Faculty Bibliography

BackgroundThe use of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) instrumentation in spinal surgery has emerged as an alternative to traditional titanium-based implants in recent years. This study aims to evaluate the use and performance of carbon fiber instrumentation in patients with primary spinal tumors focusing on adverse event (AE) risk, overall survival and oncologic outcomes.MethodsData were collected from the AO Spine Primary Tumor Research and Outcomes Network (PTRON), a multicenter international registry. The primary endpoint was the incidence of AEs, while secondary endpoints included the risk of developing at least one AE, overall survival, local tumor control, and disease progression.ResultsA total of 359 patients enrolled in the PTRON registry met the inclusion criteria and were included in the study. Among them, 84 receiving carbon fiber implants (23%), 243 titanium implants (68%), and 32 a combination of both (9%). Median follow-up times were 1.9 years (IQR: 0.4-3.0), 1.3 years (IQR: 0.5-2.4) and 1.1 years (IQR: 0.5-1.7), in the carbon fiber, titanium and combination groups, respectively. The estimated risk of having at least one postoperative AE, including construct failures with and without loss of correction, wound infection (deep or superficial), non-union and wound dehiscence, was statistically comparable between patients receiving carbon fiber, titanium or a combination of both carbon fiber and titanium implants (P > 0.05). Kaplan-Meier survival analyses and multivariable Cox proportional hazards models showed no significant differences in overall survival, recurrence-free survival, or progression-free survival between the implant groups.ConclusionCarbon fiber spinal implants demonstrate a comparable safety and oncologic profile to traditional titanium implants while allowing for improved tumor surveillance and easier radiation delivery.

OBJECTIVE:Spinal meningiomas (SMs) are common primary spinal tumors for which surgery is considered the first-line treatment when safe and feasible. The ability to extrapolate the tumor grade from preoperative imaging may significantly inform early patient expectation-setting regarding recurrence. Building on radiomics studies in cranial meningiomas, the authors aimed to construct a benchmark radiomics model to preoperatively identify the histological grade of SMs. METHODS:Institutional surgical records from May 2012 to November 2025 were queried for pathology-confirmed meningiomas below the foramen magnum, with preoperative contrast-enhanced imaging available for segmentation. SMs were classified as low-grade (WHO grade 1) and high-grade (WHO grade 2 tumors and grade 1 tumors with atypia). Tumors were manually segmented, and features were extracted using the PyRadiomics software package. An ensemble model of k-nearest neighbors, random forest, and support vector machine classifiers was trained using nested cross-validation on a subset of 10 features to differentiate tumor grades. Clinical data for the cohort were also extracted, and disease control in an adjunctive clinical series was assessed. RESULTS:Seventy-four patients were included in radiomics analysis, with an area under the receiver operating characteristic curve of 0.879 and a mean F1 score of 0.748. The model's top 5 features were all texture features that differed significantly (p < 0.05) across low- and high-grade SMs. These included measures of tumor textural and contrast-enhancement heterogeneity, with overlap with features reported in radiomics models for histological grading of intracranial meningiomas. Fifty-five patients with a median radiographic follow-up of 22.2 (range 1.9-86.4) months remained for clinical analysis after exclusion of patients with less than 1 month of follow-up and syndromic meningiomas. Four recurrences occurred at a median of 20.8 (range 1.8-41.8) months. High-grade tumor pathology did not significantly impact progression-free survival (p = 0.682, log-rank test; Cox regression high vs low grade hazard ratio [HR] 0.62, 95% CI 0.06-6.11, p = 0.685). Subtotal resection was associated with poorer progression-free survival than gross-total resection (p = 0.004, log-rank test; Cox regression subtotal vs gross-total resection HR 10.62, 95% CI 1.46-77.05, p = 0.019). These findings remain contextualized within a relatively limited follow-up window and small recurrence event count, suggesting a need to characterize the interplay between tumor grade and extent of resection as drivers of local disease control in SMs. CONCLUSIONS:A preoperative radiomics model can stratify high-grade SMs using open-source tools applied to single-institution data.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Anterior lumbar interbody fusion (ALIF) is an important technique offering biomechanical advantages including improved disk height restoration, correction of sagittal and coronal imbalance, and improved fusion. Although generally safe, vascular injury remains a serious complication. Specific vascular injury mechanisms, management, and outcomes are insufficiently reported. We seek to better characterize the incidence, mechanism, management, and sequelae of intraoperative vascular injuries during ALIF. METHODS:We performed a retrospective single-center study of adult patients undergoing ALIF between 2018 and 2022. All exposures were performed by a vascular surgeon. Data analyzed included patient demographics, operative characteristics, and vascular complications (classified as major or minor). The primary outcomes were the incidence of vascular injury and postoperative venous thromboembolism (VTE). Statistical analyses included χ2 testing and logistic regression. RESULTS:Of 418 patients, 26 (6.2%) sustained intraoperative vascular injuries, with 4 (1.0%) classified as major. Injuries were predominantly venous (n = 25), most frequently involving the left common iliac vein during L4-L5 exposure. One arterial dissection required stenting. Postoperative VTE occurred in 11 patients (2.6%); notably, 45.5% of these patients had sustained an intraoperative vascular injury. Vascular injury was a strong independent predictor of VTE (odds ratio [OR]: 15.9; P < .001; 95% CI: 4.3-58.8). The number of levels fused was significantly associated with both vascular injury (OR: 1.76; P = .007; 95% CI: 1.16-2.66) and VTE (OR: 1.91; P = .031; 95% CI: 1.03-3.42). No association was found between vascular complications and previous abdominal surgery, body mass index, revision surgery, age older than 50, spinal deformity, or sex. There was 0% perioperative mortality. CONCLUSION/CONCLUSIONS:Vascular complications during ALIF are infrequent but significantly elevate the risk of postoperative VTE. Injuries cluster at the L4-L5 level and often involve the left common iliac vein. Preoperative planning, careful surgical technique, and experienced vascular access support are critical to minimizing complications.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Intradural extramedullary spinal tumors (IDEMs) are ideally managed with gross total resection (GTR) for optimal local disease control in the absence of established adjuvant regimens. In this retrospective cohort study, we investigated the utility of morphology-based analysis of optimal IDEM resection quality compared with current linear measurement benchmarks. METHODS:Tumors were manually segmented from preoperative contrast-enhanced MRI. Morphological features of sphericity, elongation, and volume were extracted from masks, along with manual anteroposterior, craniocaudal, and transverse linear measurements. Optimal resection was defined as Simpson Grade 1 or 2 for meningiomas or en bloc GTR for myxopapillary ependymomas (MPEs) and was predicted for dorsal and ventral spinal meningiomas plus conus and nonconus MPEs. RESULTS:We identified 103 tumors, including 71 meningiomas and 32 MPEs. Linear measurement did not reliably predict optimal resection across anatomic subtypes of meningiomas or MPEs (all P > .05). Instead, optimal resection was determined by higher sphericity across meningiomas and, specifically, dorsal meningiomas (optimal resection median 0.80 (IQR: 0.77-0.82) vs suboptimal 0.76 (0.72-0.77), P = .027). Shape features were not predictive in ventral meningiomas. En bloc GTR was limited to nonconus MPEs, in which sphericity again emerged as a predictor (0.74 (0.69-0.77) for en bloc vs 0.68 (0.64-0.72) for piecemeal, P = .047), likely reflecting resectability for encapsulated tumors. After excluding patients with <1 year of surveillance to determine nonrecurrence, 62 patients without genetic syndromes remained for recurrence analysis with a median follow-up of 36.1 months. Optimal resection was associated with significantly lower recurrence (optimal 8.6% vs suboptimal 29.6%, P = .045). This protective effect remained, although statistically insignificant after adjusting for adjuvant radiation and tumor grade (recurrence odds ratio = 0.22, 95% CI: 0.04-1.07, P = .077). CONCLUSION/CONCLUSIONS:IDEM tumor morphology is predictive of optimal resection for dorsal meningiomas and nonconus MPEs, whereas linear measurements offer less consistent predictive value. Morphological assessment is feasible with standard MRI and may be further automated.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Multiple-choice questions are the primary assessment format for neurosurgical board certification. Creating high-quality examination questions requires significant expert time and resources. The goal of this study was to develop an automated system to generate board-style neurosurgical multiple-choice questions using state-of-the-art vision-language models and compare their quality with authentic self-assessment questions. METHODS:articles. We generated 89 587 synthetic questions: 45 689 with GPT-4o and 43 898 with Claude. Each question was associated with a single image extracted from the articles' figures. We evaluated the quality of synthetic questions through 5 surveys comparing 20 synthetic questions (10 from each model) with 10 authentic questions from the Self-Assessment for Neurological Surgeons (SANS) question bank. Each survey was completed by a neurosurgery resident and an attending who guessed the source [human vs artificial intelligence (AI)-generated] and rated suitability for board examination use. We also evaluated the question-answering performance of the generalist GPT-4o and the specialized CNS-Obsidian. RESULTS:). CONCLUSION/CONCLUSIONS:Although quality gaps exist between AI-generated and human-created neurosurgical board examination questions, our approach demonstrates the potential of vision-language models to augment assessment development in specialized medical fields, reducing the burden on examination boards and credentialing organizations.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The objective of this study was to compare sociodemographic factors, presenting characteristics, and outcomes between cohorts of patients receiving surgery for spinal metastases at 2 neighboring institutions, 1 private and 1 public, affiliated with a single major academic medical center in a large metropolitan area. METHODS:This analysis included all patients who underwent decompressive surgery for extradural spinal metastases. Sociodemographic factors, treatment characteristics, and outcomes were compared between those treated at a private hospital and a neighboring public hospital using Rao-Scott χ 2 tests for categorical variables, Student t tests for continuous variables, and the Kaplan-Meier product-limit method for overall survival and progression-free survival. RESULTS:Compared with those treated at our private hospital, patients treated at our public hospital were more often younger ( P = .005), of Black or Hispanic race (72.6% vs 19%, P < .001), and uninsured (16% vs 5.6%, P = .005). They more frequently presented with epidural spinal cord compression grade 3 (76% vs 56.8%, P = .027), were nonambulatory before surgery (56.9% vs 13.5%, P < .001), and had increased neurological impairment as denoted by American Spinal Injury Association Impairment Scale grades of A, B, or C (39.2% vs 7.5%). Patients treated at our public hospital had shorter median follow-up time (92 vs 302.5 days, P = .004). Multivariate analysis did not reveal a significant difference in overall survival or progression-free survival between hospitals, instead demonstrating associations with primary tumor histology and number of spinal metastases ( P < .05). CONCLUSION/CONCLUSIONS:There were substantial disparities in sociodemographic factors, presenting local disease burden, and postoperative neurological outcome but no difference in survival outcome, between patients treated at our public and private hospitals. These findings underscore the need for more equitable screening, surveillance, and referral structures.

Study DesignSystematic review and meta-analysis.ObjectivesWe sought to evaluate the association between pre-treatment symptom duration and outcomes in patients undergoing radiotherapy (RT)/surgery for metastatic epidural spinal cord compression (MESCC).MethodsA systematic review included publications evaluating the association between pre-treatment symptom duration and outcomes after RT/surgery in adults with MESCC. Primary exposure was pre-treatment symptom duration. Outcomes were motor-recovery, ambulation, survival and local control. Pooled-effect-estimates were calculated.Results Of 4639 studies, 37 met the inclusion criteria (26-RT,11-surgery). RT: All studies defined symptom duration as time from motor-weakness onset to RT. Longer symptom duration was associated with improved motor-recovery (Pooled-effect-estimate=2.08, 95%CI:1.68-2.58,p<0.001) and decreased mortality-risk (improved-survival)((Pooled-effect-estimate=0.72, 95%CI:0.69-0.76,p<0.001). Although longer symptom duration was consistently associated with better ambulation and lower local recurrence, few studies precluded meta-analysis. Surgery: Symptom duration was defined as time from neurological-deficit onset to surgery in 7/11 studies; three-studies used ambulatory status, and one-study used both. Longer symptom duration was associated with increased risk-of-death (worse-survival)(Pooled-effect-estimate=1.28, 95%CI:0.54-3.03,p=0.575), though statistically insignificantly. Meta-analysis for motor-recovery wasn't feasible, but most studies found longer symptom duration worsened motor-recovery, while ambulation findings were inconsistent.ConclusionSymptom duration was associated with differing outcome patterns by treatment modality. In RT cohorts, longer symptom duration was associated with improved survival and motor recovery. In surgical cohorts, it trended toward worse survival, though this did not reach statistical significance. Most surgical studies suggested an inverse association between symptom duration and motor recovery. These findings are exploratory, and should be interpreted in context of treatment selection-bias and between-cohort heterogeneity.

PURPOSE/OBJECTIVE:Spinal metastases may progress to debilitating pain, spinal instability, and neurological deficits. Timely referral is essential, yet delays are common because patients often first present to non-spine clinicians where red flags rarely expedite referral and guidelines primarily target spine specialists. We aimed to develop a staging-based referral tool to support non-spine clinicians in recognizing progression and guiding referral urgency. METHODS:We defined the Spinal Metastasis Staging (SMS) system as four stages: SMS I, asymptomatic; SMS II, inflammatory pain; SMS III, mechanical pain and/or spinal instability; and SMS IV, neurological deficits and/or high-grade spinal cord compression. Stages were translated into a referral algorithm organized by urgency and presented as a pocket map. The tool was refined through regional and international multidisciplinary expert panels, and feasibility was evaluated in an international survey. RESULTS:Panels endorsed the four-stage SMS system and referral algorithm. Among all survey respondents (n = 120), high acceptability was reported. Among non-spine clinicians (n = 32), 94% found the tool easy to understand, 91% considered the format suitable for clinical use, and 91% anticipated improved referrals. Overall, 88% would use the tool at least occasionally, including 55% who would use it frequently or always. CONCLUSION/CONCLUSIONS:The SMS staging system and referral tool (link) was rated feasible by expert panels and survey respondents. However, only 32 of 120 survey respondents (27%) were non-spine clinicians, so findings in this group are preliminary and may overstate acceptance. The tool should be considered provisional: prospective studies are needed to validate effects on referral and patient outcomes.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Myxopapillary ependymomas (MPE) and intradural lumbosacral schwannomas may be challenging to distinguish based on presenting characteristics and preoperative imaging. Accurate differentiation is crucial, as MPEs carry a risk of cerebrospinal fluid dissemination and warrant earlier intervention, a more tailored surgical strategy, consideration for adjuvant radiation, and frequent surveillance. Here, we describe our institutional experience with these tumors and develop a radiomics-based machine learning model to help distinguish them on preoperative imaging. METHODS:Institutional surgical records from 2011 to 2025 were queried and clinical data were extracted for the retrospective cohort analysis. Tumors were manually segmented in ITK-Snap from T1 postcontrast images, and radiomics features were extracted using the PyRadiomics package. An ensemble of random forest, k-nearest neighbors, and naive Bayes classifiers was trained on a subset of radiomics features using nested cross-validation. RESULTS:< .001) in MPEs, likely due to longitudinal tumor growth along the filum. Excluding scoliotic patients did not significantly alter discrimination, suggesting robustness to vertebral column malalignment that may coexist with intradural tumors. CONCLUSION/CONCLUSIONS:A radiomics-based machine learning model demonstrated excellent discriminative ability between MPE and lumbosacral schwannoma, achieving high accuracy and robustness to vertebral alignment variations. These results suggest that radiomics-based models may be developed into a useful tool for preoperative planning and patient counseling.