Multidisciplinary surgical considerations for en bloc resection of sacral chordoma: review of recent advances and a contemporary single-center series.

OBJECTIVE: Contemporary management of sacral chordomas requires maximizing the potential for recurrence-free and overall survival while minimizing treatment morbidity. En bloc resection can be performed at various levels of the sacrum, with tumor location and volume ultimately dictating the necessary extent of resection and subsequent tissue reconstruction. Because tumor resection involving the upper sacrum may be quite destabilizing, other pertinent considerations relate to instrumentation and subsequent tissue reconstruction. The primary aim of this study was to survey the surgical approaches used for managing primary sacral chordoma according to location of lumbosacral spine involvement, including a narrative review of the literature and examination of the authors' institutional case series. METHODS: The authors performed a narrative review of pertinent literature regarding reconstruction and complication avoidance techniques following en bloc resection of primary sacral tumors, supplemented by a contemporary series of 11 cases from their cohort. Relevant surgical anatomy, advances in instrumentation and reconstruction techniques, intraoperative imaging and navigation, soft-tissue reconstruction, and wound complication avoidance are also discussed. RESULTS: The review of the literature identified several surgical approaches used for management of primary sacral chordoma localized to low sacral levels (mid-S2 and below), high sacral levels (involving upper S2 and above), and high sacral levels with lumbar involvement. In the contemporary case series, the majority of cases (8/11) presented as low sacral tumors that did not require instrumentation. A minority required more extensive instrumentation and reconstruction, with 2 tumors involving upper S2 and/or S1 levels and 1 tumor extending into the lower lumbar spine. En bloc resection was successfully achieved in 10 of 11 cases, with a colostomy required in 2 cases due to rectal involvement. All 11 cases underwent musculocutaneous flap wound closure by plastic surgery, with none experiencing wound complications requiring revision. CONCLUSIONS: The modern management of sacral chordoma involves a multidisciplinary team of surgeons and intraoperative technologies to minimize surgical morbidity while optimizing oncological outcomes through en bloc resection. Most cases present with lower sacral tumors not requiring instrumentation, but stabilizing instrumentation and lumbosacral reconstruction are often required in upper sacral and lumbosacral cases. Among efforts to minimize wound-related complications, musculocutaneous flap closure stands out as an evidence-based measure that may mitigate risk.

Pediatric all-terrain vehicle (ATV) related head injury rates and patterns: A 10-year nationwide analysis.

INTRODUCTION: The use of all-terrain vehicles (ATVs) carries significant risk of permanent injury and death, disproportionately affecting children. These injuries commonly affect the head and are especially severe among children as they are often unhelmeted and more likely than adults to experience rollover injuries. Many studies examining patients with ATV-related injuries are single-center cohort studies, with few focusing specifically on head injuries. In the present study, we aimed to characterize the annual incidence of ATV-related head injuries between 2012 and 2021, classify and compare head injury types, and identify descriptive characteristics of ATV-related head injury victims. METHODS: Using the US Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS) database, we queried all head injuries associated with operating or riding an ATV in children under 18 years-old from over 100 emergency departments (EDs). Patient information regarding age, race, sex, location of incident, diagnoses, and sequelae were analyzed. We also collected the estimated number of ATV-related head injuries from all US EDs using the NEISS algorithm provided by the database. RESULTS: Using the NEISS algorithm we identified 67,957 (95% CI: 43,608 - 92,305) total pediatric ATV-related head injuries between 2012 and 2021. The annual incidence of ATV-related head injury was similar throughout this study period except for a 20% increase during the COVID-19 pandemic period of 2019-2021 (2019: 6382 injuries, 2020: 6757 injuries, 2021: 7600 injuries). A subset of 1890 cases from approximately 100 EDs were then analyzed. Unspecified closed head injuries were the prevailing type of injury (38%, 900/1890), followed by concussions (27%, 510/1890). More severe injuries included intracranial hemorrhages in 91 children (3.8%, 91/1890). Injuries of all types were predominantly seen in 14-17 year-old's (780/1890, 41%) and in males (64.1%, 1211/1890). In addition, ATV-associated injuries were significantly more common in those coded as white (58.0%, 1096/1890) than any other racial group. ATV-associated accidents among children younger than 9 more commonly occurred at the home compared to accidents involving children older than 9 (57% vs. 32%, p < 0.0001). CONCLUSION: ATV-related head injuries cause a significant annual burden among children, with growing incidence in recent years. Further research may wish to explore potential benefits of helmet use and supervision of younger children in possible prevention of these accidents and their associated economic and non-economic costs.

The epidemiology of crib-related head injuries: A ten-year nationwide analysis.

INTRODUCTION: Falls from cribs resulting in head injury are understudied and poorly characterized. The purpose of this study was to advance current understanding of the prevalence, descriptive characteristics of injury victims, and the types of crib fall-related head injuries (CFHI) using queried patient cases from the National Electronic Injury Surveillance System (NEISS) database. METHODS: Using the US Consumer Product Safety Commission's System NEISS database, we queried all CFHIs among children from over 100 emergency departments (EDs). Patient information regarding age, race, sex, location of the incident, diagnoses, ED disposition, and sequelae were analyzed. The number of CFHI from all US EDs during each year was also collected from the database. RESULTS: There were an estimated 54,799 (95% CI: 30,228-79,369) total visits to EDs for CFHIs between 2012 and 2021, with a decrease in incidence of approximately 20% during the onset of the COVID-19 pandemic (2019: 5616 cases, 2020: 4459 cases). The annual incidence of injuries showed no significant trend over the 10-year study period. An available subset of 1782 cases of head injuries from approximately 100 EDs was analyzed, and 1442 cases were included in final analysis. Injuries were sorted into three primary categories: unspecified closed head injury (e.g., closed head injury, blunt head trauma, or traumatic brain injury), concussion, or open head injury and skull fracture. Unspecified closed head injuries were the most common of all head injuries (95.4%, 1376/1442). Open head injuries (14/1442, 0.97%) and concussions 3.6% (52/1442, 3.6%) were rare. Most injuries involved children under the age of 1 (42.6%) compared to children who were 1, 2, 3, or 4-years old. About a fourth of patients had other diagnoses in addition to their primary injury including scalp/forehead hematomas, emesis, and contusions. Female patients were more likely to present with other diagnoses in addition to their primary head injury (Difference: 12.3%, 95% CI: 9.87%-15.4%, p < .0001). CONCLUSION: Despite minimum rail height requirements set by the Consumer Safety Product Commission (CPSC), head injuries associated with crib falls are prevalent in the United States. However, most injuries were minor with a vast majority of patients being released following examination and treatment.

Spatiotemporal Distribution of Electrically Evoked Spinal Compound Action Potentials During Spinal Cord Stimulation.

OBJECTIVES: Recent studies using epidural spinal cord stimulation (SCS) have demonstrated restoration of motor function in individuals previously diagnosed with chronic spinal cord injury (SCI). In parallel, the spinal evoked compound action potentials (ECAPs) induced by SCS have been used to gain insight into the mechanisms of SCS-based chronic pain therapy and to titrate closed-loop delivery of stimulation. However, the previous characterization of ECAPs recorded during SCS was performed with one-dimensional, cylindrical electrode leads. Herein, we describe the unique spatiotemporal distribution of ECAPs induced by SCS across the medial-lateral and rostral-caudal axes of the spinal cord, and their relationship to polysynaptic lower-extremity motor activation. MATERIALS AND METHODS: In each of four sheep, two 24-contact epidural SCS arrays were placed on the lumbosacral spinal cord, spanning the L3 to L6 vertebrae. Spinal ECAPs were recorded during SCS from nonstimulating contacts of the epidural arrays, which were synchronized to bilateral electromyography (EMG) recordings from six back and lower-extremity muscles. RESULTS: We observed a triphasic P1, N1, P2 peak morphology and propagation in the ECAPs during midline and lateral stimulation. Distinct regions of lateral stimulation resulted in simultaneously increased ECAP and EMG responses compared with stimulation at adjacent lateral contacts. Although EMG responses decreased during repetitive stimulation bursts, spinal ECAP amplitude did not significantly change. Both spinal ECAP responses and EMG responses demonstrated preferential ipsilateral recruitment during lateral stimulation compared with midline stimulation. Furthermore, EMG responses were correlated with stimulation that resulted in increased ECAP amplitude on the ipsilateral side of the electrode array. CONCLUSIONS: These results suggest that ECAPs can be used to investigate the effects of SCS on spinal sensorimotor networks and to inform stimulation strategies that optimize the clinical benefit of SCS in the context of managing chronic pain and the restoration of sensorimotor function after SCI.

Evolution of surgical treatment of metastatic spine tumors.

PURPOSE: The treatment of cancer has transformed over the past 40 years, with medical oncologists, radiation oncologists and surgeons working together to prolong survival times and minimize treatment related morbidity. With each advancement, the risk-benefit scale has been calibrated to provide an accurate assessment of surgical hazard. The goal of this review is to look back at how the role of surgery has evolved with each new medical advance, and to explore the role of surgeons in the future of cancer care. METHODS: A literature review was conducted, highlighting the key papers guiding surgical management of spinal metastatic lesions. CONCLUSION: The roles of surgery, medical therapy, and radiation have evolved over the past 40 years, with new advances requiring complex multidisciplinary care.

Existing clinical evidence on the use of cellular bone matrix grafts in spinal fusion: updated systematic review of the literature.

OBJECTIVE: Spinal fusion surgery is increasingly common; however, pseudarthrosis remains a common complication affecting as much as 15% of some patient populations. Currently, no clear consensus on the best bone graft materials to use exists. Recent advances have led to the development of cell-infused cellular bone matrices (CBMs), which contain living components such as mesenchymal stem cells (MSCs). Relatively few clinical outcome studies on the use of these grafts exist, although the number of such studies has increased in the last 5 years. In this study, the authors aimed to summarize and critically evaluate the existing clinical evidence on commercially available CBMs in spinal fusion and reported clinical outcomes. METHODS: The authors performed a systematic search of the MEDLINE and PubMed electronic databases for peer-reviewed, English-language original articles (1970-2020) in which the articles' authors studied the clinical outcomes of CBMs in spinal fusion. The US National Library of Medicine electronic clinical trials database (www.ClinicalTrials.gov) was also searched for relevant ongoing clinical trials. RESULTS: Twelve published studies of 6 different CBM products met inclusion criteria: 5 studies of Osteocel Plus/Osteocel (n = 354 unique patients), 3 of Trinity Evolution (n = 114), 2 of ViviGen (n = 171), 1 of map3 (n = 41), and 1 of VIA Graft (n = 75). All studies reported high radiographic fusion success rates (range 87%-100%) using these CBMs. However, this literature was overwhelmingly limited to single-center, noncomparative studies. Seven studies disclosed industry funding or conflicts of interest (COIs). There are 4 known trials of ViviGen (3 trials) and Bio4 (1 trial) that are ongoing. CONCLUSIONS: CBMs are a promising technology with the potential of improving outcome after spinal fusion. However, while the number of studies conducted in humans has tripled since 2014, there is still insufficient evidence in the literature to recommend for or against CBMs relative to cheaper alternative materials. Comparative, multicenter trials and outcome registries free from industry COIs are indicated.

Pediatric National Surgical Quality Improvement Program: Useful for Quality Improvement in Craniosynostosis Surgery?

The American College of Surgeons and the American Pediatric Surgical Association collaborate to provide pediatric hospitals with multispeciality surgical outcomes data through the Pediatric National Surgical Quality Improvement Program (NSQIP Peds). The authors used this national multicenter database to describe 30-day outcomes from craniosynostosis surgery and identify associations with perioperative events and blood transfusion.Data from NSQIP Peds were used to describe children undergoing craniosynostosis surgery. The authors examined statistical association of clinical risk factors with the defined end point outcomes of perioperative complications and blood transfusion.Five hundred seventy-two surgeries were included. By Common Procedural Terminology codes, 93 identified as single suture synostosis, the remainder as multiple or unknown suture involvement. Location of the affected suture is not captured. Mean surgical time was 196.84 minutes (SD 113.46). Mean length of stay was 4.22 days (SD 5.04). Sixty-seven percent of patients received blood transfusions. 3.15% were other perioperative occurrences, including infection, wound disruption, unplanned reintubation, stroke/hemorrhage, cardiac arrest, seizures, thromboembolism. 2.8% were readmitted; 2.45% underwent reoperation within 30 days. Duration of surgery and length of hospital stay significantly differed in the presence of blood transfusion versus none. On multivariate analysis, duration from anesthesia start to surgery start, duration from surgery end to anesthesia end, and duration of operation were risk factors for blood transfusion.Pediatric NSQIP gives a national overview of 30-day outcome metrics in craniosynostosis surgery. Perioperative adverse event rate was 3.15%. Duration of surgery and duration of anesthesia were significantly associated with blood transfusion. The authors identified opportunities for pediatric NSQIP database improvement.

Infected Subgaleal Hematoma Following Blunt Head Trauma in a Child: Case Report and Review of the Literature.

Subgaleal hematoma (SGH), an uncommon but potentially dangerous complication, has been reported to occur with delivery in newborns, as well as in young patients following head trauma. Infection of a SGH is extremely rare, especially in cases where no disruption of the skin barrier occurs. We report a case of an infected SGH in an 8-month-old following closed skull fracture. The patient presented with scalp swelling 1 day after falling 3 feet. Initial evaluation found a nondisplaced skull fracture on computed tomography. She was discharged following an uneventful 23-hour observation. Three days later, she developed symptoms concerning for a viral upper respiratory tract infection and received symptomatic treatment. Nine days after injury, she returned with continued fevers, irritability, and significant increase in scalp swelling. Magnetic resonance imaging showed a subgaleal abscess with osteomyelitis. Needle aspiration revealed an infected hematoma with cultures positive for Streptococcus pneumoniae, treated with intravenous ampicillin. Purulent drainage from an enlarging necrotic needle aspiration site required subsequent surgical debridement of the subgaleal abscess with drain placement. She recovered well following surgery and intravenous antibiotics. Physicians should be aware that SGH carries a risk of serious morbidity and mortality. SGH can serve as a nidus for infection, typically from skin barrier breakdown or, as in this case, hematogenous spread. Early recognition, appropriate antibiotic therapy, and surgical debridement are critical in treating infected SGH.

Utility of Diffusion Tensor Imaging (DTI) for Prognosis and Management of Cervical Spondylotic Myelopathy: a PRISMA Review.

OBJECTIVE: As advances are made in quantitative magnetic resonance imaging, specifically diffusion tensor imaging, researchers have investigated its potential to serve as a biomarker of disease or prognosticator for post-operative recovery in the management of cervical spondylotic myelopathy. Here, we narratively review the current state of the emerging literature, describing areas of consensus and disagreement. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we queried two large databases for original manuscripts published in English and systematically produced a narrative review of the use of diffusion tensor imaging in the management of cervical spondylotic myelopathy. RESULTS: Of the 437 manuscripts initially returned in our query, 29 met the final inclusion criteria, and data were extracted regarding diffusion tensor imaging indices and their relationships with clinical outcomes following surgery. Preoperative fractional anisotropy was most commonly found to correlate closely with post-surgical clinical outcomes, though results were mixed. CONCLUSION: Preoperative fractional anisotropy most frequently and best correlates with functional outcomes following surgery for cervical spondylotic myelopathy, according to a review of the current literature. The findings were not universal and at times contradictory, highlighting the need for high-quality future investigations to better define the utility of diffusion tensor imaging in spinal disease.

Lumbar Decompression With and Without Fusion for Lumbar Stenosis With Spondylolisthesis: A Cost Utility Analysis.

STUDY DESIGN: Markov model. OBJECTIVE: To compare the cost-effectiveness of lumbar decompression alone (DA) with lumbar decompression with fusion (DF) for the management of adults undergoing surgery for lumbar stenosis with associated degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Rates of lumbar fusion have increased for all indications in the United States over the last 20 years. Recent randomized controlled trial data, however, have suggested comparable functional outcomes and lower reoperation rates for lumbar decompression and fusion as compared with DA in the treatment of lumbar stenosis with degenerative spondylolisthesis. MATERIALS AND METHODS: A multistate Markov model was constructed from the US payer perspective of a hypothetical cohort of patients with lumbar stenosis with associated spondylolisthesis requiring surgery. Data regarding clinical improvement, costs, and reoperation were generated from contemporary randomized trial evidence, meta-analyses of recent prospective studies, and large retrospective cohorts. Base case, one-way sensitivity analysis, and probabilistic sensitivity analyses were conducted, and the results were compared with a WTP threshold of $100,000 (in 2022 USD) over a two-year time horizon. A discount rate of 3% was utilized. RESULTS: The incremental cost and utility of DF relative to DA were $12,778 and 0.00529 aggregated quality adjusted life years. The corresponding incremental cost-effectiveness ratio of $2,416,281 far exceeded the willingness to pay threshold of $100,000. In sensitivity analysis, the results varied the most with respect to rate of improvement after DA, rate of improvement after lumbar decompression and fusion, and odds ratio of reoperation between the two groups. Zero percent of one-way and probabilistic sensitivity analyses achieved cost-effectiveness at the willingness-to-pay threshold. CONCLUSIONS: Within the context of contemporary surgical data, DF is not cost-effective compared with DA in the surgical management of lumbar stenosis with associated spondylolisthesis over a two-year time horizon.

Disparities in Primary Spinal Osseous Malignant Bone Tumor Survival by Medicaid Status: A National Population-Based Risk Analysis.

BACKGROUND: The impact of Medicaid status on survival outcomes of patients with spinal primary malignant bone tumors (sPMBT) has not been investigated. METHODS: Using the SEER-Medicaid database, adults diagnosed between 2006 and 2013 with sPMBT including chordoma, osteosarcoma, chondrosarcoma, Ewing sarcoma, or malignant giant cell tumor (GCT) were studied. Five-year survival analysis was performed using the Kaplan-Meier method. Adjusted survival analysis was performed using Cox proportional-hazards regression controlling for age, sex, marital status, cancer stage, poverty level, vertebral versus sacral location, geography, rurality, tumor diameter, tumor grade, tumor histology, and therapy. RESULTS: A total of 572 patients with sPMBT (Medicaid: 59, non-Medicaid: 513) were identified. Medicaid patients were more likely to be younger (P < 0.001), Black (P < 0.001), live in high poverty neighborhoods (P = 0.006), have distant metastases at diagnosis (P < 0.001), and less likely to receive surgery (P = 0.006). The 5-year survival rate was 65.7% (chondrosarcoma: 70.0%, chordoma: 91.5%, Ewing sarcoma: 44.6%, GCT: 90.0%, osteosarcoma: 34.2%). Medicaid patients had significantly worse 5-year survival than non-Medicaid patients (52.0% vs. 67.2%, P = 0.02). Minority individuals on Medicaid were associated with an increased risk of cancer-specific mortality compared with White non-Medicaid patients (adjusted hazard ratio [aHR] = 2.51, [95% CI 1.18-5.35], P = 0.017). Among Medicaid patients, those who received surgery had significantly better survival than those who did not (64.5% vs. 30.6%, P = 0.001). For all patients, not receiving surgery (aHR = 1.90 [1.23-2.95], P = 0.004) and tumor diameter >50 mm (aHR=1.89 [1.10-3.25], P = 0.023) were associated with an increased risk of mortality. CONCLUSIONS: Medicaid patients may be less likely to receive surgery and suffer from poorer survival. These disparities may be especially prominent among minorities.

Systematic Review of Prophylactic Plastic Surgery Closure to Prevent Postoperative Wound Complications Following Spine Surgery.

Spinal surgeries are increasingly performed in the United States, but complication rates can be unacceptably high at up to 26%. Consequently, plastic surgeons (PS) are sometimes recruited by spine surgeons (SS) for intraoperative assistance with soft tissue closures. An electronic multidatabase literature search was systematically conducted to determine whether spinal wound closure performed by PS minimizes postoperative wound healing complications when compared to closure by SS (neurosurgical or orthopedic), with the hypothesis that closures by PS minimizes incidence of complications. All published studies involving patients who underwent posterior spinal surgery with closure by PS or SS at index spine surgery were identified. Filtering by exclusion criteria identified 10 studies, 4 of which were comparative in nature and included both closures by PS and SS. Of these 4, none reported significant differences in postoperative outcomes between the groups. Across all studies, PS were involved in cases with higher baseline risk for wound complications and greater comorbidity burden. Closures by PS were significantly more likely to have had prior chemotherapy in 2 of the 4 (50%) studies (P = 0.014, P < 0.001) and radiation in 3 of the 4 (75%) studies (P < 0.001, P < 0.01, P < 0.001). In conclusion, closures by PS are frequently performed in higher risk cases, and use of PS in these closures may normalize the risk of wound complications to that of the normal risk cohort, though the overall level of evidence of the published literature is low.

Microbubble Contrast-Enhanced Transcutaneous Ultrasound Enables Real-Time Spinal Cord Perfusion Monitoring Following Posterior Cervical Decompression.

BACKGROUND: Ultrasound imaging is inexpensive, portable, and widely available. The development of a real-time transcutaneous spinal cord perfusion monitoring system would allow more precise targeting of mean arterial pressure goals following acute spinal cord injury (SCI). There has been no prior demonstration of successful real-time cord perfusion monitoring in humans. METHODS: Four adult patients who had undergone posterior cervical decompression and instrumentation at a single center were enrolled into this prospective feasibility study. All participants had undergone cervical laminectomies spanning ≥2 contiguous levels ≥2 months prior to inclusion with no history of SCI. The first 2 underwent transcutaneous ultrasound without contrast and the second 2 underwent contrast-enhanced ultrasound (CEUS) with intravenously injected microbubble contrast. RESULTS: Using noncontrast ultrasound with or without Doppler (n = 2), the dura, spinal cord, and vertebral bodies were apparent however ultrasonography was insufficient to discern intramedullary perfusion or clear white-gray matter differentiation. With application of microbubble contrast (n = 2), it was possible to quantify differential spinal cord perfusion within and between cross-sectional regions of the cord. Further, it was possible to quantify spinal cord hemodynamic perfusion using CEUS by measuring peak signal intensity and the time to peak signal intensity after microbubble contrast injection. Time-intensity curves were generated and area under the curves were calculated as a marker of tissue perfusion. CONCLUSIONS: CEUS is a viable platform for monitoring real-time cord perfusion in patients who have undergone prior cervical laminectomies. Further development has the potential to change clinical management acute SCI by tailoring treatments to measured tissue perfusion parameters.

An active electronic bidirectional interface for high resolution interrogation of the spinal cord.

Epidural electrical stimulation (EES) has shown promise as both a clinical therapeutic tool and research aid in the study of nervous system function. However, available clinical paddles are limited to using a small number of contacts due to the burden of wires necessary to connect each contact to the therapeutic device. Here, we introduce for the first time the integration of a hermetic active electronic multiplexer onto the electrode paddle array itself, removing this interconnect limitation. We evaluated the chronic implantation of an active electronic 60-contact paddle (the HD64) on the lumbosacral spinal cord of two sheep. The HD64 was implanted for 13 months and 15 months, with no device-related malfunctions or adverse events. We identified increased selectivity in EES-evoked motor responses using dense stimulating bipoles. Further, we found that dense recording bipoles decreased the spatial correlation between channels during recordings. Finally, spatial electrode encoding enabled a neural network to accurately perform EES parameter inference for unseen stimulation electrodes, reducing training data requirements. A high-density EES paddle, containing active electronics safely integrated into neural interfaces, opens new avenues for the study of nervous system function and new therapies to treat neural injury and dysfunction.

Effect of subthalamic nucleus or globus pallidus interna stimulation on oculomotor function in patients with Parkinson's disease.

BACKGROUND: Deep brain stimulation (DBS) of either the globus pallidus interna (GPi) or subthalamic nucleus (STN) is similarly effective for treating somatomotor manifestations of Parkinson's disease (PD), but differences in how stimulation of each target affects oculomotor function are poorly understood. OBJECTIVE: We sought to determine if stimulation of the STN, but not the GPi, affects oculomotor function in PD patients. METHODS: Nineteen PD patients with DBS implants (8 bilateral GPi, 9 bilateral STN and 2 unilateral STN) were studied. Testing was performed with stimulation on, then off. Somatomotor function was tested using the Unified Parkinson's Disease Rating Scale (UPDRS) motor exam. For oculomotor testing, patients performed pro- and antisaccade tasks while monitored with an infrared eye tracker. Saccadic latency, saccadic intrusions, and square-wave jerks (SWJs) were measured for each trial. RESULTS: As expected, UPDRS motor scores improved with both GPi and STN stimulation. With GPi stimulation, there was no significant difference in oculomotor function with stimulation on or off. However, with STN stimulation on, there was a significant increase in the mean number of SWJs/s, as well as a significant decrease in latency for both pro- and antisaccade tasks. CONCLUSION: Stimulation of either GPi or STN had similar effects on somatomotor function, but only STN stimulation significantly altered oculomotor function.

Early Outcomes of Muscle Flap Closures in Posterior Thoracolumbar Fusions: A Propensity-Matched Cohort Analysis.

BACKGROUND: Plastic surgery closure with muscle flaps after complex spinal reconstruction has become increasingly common. Existing evidence for this practice consists of small, uncontrolled, single-center cohort studies. We aimed to compare 30-day postoperative wound-related complication rates between flap closure and traditional closure after posterior thoracolumbar fusions (PTLFs) for non-infectious, non-oncologic pathologies using a national database. METHODS: We performed a propensity-matched analysis using the 2012-2020 National Surgical Quality Improvement Program dataset to compare 30-day outcomes between PTLFs with flap closure versus traditional closure. RESULTS: A total of 100,799 PTLFs met our inclusion criteria. The use of flap closure with PTLF remained low but more than doubled from 2012 to 2020 (0.38% vs. 0.97%; P = 0.002). A higher proportion of flap closures had higher American Society of Anesthesiologists classifications and higher number of operated spine levels (all P < 0.001). We included 1907 PTLFs (630 for flap closure; 1257 for traditional closure) in the propensity-matched cohort. Unadjusted 30-day wound complication rates were 1.7% for flap and 2.1% for traditional closure (P = 0.76). After adjusting for operative time, wound complication, readmission, reoperation, mortality, and non-wound complication were not associated flap use (all P > 0.05). CONCLUSIONS: Plastic surgery closure was performed in patients with a higher comorbidity burden, suggesting consultation in sicker patients. Although higher rates of wound and non-wound complications were expected for the flap cohort, our propensity-matched cohort analysis of flap closure in PTLFs resulted in non-inferior odds of wound complications compared to traditional closure. Further study is needed to assess long-term complications in prophylactic flap closure in complex spine surgeries.

Performance of ChatGPT and GPT-4 on Neurosurgery Written Board Examinations.

BACKGROUND AND OBJECTIVES: Interest surrounding generative large language models (LLMs) has rapidly grown. Although ChatGPT (GPT-3.5), a general LLM, has shown near-passing performance on medical student board examinations, the performance of ChatGPT or its successor GPT-4 on specialized examinations and the factors affecting accuracy remain unclear. This study aims to assess the performance of ChatGPT and GPT-4 on a 500-question mock neurosurgical written board examination. METHODS: The Self-Assessment Neurosurgery Examinations (SANS) American Board of Neurological Surgery Self-Assessment Examination 1 was used to evaluate ChatGPT and GPT-4. Questions were in single best answer, multiple-choice format. χ 2 , Fisher exact, and univariable logistic regression tests were used to assess performance differences in relation to question characteristics. RESULTS: ChatGPT (GPT-3.5) and GPT-4 achieved scores of 73.4% (95% CI: 69.3%-77.2%) and 83.4% (95% CI: 79.8%-86.5%), respectively, relative to the user average of 72.8% (95% CI: 68.6%-76.6%). Both LLMs exceeded last year's passing threshold of 69%. Although scores between ChatGPT and question bank users were equivalent ( P = .963), GPT-4 outperformed both (both P < .001). GPT-4 answered every question answered correctly by ChatGPT and 37.6% (50/133) of remaining incorrect questions correctly. Among 12 question categories, GPT-4 significantly outperformed users in each but performed comparably with ChatGPT in 3 (functional, other general, and spine) and outperformed both users and ChatGPT for tumor questions. Increased word count (odds ratio = 0.89 of answering a question correctly per +10 words) and higher-order problem-solving (odds ratio = 0.40, P = .009) were associated with lower accuracy for ChatGPT, but not for GPT-4 (both P > .005). Multimodal input was not available at the time of this study; hence, on questions with image content, ChatGPT and GPT-4 answered 49.5% and 56.8% of questions correctly based on contextual context clues alone. CONCLUSION: LLMs achieved passing scores on a mock 500-question neurosurgical written board examination, with GPT-4 significantly outperforming ChatGPT.

The burden of unhelmeted motorcycle injury: A nationwide scoring-based analysis of helmet safety legislation.

INTRODUCTION: Motorcycle collisions comprise a large portion of motor vehicle injuries and fatalities with over 80,000 injuries and 5,500 fatalities per year in the United States. Unhelmeted riders have poor medical outcomes and generate billions in costs. Despite helmet use having been shown to lower the risk of neurological injury and death, helmet compliance is not universal, and legislation concerning helmet use also varies widely across the United States. METHODS: In this study, we systematically reviewed helmet-related statutes from all US jurisdictions. We evaluated the stringency of these statutes using a legislative scoring system termed the Helmet Safety Score (HSS) ranging from 0-7 points, with higher scores denoting more stringent statutes. Regression modeling was used to predict unhelmeted mortality using our safety scores. RESULTS: The mean score across all jurisdictions was 4.73. We found jurisdictions with higher HSS's generally had lower percentages of unhelmeted fatalities in terms of total fatalities as well as per 100,000 people and 100,000 registered motorcycles. In contrast, some lower-scoring jurisdictions had over 100 times more unhelmeted fatalities than higher-scoring jurisdictions. Our HSS significantly predicted unhelmeted motorcycle fatalities per 100,000 people (ß = -0.228 per 1-point increase, 95% CI: -0.288 to -0.169, p < .0001) and per 100,000 registered motorcycles (ß = -6.17 per 1-point increase, 95% CI: -8.37 to -3.98, p < .0001) in each state. Aspects of our score concerning helmet exemptions for riders and motorcycle-type vehicles independently predicted higher fatalities (p < .0001). Higher safety scores predicted lower unhelmeted fatalities. CONCLUSION: Stringent helmet laws may be an effective mechanism for decreasing unhelmeted mortality. Therefore, universal helmet laws may be one such mechanism to decrease motorcycle-related neurological injury and fatality burden. In states with existing helmet laws, elimination of exemptions for certain riders and motorcycle-type vehicles may also decrease fatalities.

Long-Term Motor versus Sensory Lumbar Plexopathy After Lateral Lumbar Interbody Fusion: Single-Center Experience, Intraoperative Neuromonitoring Results, and Multivariate Analysis of Patient-Level Predictors.

BACKGROUND: Although lateral lumbar interbody fusion (LLIF) is an effective surgical option for lumbar arthrodesis, postoperative plexopathies are a common complication. We characterized post-LLIF plexopathies in a large cohort and analyzed potential risk factors for each. METHODS: A single-institutional cohort who underwent LLIF between May 2015 and December 2019 was retrospectively reviewed for postoperative lumbar plexopathies. Plexopathies were divided based on sensory and motor symptoms and duration, as well as by laterality relative to the surgical approach. We assessed these subgroups for associations with patient and surgical characteristics as well as psoas dimensions. We then evaluated risk of developing plexopathies after intraoperative neuromonitoring observations. RESULTS: A total of 127 patients were included. The overall rate of LLIF-induced sensory or motor lumbar plexopathy was 37.8% (48/127). Of all cases, 42 were ipsilateral to the surgical approach (33.1%); conversely, 6 patients developed contralateral plexopathies (4.7%). Most (31/48; 64.6%) resolved with a follow-up interval of 402 days in the plexopathy group. Of ipsilateral cases, 24 patients experienced persistent (>90 days) postoperative sensory symptoms (18.9%), whereas 20 experienced persistent weakness (15.7%). More levels fused predicted persistent sensory symptoms (odds ratio, 1.714 [1.246-2.359]; P = 0.0085), whereas surgical duration predicted persistent weakness (odds ratio, 1.004 [1.002-1.006]; P = 0.0382). Psoas anatomic variables were not significantly associated with plexopathy. Nonresolution of intraoperative evoked motor potential alerts was a significant risk factor for developing plexopathies (relative risk, 2.29 [1.17-4.45]). CONCLUSIONS: Post-LLIF plexopathies are common but usually resolve. Surgical complexity and unresolved neuromonitoring alerts are possible risk factors for persistent plexopathy.

Performance of ChatGPT, GPT-4, and Google Bard on a Neurosurgery Oral Boards Preparation Question Bank.

BACKGROUND AND OBJECTIVES: General large language models (LLMs), such as ChatGPT (GPT-3.5), have demonstrated the capability to pass multiple-choice medical board examinations. However, comparative accuracy of different LLMs and LLM performance on assessments of predominantly higher-order management questions is poorly understood. We aimed to assess the performance of 3 LLMs (GPT-3.5, GPT-4, and Google Bard) on a question bank designed specifically for neurosurgery oral boards examination preparation. METHODS: The 149-question Self-Assessment Neurosurgery Examination Indications Examination was used to query LLM accuracy. Questions were inputted in a single best answer, multiple-choice format. χ 2 , Fisher exact, and univariable logistic regression tests assessed differences in performance by question characteristics. RESULTS: On a question bank with predominantly higher-order questions (85.2%), ChatGPT (GPT-3.5) and GPT-4 answered 62.4% (95% CI: 54.1%-70.1%) and 82.6% (95% CI: 75.2%-88.1%) of questions correctly, respectively. By contrast, Bard scored 44.2% (66/149, 95% CI: 36.2%-52.6%). GPT-3.5 and GPT-4 demonstrated significantly higher scores than Bard (both P < .01), and GPT-4 outperformed GPT-3.5 ( P = .023). Among 6 subspecialties, GPT-4 had significantly higher accuracy in the Spine category relative to GPT-3.5 and in 4 categories relative to Bard (all P < .01). Incorporation of higher-order problem solving was associated with lower question accuracy for GPT-3.5 (odds ratio [OR] = 0.80, P = .042) and Bard (OR = 0.76, P = .014), but not GPT-4 (OR = 0.86, P = .085). GPT-4's performance on imaging-related questions surpassed GPT-3.5's (68.6% vs 47.1%, P = .044) and was comparable with Bard's (68.6% vs 66.7%, P = 1.000). However, GPT-4 demonstrated significantly lower rates of "hallucination" on imaging-related questions than both GPT-3.5 (2.3% vs 57.1%, P < .001) and Bard (2.3% vs 27.3%, P = .002). Lack of question text description for questions predicted significantly higher odds of hallucination for GPT-3.5 (OR = 1.45, P = .012) and Bard (OR = 2.09, P < .001). CONCLUSION: On a question bank of predominantly higher-order management case scenarios for neurosurgery oral boards preparation, GPT-4 achieved a score of 82.6%, outperforming ChatGPT and Google Bard.