J. Prescott Chan, MD

All Publications

• The Performance of Prognostic Measures for Survival in Spinal Metastatic Disease in Light of Modern Advancements in Medical and Surgical Management. Spine Striano, B. M., Ferrone, M. L., Holly, K. E., Zheng, C., Nguyen, A., Macksood, J., Osgood, A., Coan, J. M., Chan, J. P., Cronin, P. K., Tobert, D. G., Schoenfeld, A. J. 2026

  Abstract

  Retrospective cohort.To compare the performance of four of the most widely used scoring systems for survival in spinal metastatic disease among a representative battery of cases treated in our health system during 2017-2022.None of the popular risk scores in use today effectively account for improved survival due to advancements in immunotherapy, molecular targeted treatment and surgical techniques.We assembled a representative battery of 997 patients who underwent operative or non-operative treatment for spinal metastases (2017-22). All patients were assigned a Tokuhashi, Tomita, Skeletal Oncology Research Group (SORG) and New England Spinal Metastasis Score (NESMS) based on data at initial presentation. The primary outcome was the discriminative capacity of the scoring utilities in predicting one-year mortality. This was evaluated using multivariable logistic regression with all variables included as co-variates. The discriminative capacity for each model was compared using the c-statistic. We also assessed the performance of operative management in conjunction with the survival score.One year mortality was 54%. The SORG's c-statistic was 0.75 (95% CI 0.71, 0.78), compared to 0.68 (95% CI 0.65, 0.71) for the NESMS. The c-statistic for the Tokuhashi score was 0.70 (95% CI 0.67, 0.73), while that of the Tomita scale was 0.66 (95% CI 0.63, 0.69). Only the SORG (OR 0.64; 95% CI 0.46, 0.90; P=0.01) and NESMS (OR 0.74; 95% CI 0.56, 0.97; P=0.03) preserved a significant association between surgical intervention and survival.We found that the performance of all scores were diminished relative to historical reports but remained adequate for the NESMS and SORG algorithm. In current practice, we believe the optimal approach entails initial use of the NESMS when considering treatment approach, with the SORG used for re-calculating survival if surgical intervention has been selected as a treatment strategy.III.

  View details for DOI 10.1097/BRS.0000000000005741

  View details for PubMedID 42202761

• Revisiting Survival in the Treatment of Spinal Metastases from Lung Cancer in the Modern Era of Immunotherapy and Molecular Targeted Treatment (2017-2022). Spine Striano, B. M., Ferrone, M. L., Holly, K. E., Zheng, C., Nguyen, A., Macksood, J., Osgood, A., Coan, J. M., Chan, J. P., Cronin, P. K., Tobert, D. G., Schoenfeld, A. J. 2026

  Abstract

  Retrospective cohort.To assess survival among patients with spinal metastases from lung cancer treated over a time period that accounts for advances in immunotherapy and targeted treatments.The use of immunotherapy and targeted treatments has improved survival for patients with lung cancer, questioning whether secular trends have ushered in a new landscape in the field of spinal metastases.We identified patients who underwent operative or non-operative treatment for spinal metastases (2017-22). The primary outcome was one-year survival. We used multivariable logistic regression analysis to adjust for confounders, including all variables abstracted as co-variates based on conceptual model. We also assessed for interactions between lung cancer and surgical intervention and surgical intervention and immunotherapy.We included 997 patients, with 228 (22.9%) possessing a primary lung cancer diagnosis. At one year, lung cancer was significantly associated with the odds of mortality (OR 2.01; 95% CI 1.44, 2.82). Surgical intervention (OR 0.70; 95% CI 0.53, 0.92), serum albumin of 3.5 g/dL or greater (OR 0.34; 95% CI 0.24, 0.47) and ambulatory status (OR 0.47; 95% CI 0.34, 0.64) were all significantly associated with reduced likelihood of mortality. There was no significant association between immunotherapy and one-year survival (OR 0.82; 95% CI 0.61, 1.11; P=0.19). At 30- (OR 0.55; 95% CI 0.29, 0.98) and 90-days (OR 0.65; 95% CI 0.45, 0.93) immunotherapy was significantly associated with survival.One-year survival in the cohort of patients with spinal metastases derived from lung cancer was significantly lower than that of metastases from other cancers. Surgical intervention did not mitigate this fact. Immunotherapy may exert an effect on near-term survival only. The signals for some of these temporal changes are robust enough to warrant consideration of their impact on traditional prognostic utilities in the future.III.

  View details for DOI 10.1097/BRS.0000000000005723

  View details for PubMedID 42085700

• Navigating Ankle Fracture Surgery in the Shadow of COVID-19. Foot & ankle specialist Chan, J. P., Hoang, H., Anderson, A., Hsu, A. R. 2026; 19 (2): 187-195

  Abstract

  BackgroundThis case control study aimed to evaluate the impact of preoperative COVID-19 diagnosis on postoperative complications in patients undergoing ankle fracture surgery using the National COVID-19 Cohort Collaborative (N3C) database. The investigation focused on the interplay between COVID-19 diagnosis timing, patient characteristics, and clinical outcomes, particularly considering the potential mechanisms by which COVID-19 may contribute to increased complications.MethodsThis case control study included patients who underwent ankle fracture surgery using the N3C database. The cohort was divided into two groups: patients without COVID-19 diagnosis within 12 weeks of surgery (n = 16 806) and those with a positive COVID-19 diagnosis within 12 weeks of surgery (n = 369). Demographic factors were analyzed. Clinical outcomes encompassed deep vein thrombosis (DVT), sepsis, surgical site infection, bleeding, acute kidney injury, 30-day mortality, and 365-day mortality. Multivariate logistic regression analyses were conducted.ResultsThe COVID-19-positive cohort displayed a slightly higher mean age (52.95 ± 18.43 vs 51.62 ± 18.36, P = .169) and body mass index (34.88 ± 9.99 vs 33.86 ± 8.80, P = .028) compared to the negative cohort. Although some outcomes, such as DVT and sepsis, demonstrated slightly higher frequencies in the COVID-19-positive group, these differences were not statistically significant. Adjusted odds ratios (AORs) for various COVID-19 diagnosis periods were generally not significant, except for a heightened risk of 30-day all-cause mortality associated with COVID-19 positivity within 0 to 2 weeks of surgery (AOR = 6.29, P = .003).ConclusionsPreoperative COVID-19 diagnosis within 12 weeks did not exhibit a significant association with most postoperative complications. While this study did not unveil substantial COVID-19-related effects, acknowledging the broader context of the pandemic remains essential in guiding comprehensive patient care strategies.Level of Evidence:Level III.

  View details for DOI 10.1177/19386400241274539

  View details for PubMedID 39305045

  View details for PubMedCentralID PMC12957410

• What is the learning curve for endoscopic spine surgery? A comprehensive systematic review. The spine journal : official journal of the North American Spine Society Chan, J. P., Olson, T., Gabriel, B., Hashmi, S., Wu, H. H., Bow, H., Lee, Y. P., Bhatia, N., Oh, M., Park, D. Y. 2026; 26 (3): 438-449

  Abstract

  Endoscopic spine surgery (ESS) is rapidly emerging as a viable minimally invasive technique to successfully treat symptomatic degenerative spinal conditions. Widespread adoption has been limited in part due to the learning curve.To systematically review the learning curve for uniportal and biportal ESS and compare the 2 techniques.A systematic review based on PRISMA guidelines.About 29 studies were included with 18 studies investigating uniportal learning curves and 11 biportal studies. There were 1,493 patients across all uniportal studies. There was a total of 1,005 patients across all biportal studies.Number of patients, technique type, patient reported outcomes, complications, operative time before the learning curve threshold, operative time after learning curve threshold, number of cases required to meet threshold, number of surgeons in the study, and cases per surgeon were collected and analyzed.A comprehensive literature search was conducted using PubMed, Medline, and Embase from 2000 to present date. Data was extracted by 3 independent reviewers.The learning curve studies were reviewed and summarized. The overall median number of cases to reach the learning curve threshold was significantly less in uniportal vs biportal studies (20 vs 37.5, p=.0463). When stratifying by various procedures, there was no significant difference between the techniques with number of cases required or improvement of operative time. Operative time for biportal discectomies decreased by a significantly greater amount vs uniportal (44.5% vs 21.4%, p=.0332).The learning curve literature for ESS was systematically reviewed and ways to overcome the learning curve were discussed. The overall median number of cases for the learning curve was significantly fewer in uniportal vs biportal but the improvement in operative time was significantly greater with biportal discectomies, typically the entry level procedure by novice surgeons. Overcoming the learning curve for ESS is a critical factor to widespread adoption and understanding it may aid surgeons in progressing to proficiency while mitigating the risk of complications.

  View details for DOI 10.1016/j.spinee.2025.01.004

  View details for PubMedID 39880043

• Non-tobacco nicotine dependence increases risk of complications following lumbar spine decompression and fusion. North American Spine Society journal Spitzer, C., Romoff, M., Brunette, M., Peterson, M. K., Ton, A., Le, R., Sharma, A., Chan, J. P., Wu, H. H., Hashmi, S., Kim, M. S. 2025; 24: 100790

  Abstract

  Non-tobacco nicotine products (eg, e-cigarettes, nicotine pouches) are increasingly used by cigarette smokers and prior nonsmokers. While the detrimental effects of cigarette dependence (CD) on healing and surgical recovery are well documented, the impact of non-tobacco nicotine dependence (NTND) on outcomes after lumbar spine surgery remains poorly characterized.We conducted a retrospective cohort study using the TriNetX database. Patients undergoing lumbar spine decompression and fusion were divided into 3 cohorts: NTND, CD, and controls (no documented nicotine dependence). Propensity score matching was performed 1:1 based on demographic and clinical characteristics. Complication rates were assessed at 90 days and 3 years postoperatively. Outcomes included anemia, deep vein thrombosis (DVT), myocardial infarction (MI), pneumonia, renal failure, pulmonary embolism (PE), sepsis, stroke, opioid abuse, pseudoarthrosis, and lumbar fracture.A total of 39,195 matched NTND and control patients were analyzed. NTND was associated with increased 90-day risks of anemia, DVT, MI, pneumonia, renal failure, sepsis, stroke, and opioid abuse, as well as higher 3-year risks of pseudoarthrosis and lumbar fracture (p < .05). In a comparison of 36, 877 matched NTND and CD patients, NTND showed higher anemia risk but lower risks of MI, PE, renal failure, sepsis, stroke, and opioid abuse at 90 days. At 3 years, NTND carried a higher pseudoarthrosis risk but lower lumbar fracture risk relative to CD (p < .0001). When NTND and CD patients were combined (n = 102,720 total), both groups demonstrated significantly higher complications risks compared with controls at both 90 days and 3 years (p < .0001).NTND is associated with increased perioperative and long-term complications following lumbar spine surgery, including higher rates of infection, opioid abuse, pseudoarthrosis, and lumbar fracture. NTND demonstrates a distinct complication profile compared to CD, underscoring the need for further research on the impact of non-tobacco nicotine exposure on spinal fusion outcomes.

  View details for DOI 10.1016/j.xnsj.2025.100790

  View details for PubMedID 41089422

  View details for PubMedCentralID PMC12516565

• Predicting Likelihood to Repeat Elective Hand Surgery with Early Quick Disabilities of the Arm, Shoulder and Hand Scores: A Feasibility Study. Journal of hand surgery global online London, D. A., Schroeder, A. M., Chan, J. P., Franko, O. I. 2025; 7 (6): 100813

  Abstract

  Patient-reported outcome measures (PROMs) are collected after treatment to assess patient improvement. We sought to determine the postoperative timepoint at which changes in PROMs would best predict patients' likelihood to repeat surgery and offer clinically relevant information.Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores were collected during the course of care of 883 patients before undergoing elective outpatient hand surgery and at 5 postoperative timepoints. Likelihood to repeat surgery was collected 1 year after surgery, and patients were dichotomized into likely and unlikely to repeat surgery groups. Differences in the change in QuickDASH scores between groups were compared using Mann-Whitney U tests. Receiver operating characteristic curves were used in conjunction with Youden's index to determine the timepoints and cutoff levels at which likelihood to repeat surgery could be successfully predicted.In our cohort of 883 patients, 88.3% of patients indicated 1 year after surgery that they would be willing to repeat surgery. Receiver operating characteristic analyses demonstrated that changes in QuickDASH scores at 3, 12, 24, and 52 weeks were all significantly associated with patient likelihood to repeat surgery. A change in QuickDASH score of 10.0 three weeks after surgery was the ideal cutoff point to identify an association of patient likelihood to repeat elective hand surgery 1 year after surgery.Changes in QuickDASH scores as early as 3 weeks after surgery were associated with patient likelihood to repeat elective hand surgery 1 year after surgery. Although the heterogeneity of procedures included in the analyzed data pool precludes the complete generalizability of these findings to current clinical practice, it does support a feasible utility for early PROM collection in predicting patient satisfaction with their surgical outcome. This finding supports the continued, focused study of early PROMs, with potential for their employment in various clinical applications including real-time analysis for early postoperative intervention.Therapeutic IIIb.

  View details for DOI 10.1016/j.jhsg.2025.100813

  View details for PubMedID 41356615

  View details for PubMedCentralID PMC12675804

• Timing of total joint arthroplasty post-COVID-19: an evaluation of the optimal window to minimize perioperative risks. Arthroplasty (London, England) Hoang, H., Gabriel, B., Lung, B., Yang, S., Chan, J. P. 2024; 6 (1): 53

  Abstract

  Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are commonly performed orthopedic procedures. This study aimed to evaluate the impact of COVID-19 status on postoperative complications and mortality in patients undergoing THA and TKA.A total of 110,186 underwent either THA or TKA. Patients were grouped based on their COVID-19 status, gathered from the National COVID-19 Cohort Collaborative (N3C) in the 12 weeks preceding surgery and compared for various variables, including age, sex, BMI, and Charlson Comorbidity Index (CCI) scores. COVID-19 status was defined as a positive test result that was closest to the date of surgery regardless of testing positive previously. Postoperative complications such as venous thromboembolism (VTE), sepsis, surgical site infection, bleeding, acute kidney injury (AKI), 30-day, and 1-year all-cause mortality were examined. To compare the variables, an odds ratio with a 95% confidence interval was calculated with a significant level set at P < 0.05. Logistic regression using R programming was utilized for these calculations.Univariate analysis was performed and rates of VTE (1.02% vs. 3.35%), 30-day mortality (0.25% vs. less than 5%), and 1-year mortality (1.42% vs. 5.43%) were higher in the COVID-19-positive group for THA patients (P < 0.001). For TKA patients, only 30-day mortality was significantly higher in the COVID-19-positive group (P = 0.034). Multivariate logistic regression revealed that a positive COVID-19 diagnosis within two weeks of surgery and a CCI score > 3 were significant predictors of postoperative complications and mortality for both TKA and THA.Patients with a positive COVID-19 diagnosis within 12 weeks of THA or TKA carried a significantly higher risk for postoperative complications and mortality. In addition, a CCI score > 3 is also a significant risk factor. These findings emphasize the importance of vigilant preoperative screening and risk stratification in the era of COVID-19.

  View details for DOI 10.1186/s42836-024-00275-x

  View details for PubMedID 39367443

  View details for PubMedCentralID PMC11452997

• Elevated Serum Alkaline Phosphatase is an Independent Predictor of Complications After Lumbar Spinal Fusion. World neurosurgery Chan, J. P., Lung, B., Donnelly, M., Hashmi, S. Z., Bhatia, N., Lee, Y. P. 2024; 188: e434-e440

  Abstract

  Alkaline phosphatase (ALP) is an enzyme which has been proven useful as a biomarker for bone turnover and inflammation. We hypothesized that high serum ALP levels are associated with increased complication rates following lumbar spinal fusion.Lumbar spinal fusion procedures from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database. Serum alkaline phosphatase levels were stratified into low <44 IU/L, normal 44-147 IU/L, and high >147 IU/L. A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor for complications.A total of 16,441 patients who underwent lumbar fusion procedures were included. Adjusted multivariate logistic regression analysis demonstrated that patients with a high serum ALP level had a significantly increased risk for developing septic shock (OR 4.68, 95% CI 1.83-11.97), pneumonia (OR 2.89, 95% CI 1.59-5.25), requiring a transfusion (OR 2.09, 95% CI 1.68-2.59), reoperation within 30 days (OR 1.68, 95% CI 1.12-2.52), readmission within 30 days (OR 1.60, 95% CI 1.16-2.21), increased length of stay (OR 1.87, 95% CI 1.49-2.36), and nonhome discharge (OR 2.18, 95% CI 1.80-2.66).Elevated serum ALP in patients undergoing lumbar fusion procedures is associated with increased risk for multiple in-hospital complications as well as higher rates of readmission and reoperation.

  View details for DOI 10.1016/j.wneu.2024.05.132

  View details for PubMedID 38810876

• Cervical Spine Surgery Following COVID-19 Infection: When is it Safe to Proceed? Clinical spine surgery Chan, J. P., Hoang, H., Wu, H. H., Park, D. Y., Lee, Y. P., Bhatia, N., Hashmi, S. Z. 2024; 37 (4): 155-163

  Abstract

  Retrospective.We utilized the NIH National COVID Cohort Collaborative (N3C) database to characterize the risk profile of patients undergoing spine surgery during multiple time windows following the COVID-19 infection.While the impact of COVID-19 on various organ systems is well documented, there is limited knowledge regarding its effect on perioperative complications following spine surgery or the optimal timing of surgery after an infection.We asked the National COVID Cohort Collaborative for patients who underwent cervical spine surgery. Patients were stratified into those with an initial documented COVID-19 infection within 3 time periods: 0-2 weeks, 2-6 weeks, or 6-12 weeks before surgery.A total of 29,449 patients who underwent anterior approach cervical spine surgery and 46,379 patients who underwent posterior approach cervical spine surgery were included. Patients who underwent surgery within 2 weeks of their COVID-19 diagnosis had a significantly increased risk for venous thromboembolic events, sepsis, 30-day mortality, and 1-year mortality, irrespective of the anterior or posterior approach. Among patients undergoing surgery between 2 and 6 weeks after COVID-19 infection, the 30-day mortality risk remained elevated in patients undergoing a posterior approach only. Patients undergoing surgery between 6 and 12 weeks from the date of the COVID-19 infection did not show significantly elevated rates of any complications analyzed.Patients undergoing either anterior or posterior cervical spine surgery within 2 weeks from the initial COVID-19 diagnosis are at increased risk for perioperative venous thromboembolic events, sepsis, and mortality. Elevated perioperative complication risk does not persist beyond 2 weeks, except for 30-day mortality in posterior approach surgeries. On the basis of these results, it may be warranted to postpone nonurgent spine surgeries for at least 2 weeks following a COVID-19 infection and advise patients of the increased perioperative complication risk when urgent surgery is required.

  View details for DOI 10.1097/BSD.0000000000001609

  View details for PubMedID 38648080

• Patient Likelihood to Repeat Surgery After Highly "Successful" Hand Procedures. Hand (New York, N.Y.) Chan, J. P., London, D. A., Franko, O. 2024; 19 (1): 180-184

  Abstract

  Outcomes for routine hand procedures, such as carpal tunnel release, trigger finger release, and first dorsal compartment release, are typically reported as "highly successful" with "infrequent complications" based on classic literature. No contemporary study has utilized a large prospective registry to assess patient willingness to repeat surgery. We utilized a prospective hand registry to evaluate the proportion of patients that would repeat surgery after common hand procedures.We utilized a prospective, hand surgery registry to collect postoperative patient likelihood to repeat surgery in patients undergoing surgery for 9 common hand procedures. All measures were reported at 12, 24, or 52 weeks. We analyzed the percentage of patients that would repeat the procedure for all diagnoses, as well as stratified by the most common 9 isolated diagnoses.At the time of analysis, 1905 patients met our inclusion criteria. The average percentage of patients across all procedures that would repeat surgery was 81.6%. When stratified by the most common 9 diagnoses the percentage of patients that would repeat surgery ranged from 51.9% (ulnar nerve surgery at the elbow) up to 87.5% (endoscopic carpal tunnel release).After undergoing routine hand procedures, a significant percentage of patients would choose not to repeat surgery. Hand surgeons can do better in setting clear and realistic preoperative expectations when counseling patients prior to even routine hand surgeries.

  View details for DOI 10.1177/15589447221109627

  View details for PubMedID 35815664

  View details for PubMedCentralID PMC10786117

• A temporal analysis of perioperative complications following COVID-19 infection in patients undergoing lumbar spinal fusion: When is it safe to proceed? North American Spine Society journal Chan, J. P., Hoang, H., Hashmi, S. Z., Lee, Y. P., Bhatia, N. N. 2023; 16: 100262

  Abstract

  COVID-19 has been shown to adversely affect multiple organ systems, yet little is known about its effect on perioperative complications after spine surgery or the optimal timing of surgery after an infection. We used the NIH National COVID Cohort Collaborative (N3C) database to characterize the risk profile in patients undergoing spine surgery during multiple time windows following COVID-19 infection.We queried the National COVID Cohort Collaborative, a database of 17.4 million persons with 6.9 million COVID-19 cases, for patients undergoing lumbar spinal fusion surgery. Patients were stratified into those with an initial documented COVID-19 infection within 3 time periods: 0 to 2 weeks, 2 to 6 weeks, or 6 to 12 weeks before surgery.A total of 60,541 patients who underwent lumbar spinal fusion procedures were included. Patients who underwent surgery within 2 weeks of their COVID-19 diagnosis had a significantly increased risk for venous thromboembolic events (OR 2.29, 95% CI 1.58-3.32), sepsis (OR 1.56, 95% CI 1.03-2.36), 30-day mortality (OR 5.55, 95% CI 3.53-8.71), and 1-year mortality (OR 2.70, 95% CI 1.91-3.82) compared with patients who were COVID negative during the same period. There was no significant difference in the rates of acute kidney injury or surgical site infection. Patients undergoing surgery between 2 and 6 weeks or between 6 and 12 weeks from the date of COVID-19 infection did not show significantly elevated rates of any complication analyzed.Patients undergoing lumbar spinal fusion within 2 weeks from initial COVID-19 diagnosis are at increased risk for perioperative venous thromboembolic events and sepsis. This effect does not persist beyond 2 weeks, however, so it may be warranted to postpone non-urgent spine surgeries for at least 2 weeks following a COVID-19 infection or to consider a more aggressive VTE chemoprophylaxis regimen for urgent surgery in COVID-19 patients.

  View details for DOI 10.1016/j.xnsj.2023.100262

  View details for PubMedID 37720242

  View details for PubMedCentralID PMC10504527

• Statistical Fragility of Randomized Controlled Trials Evaluating Platelet-Rich Plasma Use for Knee Osteoarthritis: A Systematic Review. Orthopaedic journal of sports medicine Chan, J. P., Vrla, M., Thompson, C., Trofa, D. P., Li, X., Wang, D., Parisien, R. L. 2023; 11 (8): 23259671231187894

  Abstract

  Numerous studies have been published on the use of platelet-rich plasma (PRP) for knee osteoarthritis (OA), with conflicting results.To determine the fragility index (FI) and fragility quotient (FQ) of randomized controlled trials (RCTs) that evaluated the use of PRP to treat knee OA.Systematic review.RCTs evaluating the efficacy of PRP injections for knee OA from 2000 to 2020 were included for analysis according to PRISMA guidelines. The FI was determined by calculating the number of outcome event reversals required to change the statistical significance. The associated FQ was determined by dividing the FI by the sample size.Our initial search resulted in 41,149 studies, of which 8 RCTs (678 patients, 72 outcome events) were included in the analysis. One study failed to report PRP formulation details, whereas 87.5% of studies reported using either leukocyte-rich or leukocyte-poor PRP. The platelet concentration was reported in 25% of the included trials. The overall FI of the 72 outcome events was 8.5. Accounting for sample size, the associated FQ was determined to be 0.14, suggesting that the reversal of 14% of outcome events was required to change outcome significance. There were 51 statistically significant outcomes, of which the FI and FQ were 12 and 0.164, respectively.Comprehensive fragility analysis suggested that the published literature evaluating the efficacy of PRP use for knee OA may lack statistical stability. We recommend the reporting of both an FI and FQ in addition to P value analysis to provide a clear and thorough understanding of the statistical integrity of studies reporting on PRP use for knee OA.

  View details for DOI 10.1177/23259671231187894

  View details for PubMedID 37655254

  View details for PubMedCentralID PMC10467394

• Hand Replantation With Dorsal Spanning Plate Following a Self-Inflicted Radiocarpal Amputation. Cureus Lai, W. C., Pham, C., Chan, J. P., Lung, B. E., Rafijah, G. H. 2023; 15 (3): e36656

  Abstract

  Upper extremity amputations represent a prime opportunity to restore function through replantation. There are a variety of options that treating surgeons use to protect neurovascular repairs and restore function including Kirschner wire fixation, external fixation, wrist arthrodesis, and proximal row carpectomy. Additionally, the dorsal spanning plate may be a valuable tool for protecting neurovascular repairs. Compared to temporary immobilization with Kirschner wire fixation, which has previously been described in conjunction with upper extremity replantation, dorsal spanning plates can be left in place for longer durations with a lower risk of loosening and loss of fixation and for preventing postoperative sabotage or repeat amputation of the replant by the patient. In this article, we describe a unique case of a patient with acute psychiatric illness that presented with a self-inflicted amputation through the radiocarpal joint and was initially treated with emergent replantation and application of a dorsal spanning plate to protect the neurovascular repair from patient sabotage and allow for early rehabilitation. We found the dorsal spanning plate to be an effective option in this complex clinical scenario. This case illustrates the utility of the dorsal spanning plate in protecting complex neurovascular repairs in the setting of severe skeletal and psychiatric instability.

  View details for DOI 10.7759/cureus.36656

  View details for PubMedID 37102009

  View details for PubMedCentralID PMC10123377

• Return to Work and Sport After Distal Femoral Osteotomy: A Systematic Review. Sports health Bassi, J. S., Chan, J. P., Johnston, T., Wang, D. 2022; 14 (5): 681-686

  Abstract

  Distal femoral osteotomy (DFO) is a joint preservation procedure that corrects genu valgum deformities and patellofemoral maltracking, thereby restoring kinematics and unloading contact pressures in the lateral tibiofemoral and patellofemoral compartments.To evaluate the rates of return to work (RTW) and return to sport (RTS) after DFO for valgus malalignment and lateral compartment osteoarthritis through a systematic review of the literature.A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted on the PubMed, Cochrane, and Embase databases.The search terms femoral osteotomy AND (sports OR work) were used. Studies in which patients underwent concomitant total knee arthroplasty were excluded.Systematic review.Level 4 (systematic review of level 4 studies).Data included the number of patients, age, gender, laterality of operation, time to follow-up, rate of RTW and RTS, time to RTS, activity level on return, and activity level scores (Tegner, Marx, Lysholm, and the International Knee Documentation Committee). Risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.Seven articles with 194 patients were included. The average age ranged from 19 to 49 years with a mean postoperative follow-up range of 36 to 90 months. RTW data were available for 125 patients, of whom 42.1% to 91.3% returned by final follow-up. Data on RTS were available for 149 patients, of whom 70% to 100% returned at a range of 8.3 to 16.9 months postoperatively, and 41.6% to 100% returned to the same or greater level of sports activity. The Tegner and Marx activity level scores ranged from 3 to 4 and from 5 to 11, respectively, at final follow-up.Patients treated with DFO reported high rates of RTW and RTS, with most patients being able to return to recreational sport after surgery.

  View details for DOI 10.1177/19417381211041072

  View details for PubMedID 34486439

  View details for PubMedCentralID PMC9460096

• Preoperative hypoalbuminemia and dialysis increase morbidity/mortality after spine surgery for primary pyogenic spinal infections (ACS-NSQIP Study). Surgical neurology international Camino-Willhuber, G., Franklin, A., Rosecrance, K., Oyadomari, S., Chan, J., Holc, F., Hashmi, S., Oh, M., Bhatia, N., Emmerich, J., Lee, Y. P. 2022; 13: 193

  Abstract

  We analyzed the role of hypoalbuminemia, dialysis, and other risk factors that increase morbidity/ mortality following surgery for primary pyogenic spinal infections (PSIs). The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) that included 627 patients was utilized as our database.Primary spinal surgery for spondylodiscitis was evaluated in a ACS-NSQIP database involving 627 patients between 2010 and 2019. Outcome assessment included evaluation of 30-day postoperative morbidity, and mortality rates.Within 30 postoperative days, complications occurred in 14.6% (92/627) of patients; 59 (9.4%) required readmission, and 39 (6.2%) required additional surgery. The most common complications were: wound infections, pneumonia, septic shock, and death (1.8%). Hypoalbuminemia (i.e., significantly associated with unplanned readmission and reoperation), and dialysis were the two major risk factors contributing to increased perioperative morbidity and mortality.Among 627 ACS-NSQIP patients undergoing primary surgery for PSIs, hypoalbuminemia and dialysis were associated with higher risks of major perioperative morbidity (i.e., within 30 postoperative days - mostly readmissions and reoperations) and mortality.

  View details for DOI 10.25259/SNI_330_2022

  View details for PubMedID 35673646

  View details for PubMedCentralID PMC9168331

• Human motor endplate remodeling after traumatic nerve injury. Journal of neurosurgery Gupta, R., Chan, J. P., Uong, J., Palispis, W. A., Wright, D. J., Shah, S. B., Ward, S. R., Lee, T. Q., Steward, O. 2021; 135 (1): 220-227

  Abstract

  Current management of traumatic peripheral nerve injuries is variable with operative decisions based on assumptions that irreversible degeneration of the human motor endplate (MEP) follows prolonged denervation and precludes reinnervation. However, the mechanism and time course of MEP changes after human peripheral nerve injury have not been investigated. Consequently, there are no objective measures by which to determine the probability of spontaneous recovery and the optimal timing of surgical intervention. To improve guidance for such decisions, the aim of this study was to characterize morphological changes at the human MEP following traumatic nerve injury.A prospective cohort (here analyzed retrospectively) of 18 patients with traumatic brachial plexus and axillary nerve injuries underwent biopsy of denervated muscles from the upper extremity from 3 days to 6 years after injury. Muscle specimens were processed for H & E staining and immunohistochemistry, with visualization via confocal and two-photon excitation microscopy.Immunohistochemical analysis demonstrated varying degrees of fragmentation and acetylcholine receptor dispersion in denervated muscles. Comparison of denervated muscles at different times postinjury revealed progressively increasing degeneration. Linear regression analysis of 3D reconstructions revealed significant linear decreases in MEP volume (R = -0.92, R2 = 0.85, p = 0.001) and surface area (R = -0.75, R2 = 0.56, p = 0.032) as deltoid muscle denervation time increased. Surprisingly, innervated and structurally intact MEPs persisted in denervated muscle specimens from multiple patients 6 or more months after nerve injury, including 2 patients who had presented > 3 years after nerve injury.This study details novel and critically important data about the morphology and temporal sequence of events involved in human MEP degradation after traumatic nerve injuries. Surprisingly, human MEPs not only persisted, but also retained their structures beyond the assumed 6-month window for therapeutic surgical intervention based on previous clinical studies. Preoperative muscle biopsy in patients being considered for nerve transfer may be a useful prognostic tool to determine MEP viability in denervated muscle, with surviving MEPs also being targets for adjuvant therapy.

  View details for DOI 10.3171/2020.8.JNS201461

  View details for PubMedID 32947259

• Blood Coagulation Factor Fibrinogen in Tumor Pathogenesis of Central Nervous System B-Cell Lymphoma. The American journal of pathology Chan, J. P., Merlini, M., Gao, H. X., Mendiola, A. S., Akassoglou, K., Rubenstein, J. L., Ryu, J. K. 2021; 191 (3): 575-583

  Abstract

  Central nervous system (CNS) lymphoma is an extranodal non-Hodgkin B-cell lymphoma characterized by malignant lymph tissue arising in the brain or spinal cord, associated with inflammation and blood-brain barrier (BBB) disruption. Although BBB disruption is known to occur in patients with CNS lymphoma, a direct link between these two has not been shown. Herein, abundant deposition of the blood coagulation protein fibrinogen around B-cell lymphoma was detected in CNS lymphoma patients and in the CNS parenchyma in an orthotopic mouse model. Functional enrichment analysis of unbiased cerebrospinal fluid proteomics of CNS B-cell lymphoma patients showed that coagulation protein networks were highly connected with tumor-associated biological signaling pathways. In vivo two-photon imaging demonstrated that lymphoma growth was associated with BBB disruption, and in vitro experiments identified a role for fibrinogen in promoting lymphoma cell adhesion. Overall, these results identify perivascular lymphoma clustering at sites of fibrinogen deposition, and suggest that fibrinogen may be a target for pharmacologic intervention in metastatic B-cell lymphoma associated with BBB disruption.

  View details for DOI 10.1016/j.ajpath.2020.12.010

  View details for PubMedID 33608067

  View details for PubMedCentralID PMC7919853

• Ergonomics in Dermatologic Surgery: Lessons Learned Across Related Specialties and Opportunities for Improvement. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] Chan, J., Kim, D. J., Kassira-Carley, S., Rotunda, A. M., Lee, P. K. 2020; 46 (6): 763-772

  Abstract

  As the practice of dermatology becomes increasingly procedurally based, there is a concordant rise in musculoskeletal injury (MSI) risk. Dermatologic surgeons are most susceptible and, although the majority suffer from MSI, few have received any formal ergonomics training. This stems from a lack of awareness of this troubling trend and a paucity of research and education on the ergonomics of dermatologic surgery.To highlight pertinent ergonomics principles and strategies from other specialties that could be translated into dermatology, and to synthesize general recommendations aimed at reducing MSI among dermatologic surgeons.A comprehensive search of the PubMed and Cochrane Reviews databases from 1975 to 2019 was conducted, using a combination of ergonomics-related search terms, generating 6 publications from the dermatology literature and 58 from the fields of dentistry, medicine, and select surgical subspecialties.This multidisciplinary approach yielded multiple interventions that could be applied directly (i.e., adequate lighting, adjustable operating tables, and surgical seat heights) or indirectly pending further investigation into their feasibility (i.e., video displays of the surgical field to allow neutral head and neck postures).Although much can be learned from decades of prior ergonomics research from other specialties, considerations that are unique to dermatology remain and must be addressed with specialty-specific research.

  View details for DOI 10.1097/DSS.0000000000002295

  View details for PubMedID 31876576

• Examination of the human motor endplate after brachial plexus injury with two-photon microscopy. Muscle & nerve Chan, J. P., Clune, J., Shah, S. B., Ward, S. R., Kocsis, J. D., Mozaffar, T., Steward, O., Gupta, R. 2020; 61 (3): 390-395

  Abstract

  After traumatic nerve injury, neuromuscular junction remodeling plays a key role in determining functional outcomes. Immunohistochemical analyses of denervated muscle biopsies may provide valuable prognostic data regarding clinical outcomes to supplement electrodiagnostic studies.We performed biopsies on nonfunctioning deltoid muscles in two patients after gunshot wounds and visualized the neuromuscular junctions using two-photon microscopy with immunohistochemistry.Although the nerves in both patients showed evidence of acute Wallerian degeneration, some of the motor endplates were intact but exhibited significantly decreased surface area and volume. Both patients exhibited substantial recovery of motor function over several weeks postinjury.Two-photon microscopic assessment of neuromuscular junction integrity and motor endplate morphometry in muscle biopsies provided evidence of partial sparing of muscle innervation. This finding supported the clinical judgment that eventual recovery would occur. With further study, this technique may help to guide operative decisionmaking after traumatic nerve injuries.

  View details for DOI 10.1002/mus.26778

  View details for PubMedID 31820462

• Lessons From Leprosy: Peripheral Neuropathies and Deformities in Chronic Demyelinating Diseases. The Journal of hand surgery Chan, J. P., Uong, J., Nassiri, N., Gupta, R. 2019; 44 (5): 411-415

  Abstract

  In light of the World Health Organization's push to accelerate progress toward a leprosy-free world by 2020, it is fitting to look back on the evolution of progress in treating lepromatous neuropathy and limb deformities. To date, no surgeon has had as great an impact on the understanding and treatment of this disease as Dr Paul Brand. Before Dr Brand's accomplishments, few surgeons participated in the management of the deformed leprous patient. By challenging conventional beliefs, Dr Brand revealed that many of the deformities associated with leprosy were in fact caused by nerve damage and subsequent limb anesthesia. His pioneering work centered on tendon transfers to provide hand and foot mobility to leprous patients, revolutionizing the surgical management of this patient population and restoring functionality to the lives of otherwise stigmatized and functionally handicapped individuals. In the process, he provided us with the surgical principles and techniques that we still apply today. Because of its predilection for the peripheral nervous system, leprosy also provides an excellent opportunity to investigate mechanisms of demyelination and chronic nerve degeneration in nonacute peripheral neuropathies. Processes underlying demyelination of infectious, traumatic, and genetic etiologies overlap and precede the onset of acute neuronal derangement. Glial pathology has been shown to be a common pathological element in leprosy, Charcot-Marie-Tooth type I, multiple sclerosis, and chronic nerve compression injury. The aim of this article is to provide an overview of lepromatous neuropathy with its subsequent deformities as it relates to the pathophysiology, surgical management, and potential therapeutic targets of other modern peripheral neuropathies.

  View details for DOI 10.1016/j.jhsa.2018.07.007

  View details for PubMedID 30177357

• Fibrin-targeting immunotherapy protects against neuroinflammation and neurodegeneration. Nature immunology Ryu, J. K., Rafalski, V. A., Meyer-Franke, A., Adams, R. A., Poda, S. B., Rios Coronado, P. E., Pedersen, L. Ø., Menon, V., Baeten, K. M., Sikorski, S. L., Bedard, C., Hanspers, K., Bardehle, S., Mendiola, A. S., Davalos, D., Machado, M. R., Chan, J. P., Plastira, I., Petersen, M. A., Pfaff, S. J., Ang, K. K., Hallenbeck, K. K., Syme, C., Hakozaki, H., Ellisman, M. H., Swanson, R. A., Zamvil, S. S., Arkin, M. R., Zorn, S. H., Pico, A. R., Mucke, L., Freedman, S. B., Stavenhagen, J. B., Nelson, R. B., Akassoglou, K. 2018; 19 (11): 1212-1223

  Abstract

  Activation of innate immunity and deposition of blood-derived fibrin in the central nervous system (CNS) occur in autoimmune and neurodegenerative diseases, including multiple sclerosis (MS) and Alzheimer's disease (AD). However, the mechanisms that link disruption of the blood-brain barrier (BBB) to neurodegeneration are poorly understood, and exploration of fibrin as a therapeutic target has been limited by its beneficial clotting functions. Here we report the generation of monoclonal antibody 5B8, targeted against the cryptic fibrin epitope γ377-395, to selectively inhibit fibrin-induced inflammation and oxidative stress without interfering with clotting. 5B8 suppressed fibrin-induced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and the expression of proinflammatory genes. In animal models of MS and AD, 5B8 entered the CNS and bound to parenchymal fibrin, and its therapeutic administration reduced the activation of innate immunity and neurodegeneration. Thus, fibrin-targeting immunotherapy inhibited autoimmunity- and amyloid-driven neurotoxicity and might have clinical benefit without globally suppressing innate immunity or interfering with coagulation in diverse neurological diseases.

  View details for DOI 10.1038/s41590-018-0232-x

  View details for PubMedID 30323343

  View details for PubMedCentralID PMC6317891

• p75 Neurotrophin Receptor Regulates Energy Balance in Obesity. Cell reports Baeza-Raja, B., Sachs, B. D., Li, P., Christian, F., Vagena, E., Davalos, D., Le Moan, N., Ryu, J. K., Sikorski, S. L., Chan, J. P., Scadeng, M., Taylor, S. S., Houslay, M. D., Baillie, G. S., Saltiel, A. R., Olefsky, J. M., Akassoglou, K. 2016; 14 (2): 255-68

  Abstract

  Obesity and metabolic syndrome reflect the dysregulation of molecular pathways that control energy homeostasis. Here, we show that the p75 neurotrophin receptor (p75(NTR)) controls energy expenditure in obese mice on a high-fat diet (HFD). Despite no changes in food intake, p75(NTR)-null mice were protected from HFD-induced obesity and remained lean as a result of increased energy expenditure without developing insulin resistance or liver steatosis. p75(NTR) directly interacts with the catalytic subunit of protein kinase A (PKA) and regulates cAMP signaling in adipocytes, leading to decreased lipolysis and thermogenesis. Adipocyte-specific depletion of p75(NTR) or transplantation of p75(NTR)-null white adipose tissue (WAT) into wild-type mice fed a HFD protected against weight gain and insulin resistance. Our results reveal that signaling from p75(NTR) to cAMP/PKA regulates energy balance and suggest that non-CNS neurotrophin receptor signaling could be a target for treating obesity and the metabolic syndrome.

  View details for DOI 10.1016/j.celrep.2015.12.028

  View details for PubMedID 26748707

  View details for PubMedCentralID PMC4831919

• Blood coagulation protein fibrinogen promotes autoimmunity and demyelination via chemokine release and antigen presentation NATURE COMMUNICATIONS Ryu, J., Petersen, M. A., Murray, S. G., Baeten, K. M., Meyer-Franke, A., Chan, J. P., Vagena, E., Bedard, C., Machado, M. R., Coronado, P., Prod'homme, T., Charo, I. F., Lassmann, H., Degen, J. L., Zamvil, S. S., Akassoglou, K. 2015; 6: 8164

  Abstract

  Autoimmunity and macrophage recruitment into the central nervous system (CNS) are critical determinants of neuroinflammatory diseases. However, the mechanisms that drive immunological responses targeted to the CNS remain largely unknown. Here we show that fibrinogen, a central blood coagulation protein deposited in the CNS after blood-brain barrier disruption, induces encephalitogenic adaptive immune responses and peripheral macrophage recruitment into the CNS leading to demyelination. Fibrinogen stimulates a unique transcriptional signature in CD11b(+) antigen-presenting cells inducing the recruitment and local CNS activation of myelin antigen-specific Th1 cells. Fibrinogen depletion reduces Th1 cells in the multiple sclerosis model, experimental autoimmune encephalomyelitis. Major histocompatibility complex (MHC) II-dependent antigen presentation, CXCL10- and CCL2-mediated recruitment of T cells and macrophages, respectively, are required for fibrinogen-induced encephalomyelitis. Inhibition of the fibrinogen receptor CD11b/CD18 protects from all immune and neuropathologic effects. Our results show that the final product of the coagulation cascade is a key determinant of CNS autoimmunity.

  View details for DOI 10.1038/ncomms9164

  View details for Web of Science ID 000363016800002

  View details for PubMedID 26353940

  View details for PubMedCentralID PMC4579523

• Nuclear pore complex remodeling by p75(NTR) cleavage controls TGF-ß signaling and astrocyte functions. Nature neuroscience Schachtrup, C., Ryu, J. K., Mammadzada, K., Khan, A. S., Carlton, P. M., Perez, A., Christian, F., Le Moan, N., Vagena, E., Baeza-Raja, B., Rafalski, V., Chan, J. P., Nitschke, R., Houslay, M. D., Ellisman, M. H., Wyss-Coray, T., Palop, J. J., Akassoglou, K. 2015; 18 (8): 1077-1080

  Abstract

  Astrocytes modulate neuronal activity and inhibit regeneration. We show that cleaved p75 neurotrophin receptor (p75(NTR)) is a component of the nuclear pore complex (NPC) required for glial scar formation and reduced gamma oscillations in mice via regulation of transforming growth factor (TGF)-β signaling. Cleaved p75(NTR) interacts with nucleoporins to promote Smad2 nucleocytoplasmic shuttling. Thus, NPC remodeling by regulated intramembrane cleavage of p75(NTR) controls astrocyte-neuronal communication in response to profibrotic factors.

  View details for DOI 10.1038/nn.4054

  View details for PubMedID 26120963