Faculty Bibliography

BACKGROUND AND OBJECTIVE/OBJECTIVE:Neurofibromatosis-1 (NF1) dystrophic scoliosis is a challenging disease to manage surgically, with multiplanar curves progressing rapidly and unpredictably. Conservative management with bracing is often unsuccessful, and many patients necessitate instrumented fusion to halt progression of their curves. In rare cases, patients can present with spontaneous vertebral subluxation, significantly complicating the surgical management of this already complex disease process. The objective here was to describe 2 cases of vertebral subluxation in NF1-associated dystrophic scoliosis along with their surgical corrections and clinical courses. METHODS:A retrospective review of 2 cases at the authors' institution was performed to describe their preoperative symptom complexes, surgical corrections, and postoperative courses. A narrative review of the literature surrounding NF1-associated dystrophic scoliosis and subluxation is also presented. RESULTS:Two cases of vertebral subluxation at T4-5 and C7-T1 are presented. Both patients had significant dystrophic features throughout their spines, and halo-gravity traction was unsuccessful in 1 patient and led to vertebral and subclavian artery injuries in the other. One patient underwent an uncomplicated deformity correction with partial vertebral column resection to facilitate his deformity correction. The other patient, after her vascular injuries, ultimately suffered a spinal cord injury after a fall and underwent emergent instrumentation, decompression, and partial vertebral column resection at the site of subluxation, with improvement in her neurological function afterward. CONCLUSION/CONCLUSIONS:Dystrophic scoliosis in NF1 remains a difficult disease to treat, and deformity correction in patients with subluxation is particularly complex. These cases here highlight the unpredictability and possible complications of halo-gravity traction, need for good fixation to facilitate subluxation reduction, high chance of hardware complications and proximal or distal failure, and importance of cooperative management of these patients in conjunction with other surgical services.

OBJECTIVE:Cognitive impairment and pain catastrophizing are both associated with worse surgical outcomes. The aim of this study was to define the prevalence of cognitive impairment in patients with adult spinal deformity (ASD) and the relationships between cognitive impairment, pain catastrophizing, patient-reported outcome measures (PROMs), and frailty in the preoperative setting. METHODS:This cross-sectional study included patients undergoing evaluation for ASD correction at a single tertiary care center from January 2017 to October 2024. Patients were administered the Montreal Cognitive Assessment (MoCA), Pain Catastrophizing Scale (PCS), Scoliosis Research Society 22-item revised (SRS-22r) questionnaire, the Oswestry Disability Index (ODI), and the Edmonton Frail Scale (EFS). Median survey responses were compared between patients with any cognitive impairment (MoCA score < 26) and no cognitive impairment (MoCA score ≥ 26) using the Mann-Whitney U-test. Associations between survey responses were tested using Spearman's rank correlation analysis. Multivariate logistic regression analysis was performed to identify predictors of severe pain catastrophizing (PCS score ≥ 30). RESULTS:A total of 210 patients (61.4% female, median age 66.5 years) were included in the study. Of these, 123 (58.6%) had normal cognition and 87 (41.4%) had mild or moderate cognitive impairment. Patients with cognitive impairment had greater median PCS scores compared with patients with normal cognition (total PCS score 25.0 vs 19.0, p = 0.01). Lower MoCA scores were significantly correlated with higher PCS (ρ = -0.23, p = 0.0007) and EFS (ρ = -0.21, p = 0.0074) scores, but not ODI and total SRS-22r scores. In the multivariate logistic regression analysis, lower MoCA and SRS-22r scores were associated with greater odds of having severe pain catastrophizing (MoCA: OR 0.82 [95% CI 0.68-0.98], p = 0.03; SRS-22r: OR 0.05 [95% CI 0.01-0.19], p < 0.0001), while ODI score, EFS score, age, and sex were not associated. CONCLUSIONS:There was a high prevalence (41.4%) of cognitive impairment in patients with ASD. In both the correlation and multivariate logistic regression analyses, cognitive impairment was associated with pain catastrophizing and thus might contribute to pain perception and frailty in a way that is not consistently captured by traditional PROMs.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Three-column osteotomy (3CO) offers substantial spinal deformity correction. Thoracic neurovascular bundle sacrifice is often required, and anterior spinal artery (ASA) perfusion can be compromised. Spinal angiography allows localization of variable ASA vascular contribution. This study's objective was to describe a series of patients who underwent preoperative spinal angiography and discuss the impact on surgical planning and execution of thoracic 3CO for deformity correction. METHODS:Patients who underwent preoperative spinal angiograms and thoracic 3CO for deformity correction were reviewed. Preoperative, angiographic, and postoperative information was recorded. A literature review on preoperative spinal angiography in deformity surgery was performed. RESULTS:Eight patients were identified: single-level pedicle subtraction osteotomies (1), single-level vertebral column resections (2), and multilevel vertebral column resections (5). The average age was 40.0 years, and 75.0% were female. Thoracic scoliosis ranged from 0 to 105° preoperatively and 0 to 45.1° postoperatively. Thoracic kyphosis ranged from 29° to 120° preoperatively and 20.6° to 54.9° postoperatively. Twelve ASA supply vessels were identified bilaterally in 6 patients. Four patients had nontraditional ASA supply at T4 (1), T6 (1), and L2 (2), and 4 had multiple ASA feeders. Based on angiographic results, osteotomy site was changed (1), and neurovascular bundles were spared (2), a 37.5% rate of surgical plan alteration. There were no permanent neuromonitoring changes or postoperative neurologic deficits. No articles reported on using spinal angiography specifically for deformity surgery. CONCLUSION/CONCLUSIONS:Spinal angiography is low risk and provides critical information regarding ASA supply to potentially mitigate ischemic risk during neurovascular bundle takedown during thoracic 3CO. Further case series are warranted to evaluate the benefits in larger populations, but its clinical applications appear practical.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Anterior vertebral body tether (VBT) is a fusionless approach to treat idiopathic scoliosis, and surgeons are beginning to implement the technique into current practice. This study aims to evaluate the learning curve for single and double VBT. METHODS:A retrospective review of 3 surgeons' first 40 single and 20 double VBT was performed. Skeletally immature patients with idiopathic scoliosis who underwent thoracic (single) or thoracolumbar (double) VBT were included. Thoracic VBT was done via video-assisted thoracoscopic surgery and lumbar VBT through a mini-open retroperitoneal approach. Primary outcomes of interest were operative time, radiation exposure, and radiographic correction. Pooled and individual-surgeon analyses were performed. RESULTS:A total of 180 patients were included: 120 single and 60 double. Mean age was 12.7 years, and 87.8% were female. Mean segments tethered was 7.8 in single and 11.0 in double. Mean preoperative thoracic scoliosis was 51.5: single 50.5° and double 53.3°. Mean lumbar scoliosis was 36.4°: single 30.0° and double 49.0°. Average operating time was 276.2 minutes; double VBT was significantly longer (217.3 vs 394.0 minutes, P < .001). Mean blood loss was 198.5 mL, and mean fluoroscopy dose was 73.0 mGy. For single VBT, there was a decrease in operative time (283.3-174.8 minutes, P < .001) and fluoroscopy dose (70.1-53.5 mGy, P = .047) over time. Every 10 cases resulted in a 31.4 minute decrease in operative time (P < .001). There were no intraoperative complications. Single VBT resulted in 54.9% thoracic curve correction. Double VBT achieved 53.0% thoracic and 56.7% lumbar correction. There were no differences in curve correction across the learning curve. CONCLUSION/CONCLUSIONS:VBT is viable fusionless surgical option for scoliosis. As expected, increased experience resulted in shorter operative time; the threshold for such improvement seems to be 10 cases. Importantly, adequate and consistent curve correction can be achieved at the start of the learning curve while mitigating complications.

OBJECTIVE:This study aimed to assess whether elderly patients (aged ≥ 70 years) face an elevated risk of complications following pedicle subtraction osteotomy (PSO) for adult spinal deformity (ASD) compared with younger patients (< 70 years) and to evaluate if clinical and radiological outcomes differ between these age groups. METHODS:A retrospective analysis of 513 patients undergoing PSO for ASD by a single surgical team between January 2006 and January 2023 was conducted. Patients were categorized by age (≥ 70 years and < 70 years). Data on clinical, demographic, comorbidity, and radiographic details were collected and compared between the groups. For health-related quality of life assessment, the authors recorded the Oswestry Disability Index (ODI), numeric rating scale (NRS), and Scoliosis Research Society-22 revised (SRS-22r) scores preoperatively and at 6 weeks and 1 year postoperatively. Perioperative complications included major (neurological deficit, death, acute myocardial infarction, stroke), minor (ileus, arrhythmia, delirium), and intraoperative (durotomy, vascular injury). RESULTS:Of 513 patients, 412 were included in the study. Clinical outcomes, as measured by NRS, ODI, and SRS-22r scores, were comparable between groups, with both groups showing significant improvements postoperatively. Radiographic outcomes also showed significant and comparable improvements in sagittal balance and spinopelvic harmony in both groups. Deformity corrections were also well maintained at 1 year postoperatively. The elderly group (mean age 75.48 years) had a higher rate of perioperative complications (44.64%) than the younger group (mean age 59.60 years; 30.33%) (p = 0.0030), primarily minor complications such as delirium and arrhythmia (16.07% vs 8.61%, p = 0.0279). There was no significant difference between groups regarding the major complication rate (elderly group: 20.83% vs younger group: 14.34%, p = 0.1087), intraoperative complication rate (2.98% vs 3.69%, p = 0.6949), short-term complication rate (10.12% vs 8.20%, p = 0.5024), mechanical complication rate (30.95% vs 32.79%, p = 0.6949), and reoperation rate due to mechanical complications (38.46% vs 43.75% p = 0.5470). CONCLUSIONS:Elderly patients undergoing PSO for ASD experience a higher rate of minor complications but can achieve clinical and radiological outcomes that are comparable to those of younger patients. The authors found no significant increase in major, intraoperative, short-term, or mechanical complication rates and their subsequent reoperation rates among the elderly. These findings underscore the effectiveness of PSO in improving the quality of life for patients with ASD across age groups, emphasizing the critical role of personalized perioperative management in enhancing outcomes and minimizing risks for all patients.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Intraoperative red blood cell (RBC) salvage is frequently used in contemporary spine surgery, despite clinical concern in its efficacy as a surrogate for blood-banked allogeneic packed RBCs (pRBCs). During spine surgery, salvaged RBCs (sRBCs) are exposed to injurious high-heat electrocautery, prolonged stasis, and abrasive pharmaceuticals, potentially making sRBCs a poor blood substitute. We therefore sought to scientifically and objectively define the quality of sRBCs in the context of complex spine surgery. METHODS:This is a single-center, prospective, nonrandomized controlled trial of patients undergoing posterior-based multilevel thoracolumbar instrumented fusion for spinal deformity with planned use of intraoperative RBC salvage between June 2022 and July 2023. Surgeries were performed by fellowship-trained spinal neurosurgeons and orthopedic surgeons. The participants were split based on transfusion of sRBCs (given sufficient yield) vs no sRBC transfusion. Primary outcomes were RBC electrolyte composition, indices, deformability, and integrity, which were evaluated in comparison blood samples: Baseline, pRBC, and sRBC. Secondary outcomes were related to clinical effects of sRBC transfusion. Morphological assessment used Stimulated Raman Histology and machine learning. Deformability was assessed using ektacytometry. RESULTS:A total of 174 patients were included. The mean age was 50.2years ±25.4, 58.6% was female, the mean level fused was 10.0 ± 3.9, and 58.0% received sRBCs (median 207.0 mL). sRBCs differed significantly on standard laboratory measures, had a high proportion (30.7%) of shrunken and irregularly spiculated morphologies, and demonstrated abnormal deformability and relaxation kinetics. The hemolysis index was significantly elevated in sRBCs (2.9 ± 1.8) compared with Baseline samples and pRBCs (P < .01). Transfusion of sRBCs was associated with suboptimal resuscitation and provided no practical clinical benefit. CONCLUSION/CONCLUSIONS:RBCs salvaged during posterior thoracolumbar spine surgery are irreversibly injured, with hemolysis index exceeding Food and Drug Administration and Council of Europe transfusion standards in all samples, questioning their efficacy and safety as a blood substitute.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Pediatric spine surgery has evolved considerably over the past century. No previous study conducted a bibliometric analysis of the corpus of pediatric spine surgery. We used big data and advanced bibliometric analyses to evaluate trends in the progression of pediatric spine surgery as a distinct field since the beginning of the 20th century. METHODS:A Web of Science query was designed to capture the representative corpus of pediatric spine literature. Statistical and bibliometric analyses were performed using various Python packages and the Bibliometrix R package. RESULTS:The collection, published from 1902 to 2023, comprised a total of 11 861 articles from 61 journals and 32 715 unique authors. The overall growth rate annually for publications was 5.08%. An upsurge in publications was seen in the 1980s, after the advent of specialty and subspecialty journals. Illustratively, over 90% of all articles pertaining to pediatric spine surgery were published in the past 3 decades. International and domestic collaboration also increased exponentially over this time period. Reference publication year spectroscopy allowed us to identify 75 articles that comprise the historical roots of modern pediatric spine surgery. There was a recent lexical evolution of topics and terms toward alignment, outcomes, and patient-centric terms. Coauthorship among under-represented groups increased since 1990, but remains low, with disparities persisting across journals. CONCLUSION/CONCLUSIONS:This comprehensive bibliometric analysis on the corpus of pediatric spine surgery offers insight into the evolving landscape of research, authorship, and publication trends over the past century. Advancements in the understanding of the natural history and technology have led the field to become increasingly outcomes focused, all of which have been fueled by pioneering authors. While diversity among authors improves, under-representation of various groups continues to persist, indicating a critical role for further outreach and promotion.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Clinical registries are critical for modern surgery and underpin outcomes research, device monitoring, and trial development. However, existing approaches to registry construction are labor-intensive, costly, and prone to manual error. Natural language processing techniques combined with electronic health record (EHR) data sets can theoretically automate the construction and maintenance of registries. Our aim was to automate the generation of a spine surgery registry at an academic medical center using regular expression (regex) classifiers developed by neurosurgeons to combine domain expertise with interpretable algorithms. METHODS:We used a Hadoop data lake consisting of all the information generated by an academic medical center. Using this database and structured query language queries, we retrieved every operative note written in the department of neurosurgery since our transition to EHR. Notes were parsed using regex classifiers and compared with a random subset of 100 manually reviewed notes. RESULTS:A total of 31 502 operative cases were downloaded and processed using regex classifiers. The codebase required 5 days of development, 3 weeks of validation, and less than 1 hour for the software to generate the autoregistry. Regex classifiers had an average accuracy of 98.86% at identifying both spinal procedures and the relevant vertebral levels, and it correctly identified the entire list of defined surgical procedures in 89% of patients. We were able to identify patients who required additional operations within 30 days to monitor outcomes and quality metrics. CONCLUSION/CONCLUSIONS:This study demonstrates the feasibility of automatically generating a spine registry using the EHR and an interpretable, customizable natural language processing algorithm which may reduce pitfalls associated with manual registry development and facilitate rapid clinical research.