, making instrumentation unworkable or incurring substantial blood loss and operative time. This study introduced a surgical technique of multiple-hook fixation for fixating previous multilevel fusion masses in revision spinal deformity surgeries and then evaluated its outcomes. METHODS Patients with a previous multilevel fusion mass who underwent revision corrective surgery down to the lumbosacral junction were retrospectively studied. Multiple hooks were used to fixate the fusion mass and linked to distal pedicle screws in the lumbosacral-pelvic complex. Radiological and clinical outcomes were evaluated. RESULTS The charts of 8 consecutive patients with spinal deformity were retrospectively reviewed (7 women, 1 man; mean age 56 years). The primary diagnoses included flat-back deformity (6 cases), thoracolumbar kyphoscoliosis (1 case), and lumbar spondylosis secondary to a previous scoliosis fusion (1 case). The mean follow-up duration was 30.1 months. Operations were performed at T3/4-ilium (4 cases), T7-ilium (1 case), T6-S1 (1 case), T12-S1 (1 case), and T9-L5 (1 case). Of 8 patients, 7 had sagittal imbalance preoperatively, and their mean C-7 plumb line improved from 10.8 ± 2.9 cm preoperatively to 5.3 ± 3.6 cm at final follow-up (p = 0.003). The mean lumbar lordosis of these patients at final follow-up was significantly greater than that preoperatively (35.2° ± 12.6° vs 16.8° ± 11.8°, respectively; p = 0.005). Two perioperative complications included osteotomy-related leg weakness in 1 patient and a stitch abscess in another. CONCLUSIONS The multiple-hook technique provides a viable alternative option for fixating a previous multilevel fusion mass in revision spinal deformity surgery.

  View details for DOI 10.3171/2016.8.SPINE16432

  View details for PubMedID 27935449

• The effect of short (2-weeks) versus long (6-weeks) post-operative restrictions following lumbar discectomy: a prospective randomized control trial. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society Bono, C. M., Leonard, D. A., Cha, T. D., Schwab, J. H., Wood, K. B., Harris, M. B., Schoenfeld, A. J. 2017; 26 (3): 905-912

  Abstract

  We sought to evaluate how short (2-week) versus long (6-week) post-operative restrictions following lumbar discectomy impacted outcomes and reherniation rates for a period up to 1 year following surgery.This study included 108 patients undergoing index lumbar discectomy. Patients were randomized immediately following surgery. Outcomes included back and leg visual analog pain scales (VAS), Oswestry Disability Index (ODI), and reherniation rates at 2-weeks, 6-weeks, 3-months, and 1-year following surgery. Differences in reherniation rates were analyzed using Fisher's exact test. VAS and ODI scores were evaluated using Student's t test.Six patients (11%) in the 2-week restriction group had a reherniation event and four patients (7%) in the 6-week restriction group experienced a reherniation (p = 0.52). VAS back pain (p < 0.001), leg pain (p < 0.001), and ODI scores (p < 0.001) were significantly improved for both cohorts as compared to baseline at the 2-week time point and remained significantly improved through 1-year [VAS back (p < 0.001); VAS leg (p < 0.001); ODI (p < 0.001)]. No significant differences in ODI, VAS back, or VAS leg scores were detected at any of the time points between the 2- and 6-week restriction groups.The results of this randomized trial suggest equivalent clinical outcomes irrespective of the length of post-operative restriction. From a clinical perspective, if patients are deemed at low risk for a reherniation event they may be confidence that early return to activity at 2 weeks will not compromise outcomes and may not adversely impact the risk of reherniation. Level of Evidence II.

  View details for DOI 10.1007/s00586-016-4821-9

  View details for PubMedID 27807771

• The effect of short (2-weeks) versus long (6-weeks) post-operative restrictions following lumbar discectomy: a prospective randomized control trial EUROPEAN SPINE JOURNAL Bono, C. M., Leonard, D. A., Cha, T. D., Schwab, J. H., Wood, K. B., Harris, M. B., Schoenfeld, A. J. 2017; 26 (3): 905-912

  Abstract

  We sought to evaluate how short (2-week) versus long (6-week) post-operative restrictions following lumbar discectomy impacted outcomes and reherniation rates for a period up to 1 year following surgery.This study included 108 patients undergoing index lumbar discectomy. Patients were randomized immediately following surgery. Outcomes included back and leg visual analog pain scales (VAS), Oswestry Disability Index (ODI), and reherniation rates at 2-weeks, 6-weeks, 3-months, and 1-year following surgery. Differences in reherniation rates were analyzed using Fisher's exact test. VAS and ODI scores were evaluated using Student's t test.Six patients (11%) in the 2-week restriction group had a reherniation event and four patients (7%) in the 6-week restriction group experienced a reherniation (p = 0.52). VAS back pain (p < 0.001), leg pain (p < 0.001), and ODI scores (p < 0.001) were significantly improved for both cohorts as compared to baseline at the 2-week time point and remained significantly improved through 1-year [VAS back (p < 0.001); VAS leg (p < 0.001); ODI (p < 0.001)]. No significant differences in ODI, VAS back, or VAS leg scores were detected at any of the time points between the 2- and 6-week restriction groups.The results of this randomized trial suggest equivalent clinical outcomes irrespective of the length of post-operative restriction. From a clinical perspective, if patients are deemed at low risk for a reherniation event they may be confidence that early return to activity at 2 weeks will not compromise outcomes and may not adversely impact the risk of reherniation. Level of Evidence II.

  View details for DOI 10.1007/s00586-016-4821-9

  View details for Web of Science ID 000396042000040

• Lumbar Osteotomy SPINE Wood, K. B. 2016; 41 (7): A23-A23

  Abstract

  When a patient presents with spine problems, the spine surgeon would do well to avoid use of, reliance on, and acceptance of radiographs as the sole or primary source of information. Measurement of pelvic incidence and lumbar lordosis, although crucial, does not take into account the effort the patient must make to move, the level of involvement of other parts of the body, and the history of previous procedures and outcomes. Radiographs may show pathology that is not consistent with the appearance of the patient. How should we assess this situation?

  View details for DOI 10.1097/BRS.0000000000001441

  View details for Web of Science ID 000374878500015

• Lumbar Osteotomy. Spine Wood, K. B. 2016; 41 Suppl 7: S23

  Abstract

  When a patient presents with spine problems, the spine surgeon would do well to avoid use of, reliance on, and acceptance of radiographs as the sole or primary source of information. Measurement of pelvic incidence and lumbar lordosis, although crucial, does not take into account the effort the patient must make to move, the level of involvement of other parts of the body, and the history of previous procedures and outcomes. Radiographs may show pathology that is not consistent with the appearance of the patient. How should we assess this situation?

  View details for DOI 10.1097/BRS.0000000000001441

  View details for PubMedID 27015064

• GAMMA-RAY FLARE ACTIVITY FROM PSR B1259-63 DURING 2014 PERIASTRON PASSAGE AND COMPARISON TO ITS 2010 PASSAGE ASTROPHYSICAL JOURNAL Caliandro, G. A., Cheung, C. C., Li, J., Scargle, J. L., Torres, D. F., Wood, K. S., Chernyakova, M. 2015; 811 (1)

  View details for DOI 10.1088/0004-637X/811/1/68

  View details for Web of Science ID 000363471600069

• CLASS SIZE AND STUDENT EVALUATIONS OF FACULTY JOURNAL OF HIGHER EDUCATION Wood, K., LINSKY, A. S., Straus, M. A. 1974; 45 (7): 524-534

  View details for Web of Science ID A1974U610500004