Faculty Bibliography

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.

STUDY DESIGN/METHODS:Retrospective review of a prospectively collected multicenter database. OBJECTIVE:To compare outcomes of patients with cerebral palsy (CP) who undergo surgery for scoliosis with normal lordosis (NL) versus hyperlordosis. SUMMARY OF BACKGROUND DATA/BACKGROUND:Surgical correction of scoliosis with lumbar hyperlordosis is challenging. Hyperlordosis may confer higher perioperative morbidity, but this is not well understood. MATERIALS AND METHODS/METHODS:A multicenter database was queried for CP patients who underwent surgery from 2008 to 2017. The minimum follow-up was 2 years. Two groups were identified: lumbar lordosis <75° (NL) versus ≥ 75° hyperlordosis (HL). Perioperative, radiographic, and clinical outcomes were compared. RESULTS:Two hundred seventy-five patients were studied: 236 NL and 39 HL (-75 to -125°). The mean age was 14.1 years, and 52.4% were male. Patients with hyperlordosis had less cognitive impairment (76.9% vs. 94.0%, P =0.008) and higher CPCHILD scores (59.4 vs. 51.0, P =0.003). Other demographics were similar between the groups. Patients with hyperlordosis had greater lumbar lordosis (-90.5 vs. -31.5°, P <0.001) and smaller sagittal vertical axis (-4.0 vs. 2.6 cm, P <0.001). Patients with hyperlordosis had greater estimated blood loss (2222.0 vs. 1460.7 mL, P <0.001) but a similar perioperative complication rate (20.5% vs. 22.5%, P =0.787). Significant correction of all radiographic parameters was achieved in both groups. The HL group had postoperative lumbar lordosis of -68.2° and sagittal vertical axis of -1.0 cm. At a 2-year follow-up, patients with hyperlordosis continued to have higher CPCHILD scores and gained the greatest benefit in overall quality of life measures (20.0 vs. 6.1, P =0.008). The reoperation rate was 10.2%: implant failure (3.6%), pseudarthrosis (0.7%), and wound complications (7.3%). There were no differences in the reoperation rate between the groups. CONCLUSION/CONCLUSIONS:Surgical correction of scoliosis with hyperlordosis is associated with greater estimated blood loss but similar radiographic results, perioperative morbidity, and reoperation rate as normal lordosis. Patients with hyperlordosis gained greater overall health benefits. Correction of ≥25% of hyperlordosis seems satisfactory. LEVEL OF EVIDENCE/METHODS:3.

Over the past generation, outcome measures in spine care have evolved from a reliance on clinician-reported assessment toward recognizing the importance of the patient's perspective and the wide incorporation of patient-reported outcomes (PROs). While patient-reported outcomes are now considered an integral component of outcomes assessments, they cannot wholly capture the state of a patient's functionality. There is a clear need for quantitative and objective patient-centered outcome measures. The pervasiveness of smartphones and wearable devices in modern society, which passively collect data related to health, has ushered in a new era of spine care outcome measurement. The patterns emerging from these data, so-called "digital biomarkers," can accurately describe characteristics of a patient's health, disease, or recovery state. Broadly, the spine care community has thus far concentrated on digital biomarkers related to mobility, although the researcher's toolkit is anticipated to expand in concert with advancements in technology. In this review of the nascent literature, we describe the evolution of spine care outcome measurements, outline how digital biomarkers can supplement current clinician-driven and patient-driven measures, appraise the present and future of the field in the modern era, as well as discuss present limitations and areas for further study, with a focus on smartphones (see Supplemental Digital Content , http://links.lww.com/NEU/D809 , for a similar appraisal of wearable devices).

OBJECTIVE:By minimizing imaging artifact and particle scatter, carbon fiber-reinforced polyetheretherketone (CF-PEEK) spinal implants are hypothesized to enhance radiotherapy (RT) planning/dosing and improve oncological outcomes. However, robust clinical studies comparing tumor surgery outcomes between CF-PEEK and traditional metallic implants are lacking. In this paper, the authors performed a systematic review of the literature with the aim to describe clinical outcomes in patients with spine tumors who received CF-PEEK implants, focusing on implant-related complications and oncological outcomes. METHODS:A systematic review of the literature published between database inception and May 2022 was performed in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The PubMed database was queried using the terms "carbon fiber" and "spine" or "spinal." The inclusion criteria were articles that described patients with CF-PEEK pedicle screw fixation and had a minimum of 5 patients. Case reports and phantom studies were excluded. RESULTS:This review included 11 articles with 326 patients (237 with CF-PEEK-based implants and 89 with titanium-based implants). The mean follow-up period was 13.5 months, and most tumors were metastatic (67.1%). The rates of implant-related complications in the CF-PEEK and titanium groups were 7.8% and 4.7%, respectively. The rate of pedicle screw fracture was 1.7% in the CF-PEEK group and 2.4% in the titanium group. The rates of reoperation were 5.7% (with 60.0% because of implant failure or junctional kyphosis) and 4.8% (all because of implant failure or junctional kyphosis) in the CF-PEEK and titanium groups, respectively. When reported, 72.5% of patients received postoperative RT (41.0% stereotactic body RT, 30.8% fractionated RT, 25.6% proton, 2.6% carbon ion). Four articles suggested that implant artifact was reduced in the CF-PEEK group. Local recurrence occurred in 14.4% of CF-PEEK and 10.7% of titanium-implanted patients. CONCLUSIONS:While CF-PEEK harbors similar implant failure rates to traditional metallic implants with reduced imaging artifact, it remains unclear whether CF-PEEK implants improve oncological outcomes. This study highlights the need for prospective, direct comparative clinical studies.

STUDY DESIGN/METHODS:Retrospective comparative study. OBJECTIVE:To assess the relationship of fusion mass bone density on computed tomography (CT) and the development of rod fractures (RFs) and proximal junctional kyphosis (PJK). SUMMARY OF BACKGROUND DATA/BACKGROUND:Few studies have evaluated the relationship of fusion mass bone density to mechanical complications. MATERIALS AND METHODS/METHODS:A retrospective review of adult spinal deformity patients who underwent thoracolumbar three-column osteotomy from 2007 to 2017 was performed. All patients underwent routine 1-year CT imaging and had at least 24 months follow-up. Posterior fusion mass bone density was evaluated by measuring hounsfield unit (HU) on CT in three different regions [upper instrumented vertebra (UIV), lower instrumented vertebra, and osteotomy site], and were compared between patients with and without mechanical complications. RESULTS:A total of 165 patients (63.2 years, 33.5% male) were included. Overall PJK rate was 18.8%, and 35.5% of these underwent PJK revision. There was significantly lower density of posterior fusion mass at the UIV in patients who experienced PJK compared with patients without PJK (431.5HU vs. 537.4HU, P =0.026). Overall RF rate was 34.5% and 61.4% of these underwent revision for RFs. Among 57 patients with RFs, 71.9% had pseudarthrosis. Fusion mass density did not differ between patients with or without RFs. However, in RF patients with pseudarthrosis, there was significantly higher bone mass density near the osteotomy compared with those without pseudarthrosis (515.7HU vs. 354.2HU, P =0.012). There were no differences in radiographic sagittal measures between the patients with and without RF or PJK. CONCLUSIONS:Patients with PJK tend to have less dense posterior fusion mass at the UIV. Fusion mass density does not correlate with RF, but greater bone density near the osteotomy was correlated with accompanying pseudarthrosis in patients with RFs. Assessing density of posterior fusion mass on CT may be helpful in assessing risk for PJK and provide insight as to the causes of RFs.

BACKGROUND:Hirayama disease (HD) is a rare, nonfamilial neuromuscular disease causing cervical myelopathy and deformity, most commonly effecting pubertal Asian males. Patients whose nonoperative treatment fails and who cannot tolerate long-term cervical immobilization, experience relapse after arrest of symptoms, or present with severe features warrant surgical treatment. Here, the authors present an unusual case of HD that resulted in rapid progression of severe cervical kyphosis and discuss surgical management strategies. OBSERVATIONS/METHODS:A 15-year-old male presented with unprovoked neck pain, progressive chin-on-chest phenomenon, and cervical myelopathy. Imaging revealed a severe subaxial cervical kyphosis of 88° and severe spinal cord compression secondary to changes within the thecal sac, ligaments, and bony elements. He underwent a multistage surgery involving halo gravity traction, C3-6 anterior cervical discectomy and fusion, and C2 to T2 posterior instrumented fusion with C3-5 Smith-Petersen osteotomies. Cervical subaxial pedicle screws facilitated deformity correction through a cantilever technique. LESSONS/CONCLUSIONS:HD is rare and often self-limited. For severe or refractory cases of HD, guidelines for surgical management have been suggested, with a variety of approaches deemed efficacious. This is the first case of a patient presenting with such severe cervical deformity; early diagnosis and recognition is the first step toward prompt, adequate management.

BACKGROUND:Spine abnormalities are a common manifestation of Neurofibromatosis Type 1 (NF1); however, the outcomes of surgical treatment for NF1-associated spinal deformity are not well explored. The purpose of this study was to investigate the outcome and risk profiles of multilevel fusion surgery for NF1 patients. METHODS:The National Inpatient Sample was queried for NF1 and non-NF1 patient populations with neuromuscular scoliosis who underwent multilevel fusion surgery involving eight or more vertebral levels between 2004 and 2017. Multivariate regression modeling was used to explore the relationship between perioperative variables and pertinent outcomes. RESULTS:Of the 55,485 patients with scoliosis, 533 patients (0.96%) had NF1. Patients with NF1 were more likely to have comorbid solid tumors (P < 0.0001), clinical depression (P < 0.0001), peripheral vascular disease (P < 0.0001), and hypertension (P < 0.001). Following surgery, NF1 patients had a higher incidence of hydrocephalus (0.6% vs. 1.9% P = 0.002), seizures (4.9% vs. 5.7% P = 0.006), and accidental vessel laceration (0.3% vs.1.9% P = 0.011). Although there were no differences in overall complication rates or in-hospital mortality, multivariate regression revealed NF1 patients had an increased probability of pulmonary (OR 0.5, 95%CI 0.3-0.8, P = 0.004) complications. There were no significant differences in utilization, including nonhome discharge or extended hospitalization; however, patients with NF1 had higher total hospital charges (mean -$18739, SE 3384, P < 0.0001). CONCLUSIONS:These findings indicate that NF1 is associated with certain complications following multilevel fusion surgery but does not appear to be associated with differences in quality or cost outcomes. These results provide some guidance to surgeons and other healthcare professionals in their perioperative decision making by raising awareness about risk factors for NF1 patients undergoing multilevel fusion surgery. We intend for this study to set the national baseline for complications after multilevel fusion in the NF1 population.

OBJECTIVE:Spinal meningiomas pose unique challenges based on the location of their dural attachment. However, there is a paucity of literature investigating the role of dural attachment location on outcomes after posterior-based approach for spinal meningioma resection. The aim of this study was to investigate any differences in outcomes between dural attachment location subgroups in spinal meningioma patients who underwent posterior-based resection. METHODS:This was a single-institution review of patients who underwent resection of a spinal meningioma from 1997 to 2017. Surgical, oncological, and neurological outcomes were compared between patients with varying dural attachments. Multivariate analysis was utilized. RESULTS:A total of 141 patients were identified. The mean age was 62 years, and 110 women were included. The sites of dural attachments were as follows: 16 (11.3%) dorsal, 31 (22.0%) dorsolateral, 17 (12.1%) lateral, 40 (28.4%) ventral, and 37 (26.2%) ventrolateral. Most meningiomas were WHO grade I (92.2%) and in the thoracic spine (61.0%). All patients underwent a posterior approach for tumor resection. There were no differences between subgroups in terms of largest diameter of tumor resected (p = 0.201), gross-total resection (GTR) or subtotal resection (p = 0.362), Simpson grade of resection, perioperative complications (p = 0.116), long-term neurological deficit (p = 0.100), or postoperative radiation therapy (p = 0.971). Cervical spine location was associated with reduced incidence of GTR (OR 0.271, 95% CI 0.108-0.684, p = 0.006) on multivariate analysis. The overall incidence of recurrence/progression was 4.6%, with no difference (p = 0.800) between subgroups. Similarly, the average length of follow-up was 28.1 months, with no difference between subgroups (p = 0.413). CONCLUSIONS:Posterior-based approaches for resection of spinal meningiomas are safe and effective, regardless of dural attachment location, with similar surgical, oncological, and neurological outcomes. Comparison of long-term recurrence rates between dural attachment subgroups is required.

BACKGROUND:Dumbbell schwannomas of the thoracic spine are challenging to cure surgically. Surgeons are familiar with posterolateral approaches to the spine, however, these may provide inadequate exposure for large tumors extending to ventral extraspinal compartments. Ventrolateral transpleural approaches offer direct access to the ventral thoracic spine and intrathoracic cavity, though are associated with increased morbidity and pulmonary complications, and may necessitate a staged procedure in order to address concomitant dorsal pathology. Herein we describe our experience with single-stage, posterior approach to dumbbell schwannomas with large ventral extraspinal components, and review the literature regarding surgical approaches for these tumors. METHODS:Retrospective review of patients who underwent a single-stage, posterior spinal surgery for thoracic dumbbell schwannomas from 2008 to 2018. Inclusion criteria were age > 18 years and ventral thoracic tumor component. RESULTS:Three patients underwent a simultaneous retropleural thoracotomy and posterior spinal approach, through a single incision, for the resection of dumbbell (intradural and extradural) schwannomas. Mean age was 49.7 years and 2 patients were female. All patients were neurologically intact at baseline. Lesions were 4-8.2 cm in the largest dimension (mean 6.1 cm). GTR was achieved in all patients. One pleural rent occurred intraoperatively; there were no other intraoperative or perioperative complications. At a mean follow-up of 14.1 months all patients remained motor and sensory intact and there was no evidence of recurrence. CONCLUSIONS:The combined retropleural thoracotomy-posterior spinal approach provides safe and sufficient access for resection of large dumbbell schwannomas of the thoracic spine.