Search

OBJECTIVE The US-based Spinal Laminectomy versus Instrumented Pedicle Screw (SLIP) trial reported improvement in disability following laminectomy with fusion versus laminectomy alone for patients with lumbar spondylolisthesis. Despite using similar methods, a concurrent Swedish trial investigating the same question did not reach the same conclusion. The authors performed a simulation-based analysis to elucidate potential causes of these divergent results. METHODS The mean and standard deviation of the preoperative and 2-year postoperative Oswestry Disability Index (ODI) scores for each study group (laminectomy with fusion and laminectomy alone) were collected from the spondylolisthesis stratum of the Swedish trial and used to create a MATLAB simulator using linear transformations to predict postoperative ODI distributions. Applying this simulator to both varied and published preoperative ODI distributions from the SLIP trial, the authors simulated the results of the US-based trial using treatment effects from the Swedish study and compared simulated US results to those published in the SLIP trial. RESULTS Simulated US results showed that as preoperative disability increased, the difference in postoperative ODI scores grew between treatment groups and increasingly favored laminectomy alone (p < 0.0001). In 100 simulations of a similarly sized US trial, the average mean change in ODI scores postoperatively was significantly higher than was published for laminectomy alone in the SLIP trial (−21.3 vs −17.9), whereas it was significantly lower than published for fusion (−16.9 vs −26.3). CONCLUSIONS The expected benefit of surgical treatments for spondylolisthesis varied according to preoperative disability. Adapting Swedish-estimated treatment effects to the US context mildly overapproximated the improvement in postoperative disability scores for laminectomy, but more severely underapproximated the improvement reported for laminectomy and fusion in the SLIP trial. The observed heterogeneity between these studies is influenced more by patient response to fusion than response to laminectomy. This analysis paves the way for future studies on the impact of preoperative treatment group heterogeneity, differences in surgical methods, and empirical design on reported clinical benefits. Although bayesian reanalysis of published randomized controlled trial data is susceptible to biases that typically limit post hoc analyses, the authors’ method offers a simple and cost-effective approach to improve the understanding of published clinical trial results and their implications for future studies.

Traumatic proximal tibiofibular joint dislocations occur infrequently and are typically the result of high-energy trauma. These injuries can be a marker of limb injury severity because patients often sustain vascular injury and are at high risk of amputation. The purpose of this study was to present a systematic review of traumatic proximal tibiofibular joint dislocations and compare rates of associated injuries with a retrospective series of patients at a level 1 trauma center. The secondary objective was to report rates and clinical predictors of limb amputation.A systematic review was conducted, identifying three studies meeting eligibility criteria. A retrospective chart review was conducted identifying 17 skeletally mature patients with proximal tibiofibular dislocation treated from January 2010 to February 2021. A chart review extracted patient demographics, fracture patterns, open fracture, preoprative and postoperative peroneal nerve injury, vascular injury, and amputation. Binary logistic regression analysis was used to identify clinical predictors of outcomes.Sixteen of 17 proximal tibiofibular injuries (94.1%) were associated with fracture, most commonly tibial shaft (n = 11, 68.75%). Twelve of 17 fractures (76.5%) were open. Five vascular injuries (29.4%) occurred requiring surgical intervention. Seven (41.2%) preoperative peroneal nerve deficits were noted; six had persistent deficits postoperatively or underwent amputation (average follow-up 31.3 ± 32.6 months). Two patients in the sample without preoperative peroneal nerve deficits were noted to exhibit them after fixation. Eight patients (47%) underwent an amputation, 7 (87.5%) of whom had an open fracture and 4 (50%) of whom had documented vascular injury.Traumatic proximal tibiofibular fractures indicate severe injury to the lower extremity with high risk for nerve injury and possible amputation. Patients who present with vascular injury and open fracture in association with proximal tibiofibular joint disruption may be at elevated risk of amputation.

Study Design Retrospective comparative study. Objectives This study compares supine vs bending flexibility radiographs and evaluates their ability to predict residual postoperative lumbar curvature after selective thoracic fusion for Lenke 1 and 2 curves across different lumbar modifiers (A, B, and C) in adolescent idiopathic scoliosis (AIS). Methods This was a retrospective review of AIS Lenke 1 and 2 patients who underwent posterior fusion. All patients had preoperative flexibility radiographs including side-bending and supine posteroanterior (PA) films, in addition to pre- and post-operative standing PA and lateral radiographs. We used SurgiMap 2.0 software for all radiographic measurements. Pearson correlations and linear regression models were developed in SAS. Results A total of 86 patients were included mean age 14.9 years and follow-up 72.3 months. Preoperative supine lumbar Cobb angle and preoperative side-bending Cobb angles had similar, positive correlations with postoperative lumbar Cobb angle, r = .55 ( P < .001) and r = .54 ( P < .001), respectively. Three regression models were built to predict postoperative lumbar Cobb angles from preoperative information: Model S (R2 = .39) uses preoperative supine lumbar curve; Model B (R2 = .44) uses preoperative side-bending lumbar curve; Model SB (R2 = .49) uses both preoperative supine and side-bending lumbar curves. Model S and B performed just as well as Model SB. Conclusion Either supine or side-bending radiographs alone may be used to estimate mean residual postoperative lumbar curvature after selective posterior thoracic fusion, but little is to be gained by taking both supine and side-bending radiographs.