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STUDY DESIGN: Systematic review of the literature and consensus recommendations by an international expert focus group. OBJECTIVE: To review and classify evidence in the literature regarding: (1) the role of neoadjuvant chemotherapy and (2) impact of extent of surgical resection on clinical outcome, particularly survival and local control, in patients with spinal Ewing sarcoma (ES) and osteosarcoma (OS). SUMMARY OF BACKGROUND DATA: ES and OS of the spine are currently managed with multimodality treatment involving chemotherapy, radiation therapy, and surgical resection. It is currently unclear if extent of resection, for example, intralesional resection versus marginal or wide resection has an impact on survival or local control of disease. METHODS: A systematic literature search for the years 1960 to 2008 was performed looking at publications involving treatment of spinal ES and OS. From these 208 articles, 16 were selected for analysis and were reviewed in depth. Studies were presented to a group of spinal oncology experts. Literature was graded for quality, summarized and presented to an international expert group with consensus recommendations generated. RESULTS: For ES of the spine, 10 studies were analyzed. For OS of the spine, 6 studies were analyzed. For both ES and OS of the spine, moderate level evidence supported a strong recommendation that neoadjuvant chemotherapy offers significant improvements in local control and long-term survival and is essential in multimodality management. For spinal ES, very low level evidence supported a weak recommendation that en bloc surgical resection provides improved local control, but not improved overall survival. Radiation therapy for spinal ES may also be used for local control either alone or to supplement incomplete resection. For spinal OS, very low evidence supported a strong recommendation that en bloc resection provides improved local control and potentially improved overall survival. CONCLUSION: Patients with ES and OS are currently managed with multiple modalities involving surgery, radiation, and chemotherapy. For both histopathologies, advances in chemotherapy have led to the greatest improvements in survival over the last few decades. Neoadjuvant therapy portents the most favorable local control and long-term survival. En bloc surgical resection may improve overall survival and decrease risk of recurrence. [ABSTRACT FROM AUTHOR]

Study Design: Case report. Objective: To report a case and review the literature on development of scoliosis following intrathecally placed opioid pump for chronic low back pain. Summary Of Background Data: Intrathecal opioid administration is a technique currently indicated for the management of chronic pain syndromes. Despite evidence of scoliosis occurring after baclofen pump insertion, there has been no evidence that development of scoliosis occurs following implantation of an intrathecally placed opioid pump for treatment of lower back pain (LBP). Methods: A retrospective review of patients with adult onset scoliosis was performed at our institution. One patient was identified as showing significant scoliotic progression following implantation of an intrathecally placed opioid pump. Radiographs were analyzed to evaluate the magnitude and configuration of her kyphoscoliosis following pump insertion. Results: A 50-year-old woman with intractable LBP underwent placement of a spinal cord stimulator (SCS) followed shortly by removal of the SCS and placement of an intrathecal opioid pump. Five years later, she presented with severe kyphoscoliosis involving a left thoracolumbar curve of 84 degrees and sagittal balance of 158 mm. Because of intractable pain and progressive deformity, she underwent multilevel osteotomies, instrumented fusion, and replacement of her Dilaudid pump. Postoperative radiographs demonstrated a residual 23 degrees thoracolumbar curve with restoration of her sagittal alignment. No major morbidity/mortality occurred with treatment. Conclusion: Although there may not be a direct correlation between implantation of an intrathecal opioid pump with subsequent development of adult onset scoliosis, deformity must be considered a potential sequela in patients treated with such neuromodulation. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study., Objectives: Surgical infections are unfortunately a fairly common occurrence in spine surgery, with rates reported as high as 16 %. However, there is a relative paucity of studies that look to understand how surgical infections may impact outcome variables. The aim of this study was to assess the impact of surgical infection on other perioperative complications, extended hospital length of stay (LOS), discharge disposition, and unplanned readmission following spine surgery., Methods: A retrospective cohort study was performed using the 2016-2022 ACS NSQIP database. Adults receiving spine surgery for trauma, degenerative disease, and tumors were identified using CPT and ICD-9/10 codes. Patients were divided into two cohorts: surgical infection (superficial surgical site infection, deep surgical site infection, organ space surgical site infection, or wound dehiscence) and no surgical infection (those who did not experience any infection). Patient demographics, comorbidities, intraoperative variables, postoperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analysis was utilized to identify predictors of AEs, extended hospital length of stay, non-routine discharge, and unplanned readmission., Results: In our cohort of 410,930 patients, 7854 (2.2 %) were found to have experienced a surgical infection. Regarding preoperative variables, a greater proportion of the surgical infection cohort was a female (p < 0.001) and had a higher mean BMI (p < 0.001), greater frailty and ASA scores (p < 0.001), and higher rates of all presenting comorbidities included in the study. Rates of AEs (p < 0.001), unplanned readmission (p < 0.001), reoperation (p < 0.001), non-home discharge (p < 0.001), and 30-day mortality were all greater in the surgical infection group when compared to the group without surgical infection. On multivariate analysis, surgical infection was found to be an independent predictor of experiencing postoperative complications [aOR: 6.15, 95 % CI: (5.72, 6.60), p < 0.001], prolonged LOS [2.71, 95 % CI: (2.54, 2.89), p < 0.001], non-routine discharge [aOR: 1.74, 95 % CI: (1.61, 1.88), p < 0.001], and unplanned readmission [aOR: 22.57, 95 % CI: (21.06, 24.19), p < 0.001]., Conclusions: Our study found that surgical infection increases the risk of complications, extended LOS, non-routine discharge, and unplanned readmission. Such findings warrant further studies that aim to validate these results and identify risk factors for surgical infections., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Risk Analysis Index (RAI) has been increasingly used to assess surgical frailty in various procedures, but its effectiveness in predicting mortality or in-patient hospital outcomes for spine surgery in metastatic disease remains unclear. The aim of this study was to compare the predictive values of the revised RAI (RAI-rev), the modified frailty index-5 (mFI-5), and advanced age for extended length of stay, 30-day readmission, complications, and mortality among patients undergoing spine surgery for metastatic spinal tumors., Methods: A retrospective cohort study was performed using the 2012-2022 ACS NSQIP database to identify adult patients who underwent spinal surgery for metastatic spinal pathologies. Using receiver operating characteristic (ROC) and multivariable analyses, we compared the discriminative thresholds and independent associations of RAI-rev, mFI-5, and greater patient age with extended length of stay (LOS), 30-day complications, hospital readmission, and mortality., Results: A total of 1,796 patients were identified, of which 1,116 (62.1%) were male and 1,008 (70.7%) were non-Hispanic White. RAI-rev identified 1,291 (71.9%) frail and 208 (11.6%) very frail patients, while mFI-5 identified 272 (15.1%) frail and 49 (2.7%) very frail patients. In the ROC analysis for extended LOS, both RAI-rev and mFI-5 showed modest predictive capabilities with area under the curve (AUC) values of 0.5477 and 0.5329, respectively, and no significant difference in their predictive abilities (p = 0.446). When compared to age, RAI-rev demonstrated superior prediction (p = 0.015). With respect to predicting 30-day readmission, no significant difference was observed between RAI-rev and mFI-5 (AUC 0.5394 l respectively, p = 0.354). However, RAI-rev outperformed age (p = 0.001). When assessing the risk of 30-day complications, RAI-rev significantly outperformed mFI-5 (AUC: 0.6016 and 0.5542 respectively, p = 0.022) but not age. Notably, RAI-rev demonstrated superior ability for predicting 30-day mortality compared to mFI-5 and age (AUC: 0.6541, 0.5652, and 0.5515 respectively, p < 0.001). Multivariate analysis revealed RAI-rev as a significant predictor of extended LOS [aOR: 1.96, 95% CI: 1.13-3.38, p = 0.016] and 30-day mortality [aOR: 5.27, 95% CI: 1.73-16.06, p = 0.003] for very frail patients. Similarly, the RAI-rev significantly predicted 30-day complications for frail [aOR: 2.63, 95% CI: 1.21-5.72, p = 0.015] and very frail [aOR: 3.69, 95% CI: 1.60-8.51, p = 0.002] patients. However, the RAI did not significantly predict 30-day readmission [Very Frail aOR: 1.52, 95% CI: 0.75-3.07, p = 0.245; Frail aOR: 1.46, 95% CI: 0.79-2.68, p = 0.225]., Conclusion: Our study demonstrates the utility of RAI-rev in predicting morbidity and mortality in patients undergoing spine surgery for metastatic spinal pathologies. Particularly, the superiority that RAI-rev has in predicting 30-day mortality may have significant implications in multidisciplinary decision making., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: This study investigates the predictive values of the Risk Analysis Index (RAI), the modified 5-item Frailty Index (mFI-5), and advanced age for predicting 30-day extended length of stay (LOS), 30-day complications and readmissions in patients undergoing posterior spinal fusion (PSF) for adult spinal deformity (ASD)., Methods: A retrospective cohort study was performed using the 2012-2021 ACS NSQIP database. Adults undergoing posterior spinal fusion for ASD were identified using CPT and ICD codes. Using receiver operating characteristic (ROC) and multivariable analyses, we compared the discriminative thresholds and independent associations of RAI, mFI-5, and greater patient age for extended LOS, 30-day complications and readmissions., Results: In this cohort of 3,814 patients, RAI identified 90.7% as Robust, 6.0% as Normal, and 3.3% as Frail/Very Frail, while mFI-5 classified 47.1% as Robust, 37.5% as Normal, and 15.3% as Frail/Very Frail. Multivariate analysis revealed both RAI and mFI-5 as significant predictors of extended LOS for Normal (RAI: p<0.001; mFI-5: p=0.012) and Frail/Very Frail patients (RAI: p<0.001; mFI-5: p=0.002). Additionally, RAI was a significant predictor of 30-day complication risk for Normal patients (p=0.005). Furthermore, mFI-5 was a significant predictor of 30-day readmission among Frail/Very Frail patients (p=0.002)., Conclusion: This study highlights the utility of RAI and mFI-5 in predicting extended LOS patients undergoing PSF for ASD. RAI was found to be superior to mFI-5 for predicting 30-day readmissions, while mF-5 was greater for 30-day complications. These findings highlight the importance of incorporating frailty assessments into preoperative surgical planning., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Postoperative bowel and bladder dysfunction (BBD) poses a significant risk following surgery of the sacral spinal segments and sacral nerve roots, particularly in neuro-oncology cases. The need for more reliable neuromonitoring techniques to enhance the safety of spine surgery is evident., Methods: We conducted a case series comprising 60 procedures involving 56 patients, spanning from September 2022 to January 2024. We assessed the diagnostic accuracy of sacral reflexes (bulbocavernosus and external urethral sphincter reflexes) and compared them with transcranial motor evoked potentials (TCMEP) incorporating anal sphincter (AS) and external urethral sphincter (EUS) recordings, as well as spontaneous electromyography (s-EMG) with AS and EUS recordings., Results: Sacral reflexes demonstrated a specificity of 100% in predicting postoperative BBD, with a sensitivity of 73.33%. While sensitivity slightly decreased to 64.71% at the 1-month follow-up, it remained consistently high overall. TCMEP with AS/EUS recordings did not identify any instances of postoperative BBD, whereas s-EMG with AS/EUS recordings showed a sensitivity of 14.29% and a specificity of 97.14%., Conclusion: Sacral reflex monitoring emerges as a robust adjunct to routine neuromonitoring, offering surgeons valuable predictive insights to potentially mitigate the occurrence of postoperative BBD., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Medical students are increasingly seeking out research opportunities to build their skills and network with future colleagues. Medical student-led conferences are an excellent endeavor to achieve this goal., Methods: The American Association of Neurological Surgeons student chapter at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell designed an in-person medical student research symposium alongside the Northwell Health Department of Neurosurgery. Postconference feedback forms were sent out digitally to student attendees to evaluate event planning and execution and responses were given on a scale of 1-5 (5 being the highest score)., Results: In December 2023, the Northeast Medical Student Research Symposium was held with over 80 participants and 52 medical student presenters. Keynote speakers delivered lectures geared toward students interested in neurosurgery and neuroscience research, followed by an interactive poster board session and resident/attending networking dinner. After the conference, students affirmed that they learned more about neuroscience research after the event (mean: 4.3), were more inclined to attend other neuroscience research events in the future (mean: 4.7), and would attend this event if held next year (mean: 4.8). The poster sessions (mean: 4.75) and keynote lectures (mean: 5) were the highest rated events, while the resident/attending networking dinner (mean: 3.6) was a potential area for improvement., Conclusions: Regional in-person conferences are an excellent way to foster interest in neurosurgery and neuroscience research, network with like-minded peers, and prepare students for presentations at national meetings., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Intraoperative bulbocavernosus reflex neuromonitoring has been utilized to protect bowel, bladder, and sexual function, providing a continuous functional assessment of the somatic sacral nervous system during surgeries where it is at risk. Bulbocavernosus reflex data may also provide additional functional insight, including an evaluation for spinal shock, distinguishing upper versus lower motor neuron injury (conus vs. cauda syndromes) and prognosis for postoperative bowel and bladder function. Continuous intraoperative bulbocavernosus reflex monitoring has been utilized to provide the surgeon with an ongoing functional assessment of the anatomical elements involved in the S2-S4 mediated reflex arc including the conus, cauda equina and pudendal nerves. Intraoperative bulbocavernosus reflex monitoring typically includes the electrical activation of the dorsal nerves of the genitals to initiate the afferent component of the reflex, followed by recording the resulting muscle response using needle electromyography recordings from the external anal sphincter., Methods: Herein we describe a complementary and novel technique that includes recording electromyography responses from the external urethral sphincter to monitor the external urethral sphincter reflex. Specialized foley catheters embedded with recording electrodes have recently become commercially available that provide the ability to perform intraoperative external urethral sphincter muscle recordings., Results: We describe technical details and the potential utility of incorporating external urethral sphincter reflex recordings into existing sacral neuromonitoring paradigms to provide redundant yet complementary data streams., Conclusions: We present two illustrative neurosurgical oncology cases to demonstrate the utility of the external urethral sphincter reflex technique in the setting of the necessary surgical sacrifice of sacral nerve roots., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 by the American Clinical Neurophysiology Society.)

Objective: Intramedullary spinal cord lipomas without spinal dysraphism are rare. Although they are benign tumors, they can cause significant neurological deficits. Their tight adherence to the spinal cord presents a challenge for resection. Therefore, we review our institutional experience treating adult patients with intramedullary lipomas in the absence of dysraphism and report long-term outcomes after resection., Methods: All adult patients undergoing resection of intramedullary spinal cord lipomas at a comprehensive cancer center between June 2011 and June 2023 were retrospectively identified. Patients with spinal dysraphism or extramedullary lipomas were excluded. Patients were included if they had microscopic surgical debulking with tissue sampling confirming the diagnosis., Results: Six patients were identified with a mean age of 35.0 ± 11.5 years, and 67% were female. Four cases localized to the thoracic spine. Symptoms included pain, numbness, and lower extremity motor weakness; only one patient reported bowel and bladder dysfunction. All patients experienced transient neurological decline in the immediate postoperative period. Five recovered to independent ambulation at long-term follow-up, including one recovering to full strength. One patient required a repeat resection after four years due to tumor progression and functional decline. Tumor progression was not recorded in the other patients., Conclusions: Subtotal resection is a safe and effective treatment. Detethering of the spinal cord, resection of exophytic components, and tumor debulking can improve symptoms and prevent further deterioration in most cases. The resection can be assisted using a laser to vaporize the fatty tissue of the lipoma without physical manipulation of the spinal cord., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Artificial intelligence (AI) has become increasingly used in neurosurgery. Generative pretrained transformers (GPTs) have been of particular interest. However, ethical concerns regarding the incorporation of AI into the field remain underexplored. We delineate key ethical considerations using a novel GPT-based, human-modified approach, synthesize the most common considerations, and present an ethical framework for the involvement of AI in neurosurgery., Methods: GPT-4, ChatGPT, Bing Chat/Copilot, You, Perplexity.ai, and Google Bard were queried with the prompt "How can artificial intelligence be ethically incorporated into neurosurgery?". Then, a layered GPT-based thematic analysis was performed. The authors synthesized the results into considerations for the ethical incorporation of AI into neurosurgery. Separate Pareto analyses with 20% threshold and 10% threshold were conducted to determine salient themes. The authors refined these salient themes., Results: Twelve key ethical considerations focusing on stakeholders, clinical implementation, and governance were identified. Refinement of the Pareto analysis of the top 20% most salient themes in the aggregated GPT outputs yielded 10 key considerations. Additionally, from the top 10% most salient themes, 5 considerations were retrieved. An ethical framework for the use of AI in neurosurgery was developed., Conclusions: It is critical to address the ethical considerations associated with the use of AI in neurosurgery. The framework described in this manuscript may facilitate the integration of AI into neurosurgery, benefitting both patients and neurosurgeons alike. We urge neurosurgeons to use AI only for validated purposes and caution against automatic adoption of its outputs without neurosurgeon interpretation., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Direct-wave (D-wave) neuromonitoring is a direct measure of corticospinal tract integrity that detects potential injury during spinal cord surgery. Epidural placement of electrodes used for D-wave measurements can result in high electrical impedances resulting in substantial signal noise that can compromise signal interpretation. Subdural electrode placement may offer a solution., Methods: Medical records for consecutive patients with epidural and subdural D-wave monitoring were reviewed. Demographic and clinical information including preoperative and postoperative motor strength were recorded. Neuromonitoring charts were reviewed to characterize impedances and signal amplitudes of D-waves recorded epidurally (before durotomy) and subdurally (following durotomy). Nonparametric statistics were used to compare epidural and subdural D-waves., Results: Ten patients (50% women, median age 50.5 years) were analyzed, of which five patients (50%) were functionally independent (modified McCormick grade ≤ II) preoperatively. D-waves were successfully acquired by subdural electrodes in eight cases and by epidural electrodes in three cases. Subdural electrode placement was associated with lower impedance values ( P = 0.011) and a higher baseline D-wave amplitude ( P = 0.007) relative to epidural placement. No association was observed between D-wave obtainability and functional status, and no adverse events relating to subdural electrode placement were encountered., Conclusions: Subdural electrode placement allows successful D-wave acquisition with accurate monitoring, clearer waveforms, and a more optimal signal-to-noise ratio relative to epidural placement. For spinal surgeries where access to the subdural compartment is technically safe and feasible, surgeons should consider subdural placement when monitoring D-waves to optimize clinical interpretation., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 by the American Clinical Neurophysiology Society.)

Background and Objectives: The palliative impact of spine surgery for metastatic disease is evolving with improvements in surgical technique and multidisciplinary cancer care. The goal of this study was to prospectively evaluate long-term clinical outcomes including health-related quality-of-life (HRQOL) measures, using spine cancer-specific patient-reported-outcome (PRO) measures, in patients with symptomatic spinal metastases who underwent surgical management., Methods: The Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO, ClinicalTrials.gov identifier: NCT01825161) trial is a prospective-observational cohort study that included 10 specialist centers in North America and Europe. Patients aged 18 to 75 years who underwent surgery for spinal metastases were included. Prospective assessments included both spine tumor-specific and generic PRO tools which were collected for a minimum of 2 years post-treatment or until death., Results: Two hundred and eighty patients (51.8% female, mean age 57.9 years) were included. At presentation, the mean Charlson Comorbidity Index was 6.0, 35.7% had neurological deficits as defined by the American Spinal Cord Injury Association scores, 47.2% had high-grade epidural spinal cord compression (2-3), and 89.6% had impending or frank instability as measured by a Spinal Instability Neoplastic Score of ≥7. The most common primary tumor sites were breast (20.2%), lung (18.8%), kidney (16.2%), and prostate (6.5%). The median overall survival postsurgery was 501 days, and the 2-year progression-free-survival rate was 38.4%. Compared with baseline, significant and durable improvements in HRQOL were observed at the 6-week, 12-week, 26-week, 1-year, and 2-year follow-up assessments from a battery of PRO questionnaires including the spine cancer-specific, validated, Spine Oncology Study Group Outcomes Questionnaire v2.0, the Short Form 36 version 2, EuroQol-5 Dimension (3L), and pain numerical rating scale score., Conclusion: Multi-institutional, prospective-outcomes data confirm that surgical decompression and/or stabilization provides meaningful and durable improvements in multiple HRQOL domains, including spine-specific outcomes based on the Spine Oncology Study Group Outcomes Questionnaire v2.0, for patients with metastatic spine disease., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Congress of Neurological Surgeons.)

This study aims to summarize sacrococcygeal chordoma literature through bibliometric analysis and to offer insights into key studies to guide clinical practices and future research. The Web of Science database was searched using the terms "sacral chordoma", "chordomas of the sacrum", "chordomas of the sacral spine", "chordomas of the sacrococcygeal region", "coccygeal chordoma", and "coccyx chordoma". Articles were analyzed for citation count, authorship, publication date, journal, research area tags, impact factor, and evidence level. The median number of citations was 75 (range: 53-306). The primary publication venue was the International Journal of Radiation Oncology, Biology, Physics. Most works, published between 1999 and 2019, featured a median journal impact factor of 3.8 (range: 2.1-7) and predominantly fell under the research area tag, radiation, nuclear medicine, and imaging. Of these articles, 19 provided clinical data with predominantly level III evidence, and one was a literature review. This review highlights the increasing volume of sacrococcygeal chordoma publications over the past two decades, indicating evolving treatment methods and interdisciplinary patient care. Advances in radiation, particularly intensity-modulated radiation therapy (IMRT) and proton beam therapy, are believed to be propelling research growth, and the lack of level I evidence underscores the need for more rigorous studies to refine treatment protocols for sacrococcygeal chordomas., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2024, Maity et al.)

Objective: Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear., Methods: PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158)., Results: The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion., Conclusions: Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.

Study Design: Retrospective cohort study., Objective: The aim of this study was to determine the relative importance and predicative power of the Hospital Frailty Risk Score (HFRS) on unplanned 30-day readmission after surgical intervention for metastatic spinal column tumors., Methods: All adult patients undergoing surgery for metastatic spinal column tumor were identified in the Nationwide Readmission Database from the years 2016 to 2018. Patients were categorized into 3 cohorts based on the criteria of the HFRS: Low(<5), Intermediate(5-14.9), and High(≥ 15). Random Forest (RF) classification was used to construct predictive models for 30-day patient readmission. Model performance was examined using the area under the receiver operating curve (AUC), and the Mean Decrease Gini (MDG) metric was used to quantify and rank features by relative importance., Results: There were 4346 patients included. The proportion of patients who required any readmission were higher among the Intermediate and High frailty cohorts when compared to the Low frailty cohort ( Low:33.9% vs. Intermediate:39.3% vs. High:39.2%, P < .001 ). An RF classifier was trained to predict 30-day readmission on all features (AUC = .60) and architecturally equivalent model trained using only ten features with highest MDG (AUC = .59). Both models found frailty to have the highest importance in predicting risk of readmission. On multivariate regression analysis, Intermediate frailty [ OR:1.32, CI(1.06,1.64), P = .012 ] was found to be an independent predictor of unplanned 30-day readmission., Conclusion: Our study utilizes machine learning approaches and predictive modeling to identify frailty as a significant risk-factor that contributes to unplanned 30-day readmission after spine surgery for metastatic spinal column metastases., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: Survey., Objective: In March of 2020, an original study by Louie et al investigated the impact of COVID-19 on 902 spine surgeons internationally. Since then, due to varying government responses and public health initiatives to the pandemic, individual countries and regions of the world have been affected differently. Therefore, this follow-up study aimed to assess how the COVID-19 impact on spine surgeons has changed 1 year later., Methods: A repeat, multi-dimensional, 90-item survey written in English was distributed to spine surgeons worldwide via email to the AO Spine membership who agreed to receive surveys. Questions were categorized into the following domains: demographics, COVID-19 observations, preparedness, personal impact, patient care, and future perceptions., Results: Basic respondent demographics, such as gender, age, home demographics, medical comorbidities, practice type, and years since training completion, were similar to those of the original 2020 survey. Significant differences between groups included reasons for COVID testing, opinions of media coverage, hospital unemployment, likelihood to be performing elective surgery, percentage of cases cancelled, percentage of personal income, sick leave, personal time allocation, stress coping mechanisms, and the belief that future guidelines were needed (P<.05)., Conclusion: Compared to baseline results collected at the beginning of the COVID-19 pandemic in 2020, significant differences in various domains related to COVID-19 perceptions, hospital preparedness, practice impact, personal impact, and future perceptions have developed. Follow-up assessment of spine surgeons has further indicated that telemedicine and virtual education are mainstays. Such findings may help to inform and manage expectations and responses to any future outbreaks., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Malnutrition is a common condition that may exacerbate many medical and surgical pathologies. However, few have studied the impact of malnutrition on surgical outcomes for patients undergoing surgery for metastatic disease of the spine. This study aims to evaluate the impact of malnutrition on perioperative complications and healthcare resource utilization following surgical treatment of spinal metastases. Methods: We conducted a retrospective cohort study using the 2011-2019 American College of Surgeons National Surgical Quality Improvement Program database. Adult patients with spinal metastases who underwent laminectomy, corpectomy, or posterior fusion for extradural spinal metastases were identified using the CPT, ICD-9-CM, and ICD-10-CM codes. The study population was divided into two cohorts: Nourished (preoperative serum albumin values ≥ 3.5 g/dL) and Malnourished (preoperative serum albumin values < 3.5 g/dL). We assessed patient demographics, comorbidities, intraoperative variables, postoperative adverse events (AEs), hospital LOS, discharge disposition, readmission, and reoperation. Multivariate logistic regression analyses were performed to identify the factors associated with a prolonged length of stay (LOS), AEs, non-routine discharge (NRD), and unplanned readmission. Results: Of the 1613 patients identified, 26.0% were Malnourished. Compared to Nourished patients, Malnourished patients were significantly more likely to be African American and have a lower BMI, but the age and sex were similar between the cohorts. The baseline comorbidity burden was significantly higher in the Malnourished cohort compared to the Nourished cohort. Compared to Nourished patients, Malnourished patients experienced significantly higher rates of one or more AEs (Nourished: 19.8% vs. Malnourished: 27.6%, p = 0.004) and serious AEs (Nourished: 15.2% vs. Malnourished: 22.6%, p < 0.001). Upon multivariate regression analysis, malnutrition was found to be an independent and associated with an extended LOS [aRR: 3.49, CI (1.97, 5.02), p < 0.001], NRD [saturated aOR: 1.76, CI (1.34, 2.32), p < 0.001], and unplanned readmission [saturated aOR: 1.42, CI (1.04, 1.95), p = 0.028]. Conclusions: Our study suggests that malnutrition increases the risk of postoperative complication, prolonged hospitalizations, non-routine discharges, and unplanned hospital readmissions. Further studies are necessary to identify the protocols that pre- and postoperatively optimize malnourished patients undergoing spinal surgery for metastatic spinal disease.

Introduction: The aim of this study was to investigate the impact of racial disparities on surgical outcomes for cervical spondylotic myelopathy (CSM)., Methods: Adult patients undergoing anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF) for CSM were identified from the 2016 to 019 National Inpatient Sample Database using the International Classification of Diseases codes. Patients were categorized based on approach (ACDF or PCDF) and race/ethnicity (White, Black, Hispanic). Patient demographics, comorbidities, operative characteristics, adverse events, and health care resource utilization were assessed. Multivariate logistic regression analyses were used to identify independent predictors of extended length of stay (LOS), nonroutine discharge (NRD), and exorbitant costs., Results: A total of 46,500 patients were identified, of which 36,015 (77.5%) were White, 7465 (16.0%) were Black, and 3020 (6.5%) were Hispanic. Black and Hispanic patients had a greater comorbidity burden compared to White patients (P = 0.001) and a greater incidence of any postoperative complication (P = 0.001). Healthcare resource utilization were greater in the PCDF cohort than the ACDF cohort and greater in Black and Hispanic patients compared to White patients (P < 0.001). Black and Hispanic patient race were significantly associated with extended hospital LOS ([Black] odds ratio [OR]: 2.24, P < 0.001; [Hispanic] OR: 1.64, P < 0.001) and NRD ([Black] OR: 2.33, P < 0.001; [Hispanic] OR: 1.49, P = 0.016). Among patients who underwent PCDF, Black race was independently associated with extended hospital LOS ([Black] OR: 1.77, P < 0.001; [Hispanic] OR: 1.47, P = 0.167) and NRD ([Black] OR: 1.82, P < 0.001; [Hispanic] OR: 1.38, P = 0.052)., Conclusions: Our study suggests that patient race may influence patient outcomes and healthcare resource utilization following ACDF or PCDF for CSM., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Study Design: This is a cross-sectional survey., Objective: The aim was to assess the reliability of a proposed novel classification system for thoracic disc herniations (TDHs)., Summary of Background Data: TDHs are complex entities varying substantially in many factors, including size, location, and calcification. To date, no comprehensive system exists to categorize these lesions., Methods: Our proposed system classifies 5 types of TDHs using anatomic and clinical characteristics, with subtypes for calcification. Type 0 herniations are small (≤40% of spinal canal) TDHs without significant spinal cord or nerve root effacement; type 1 are small and paracentral; type 2 are small and central; type 3 are giant (>40% of spinal canal) and paracentral; and type 4 are giant and central. Patients with types 1 to 4 TDHs have correlative clinical and radiographic evidence of spinal cord compression. Twenty-one US spine surgeons with substantial TDH experience rated 10 illustrative cases to determine the system's reliability. Interobserver and intraobserver reliability were determined using the Fleiss kappa coefficient. Surgeons were also surveyed to obtain consensus on surgical approaches for the various TDH types., Results: High agreement was found for the classification system, with 80% (range 62% to 95%) overall agreement and high interrater and intrarater reliability (kappa 0.604 [moderate to substantial agreement] and kappa 0.630 [substantial agreement], respectively). All surgeons reported nonoperative management of type 0 TDHs. For type 1 TDHs, most respondents (71%) preferred posterior approaches. For type 2 TDHs, responses were roughly equivalent for anterolateral and posterior options. For types 3 and 4 TDHs, most respondents (72% and 68%, respectively) preferred anterolateral approaches., Conclusions: This novel classification system can be used to reliably categorize TDHs, standardize description, and potentially guide the selection of surgical approach. Validation of this system with regard to treatment and clinical outcomes represents a line of future study., Competing Interests: J.S.U. receives consulting fees and royalties from NuVasive, Inc, and is a consultant for Misonix, Inc, and SI-BONE, Inc. J.D.T. receives consulting fees and royalties from NuVasive, Inc. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The present study utilized recently developed in-construct measurements in simulations of cervical deformity surgery in order to assess undercorrection and predict distal junctional kyphosis (DJK)., Methods: A retrospective review of a database of operative cervical deformity patients was analyzed for severe DJK and mild DJK. C2-lower instrumented vertebra (LIV) sagittal angle (SA) was measured postoperatively, and the correction was simulated in the preoperative radiograph in order to match the C2-LIV by using the planning software. Linear regression analysis that used C2 pelvic angle (CPA) and pelvic tilt (PT) determined the simulated PT that matched the virtual CPA. Linear regression analysis was used to determine the C2-T1 SA, C2-T4 SA, and C2-T10 SA that corresponded to DJK of 20° and cervical sagittal vertical axis (cSVA) of 40 mm., Results: Sixty-nine cervical deformity patients were included. Severe and mild DJK occurred in 11 (16%) and 22 (32%) patients, respectively; 3 (4%) required DJK revision. Simulated corrections demonstrated that severe and mild DJK patients had worse alignment compared to non-DJK patients in terms of cSVA (42.5 mm vs 33.0 mm vs 23.4 mm, p < 0.001) and C2-LIV SVA (68.9 mm vs 57.3 mm vs 36.8 mm, p < 0.001). Linear regression revealed the relationships between in-construct measures (C2-T1 SA, C2-T4 SA, and C2-T10 SA), cSVA, and change in DJK (all R > 0.57, p < 0.001). A cSVA of 40 mm corresponded to C2-T4 SA of 10.4° and C2-T10 SA of 28.0°. A DJK angle change of 10° corresponded to C2-T4 SA of 5.8° and C2-T10 SA of 20.1°., Conclusions: Simulated cervical deformity corrections demonstrated that severe DJK patients have insufficient corrections compared to patients without DJK. In-construct measures assess sagittal alignment within the fusion separate from DJK and subjacent compensation. They can be useful as intraoperative tools to gauge the adequacy of cervical deformity correction.

Objective: The rise of spinal surgery for ankylosing spondylitis (AS) necessitates balancing health care costs with quality patient care. Frailty has been independently associated with adverse outcomes and increased costs. This study investigates whether frailty is an independent predictor of poor outcomes after elective surgery for AS., Methods: Using the National Inpatient Sample (NIS) database, a retrospective study was conducted on adult patients with AS who underwent posterior spinal fusion for fracture between 2016 and 2019. Each patient was assigned a modified frailty index (mFI) score and categorized as prefrail (mFI = 0 or 1), moderately frail (mFI = 2), and highly frail (mFI≥3). Multivariate logistic regression analyses were used to identify independent predictors of extended length of stay, non-routine discharge (NRD), and exorbitant admission costs., Results: Of the 1910 patients, 35.3% were prefrail, 31.2% moderately frail, and 33.5% highly frail. Age was significantly different across groups (P < 0.001), and frailty was associated with increased comorbidities (P < 0.001). Mean length of stay (P = 0.007), NRD rate (P < 0.001), and mean cost of admission (P = 0.002) all significantly increased with increasing frailty. However, frailty was not an independent predictor of extended hospital stay, NRD, or higher costs on multivariate analysis. Instead, predictors included multiple adverse events, number of comorbidities, and race., Conclusions: While frailty in patients with AS is associated with older age, greater comorbidities, and increased adverse events, it was not an independent predictor of extended hospital stay, NRD, or higher hospital costs. Further research is required to understand the full impact of frailty on surgical outcomes and develop effective interventions., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Primary osseous neoplasms of the spine, including Ewing's sarcoma, osteosarcoma, chondrosarcoma, and chordoma, are rare tumors with significant morbidity and mortality. The present study aims to identify the prevalence and impact of racial disparities on management and outcomes of patients with these malignancies., Methods: The 2000 to 2020 Surveillance, Epidemiology, and End Results (SEER) Registry, a cancer registry, was retrospectively reviewed to identify patients with Ewing's sarcoma, osteosarcoma, chondrosarcoma, or chordoma of the vertebral column or sacrum/pelvis. Study patients were divided into race-based cohorts: White, Black, Hispanic, and Other. Demographics, tumor characteristics, treatment variables, and mortality were assessed., Results: 2,415 patients were identified, of which 69.8% were White, 5.8% Black, 16.1% Hispanic, and 8.4% classified as "Other". Tumor type varied significantly between cohorts, with osteosarcoma affecting a greater proportion of Black patients compared to the others (p < 0.001). A lower proportion of Black and Other race patients received surgery compared to White and Hispanic patients (p < 0.001). Utilization of chemotherapy was highest in the Hispanic cohort (p < 0.001), though use of radiotherapy was similar across cohorts (p = 0.123). Five-year survival (p < 0.001) and median survival were greatest in White patients (p < 0.001). Compared to non-Hispanic Whites, Hispanic (p < 0.001) and "Other" patients (p < 0.001) were associated with reduced survival., Conclusion: Race may be associated with tumor characteristics at diagnosis (including subtype, size, and site), treatment utilization, and mortality, with non-White patients having lower survival compared to White patients. Further studies are necessary to identify underlying causes of these disparities and solutions for eliminating them., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Study Design: Retrospective review of prospective, multicenter and international cohort study., Objective: To describe the effect of gender on HRQoL, clinical outcomes and survival for patients with spinal metastases treated with either surgery and/or radiation., Summary of Background Data: Gender differences in health-related outcomes are demonstrated in numerous studies, with women experiencing worse outcomes and receiving lower standards of care than men, however, the influence that gender has on low health-related quality of life (HRQoL) and clinical outcomes after spine surgery remains unclear., Methods: Patient demographic data, overall survival, treatment details, perioperative complications, and HRQoL measures including EQ-5D, pain NRS, the short form 36 version 2 (SF-36v2) and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0) were reviewed. Patients were stratified by sex, and a separate sensitivity analysis that excluded gender-specific cancers (i.e., breast, prostate, etc.) was performed., Results: The study cohort included 207 female and 183 male patients, with age, smoking status, and site of primary cancer being significantly different between the two cohorts (P<0.001). Both males and females experienced significantly improved SOSGOQ2.0, EQ-5D, and pain NRS scores at all study time points from baseline (P<0.001). Upon sensitivity analysis, (gender-specific cancers removed from analysis), the significant improvement in SOSGOQ physical, mental, and social subdomains and on SF-36 domains disappeared for females. Males experienced higher rates of postoperative complications. Kaplan-Meier survival analysis of both the overall and sensitivity analysis cohorts showed females lived longer than males after treatment (P=0.001 and 0.043, respectively)., Conclusion: Both males and females experienced significantly improved HRQoL scores after treatment, but females demonstrated longer survival and a lower complication rate. This study suggests that gender may be a prognostic factor in survival and clinical outcomes for patients undergoing treatment for spine metastases and should be taken into consideration when counseling patients accordingly., Competing Interests: Conflict of Interest: The authors report no conflicts of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction : Frailty has been shown to negatively influence patient outcomes across many disease processes, including in the cervical spondylotic myelopathy (CSM) population. The aim of this study was to assess the impact that frailty has on patients with CSM who undergo anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF). Materials and Methods : A retrospective cohort study was performed using the 2016-2019 national inpatient sample. Adult patients (≥18 years old) undergoing ACDF only or PCDF only for CSM were identified using ICD codes. The patients were categorized based on receipt of ACDF or PCDF and pre-operative frailty status using the 11-item modified frailty index (mFI-11): pre-Frail (mFI = 1), frail (mFI = 2), or severely frail (mFI ≥ 3). Patient demographics, comorbidities, operative characteristics, perioperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analyses were used to identify independent predictors of extended length of stay (LOS) and non-routine discharge (NRD). Results : A total of 37,990 patients were identified, of which 16,665 (43.9%) were in the pre-frail cohort, 12,985 (34.2%) were in the frail cohort, and 8340 (22.0%) were in the severely frail cohort. The prevalence of many comorbidities varied significantly between frailty cohorts. Across all three frailty cohorts, the incidence of AEs was greater in patients who underwent PCDF, with dysphagia being significantly more common in patients who underwent ACDF. Additionally, the rate of adverse events significantly increased between ACDF and PCDF with respect to increasing frailty ( p < 0.001). Regarding healthcare resource utilization, LOS and rate of NRD were significantly greater in patients who underwent PCDF in all three frailty cohorts, with these metrics increasing with frailty in both ACDF and PCDF cohorts (LOS: p < 0.001); NRD: p < 0.001). On a multivariate analysis of patients who underwent ACDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.39, p < 0.001; (severely frail) OR: 2.25, p < 0.001] and NRD [(frail) OR: 1.49, p < 0.001; (severely frail) OR: 2.22, p < 0.001]. Similarly, in patients who underwent PCDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.58, p < 0.001; (severely frail) OR: 2.45, p < 0.001] and NRD [(frail) OR: 1.55, p < 0.001; (severely frail) OR: 1.63, p < 0.001]. Conclusions : Our study suggests that preoperative frailty may impact outcomes after surgical treatment for CSM, with more frail patients having greater health care utilization and a higher rate of adverse events. The patients undergoing PCDF ensued increased health care utilization, compared to ACDF, whereas severely frail patients undergoing PCDF tended to have the longest length of stay and highest rate of non-routine discharge. Additional prospective studies are necessary to directly compare ACDF and PCDF in frail patients with CSM.

Objective: Intramedullary spinal cord tumors (IMSCTs) are rare tumors with heterogeneous presentations and natural histories that complicate their management. Standardized guidelines are lacking on when to surgically intervene and the appropriate aggressiveness of resection, especially given the risk of new neurological deficits following resection of infiltrative tumors. Here, the authors present the results of a modified Delphi method using input from surgeons experienced with IMSCT removal to construct a framework for the operative management of IMSCTs based on the clinical, radiographic, and tumor-specific characteristics., Methods: A modified Delphi technique was conducted using a group of 14 neurosurgeons experienced in IMSCT resection. Three rounds of written correspondence, surveys, and videoconferencing were carried out. Participants were queried about clinical and radiographic criteria used to determine operative candidacy and guide decision-making. Members then completed a final survey indicating their choice of observation or surgery, choice of resection strategy, and decision to perform duraplasty, in response to a set of patient- and tumor-specific characteristics. Consensus was defined as ≥ 80% agreement, while responses with 70%-79% agreement were defined as agreement., Results: Thirty-six total characteristics were assessed. There was consensus favoring surgical intervention for patients with new-onset myelopathy (86% agreement), chronic myelopathy (86%), or progression from mild to disabling numbness (86%), but disagreement for patients with mild numbness or chronic paraplegia. Age was not a determinant of operative candidacy except among frail patients, who were deemed more suitable for observation (93%). Well-circumscribed (93%) or posteriorly located tumors reaching the surface (86%) were consensus surgical lesions, and participants agreed that the presence of syringomyelia (71%) and peritumoral T2 signal change (79%) were favorable indications for surgery. There was consensus that complete loss of transcranial motor evoked potentials with a 50% decrease in the D-wave amplitude should halt further resection (93%). Preoperative symptoms seldom influenced choice of resection strategy, while a distinct cleavage plane (100%) or visible tumor-cord margins (100%) strongly favored gross-total resection., Conclusions: The authors present a modified Delphi technique highlighting areas of consensus and agreement regarding surgical management of IMSCTs. Although not intended as a substitute for individual clinical decision-making, the results can help guide care of these patients. Additionally, areas of controversy meriting further investigation are highlighted.

Study Design: Retrospective cohort., Objective: To radiographically evaluate Craniovertebral junction (CVJ) tuberculosis infection pathogenesis and to propose a modification to the Lifeso classification., Methods: A cohort of patients with radiologically or microbiologically identified CVJ tuberculosis treated at a single tertiary referral center in a TB endemic area was queried for characteristics about clinical presentation, treatment, and radiographic evidence of bone destruction and abscess formation were included. Disease was classified according to the Lifeso grading system and bony lesions were classified as either type 1 (preservation of underlying structure) or type 2 (damage of underlying structure)., Results: 52 patients were identified (mean age 28.5 ± 13.4yr, 48% male; 14% with a prior history of tuberculosis). All presented with neck pain at presentation, 29% with rotatory pain, and 37% with myelopathy. Comparison by Lifeso type showed Lifeso III lesions had longer symptom durations ( P = .03) and more commonly had periarticular or predental abscess formation ( P < .05), spinal cord compression ( P < .01), and more commonly involved the C2 body and atlanto-dental joint. Underlying bony destruction was more common for lesions of the lateral atlantoaxial joints and atlanto-dental joints in Lifeso III cases than in either Lifeso I or II (all P < .05)., Conclusions: The radiologic findings of the present series suggest CVJ TB infection may originate in the periarticular fascia with subsequent invasion into the adjacent atlanto-dental and lateral atlantoaxial joints in later disease. To reflect this proposed etiology, we present a modified Lifeso classification to describe the radiologic pathogenesis of CVJ TB.

Background: Patients undergoing surgery for adult spinal deformity (ASD) are often elderly, frail, and at elevated risk of adverse events perioperatively, with proximal junctional failure (PJF) occurring relatively frequently. Currently, the specific role of frailty in potentiating this outcome is poorly defined., Purpose: To determine if the benefits of optimal realignment in ASD, with respect to the development of PJF, can be offset by increasing frailty., Study Design: Retrospective cohort., Materials and Methods: Operative ASD patients (scoliosis >20°, SVA>5 cm, pelvic tilt>25°, or TK>60°) fused to the pelvis or below with available baseline and 2-year (2Y) radiographic and HRQL data were included. The Miller Frailty Index (FI) was used to stratify patients into 2 categories: Not Frail (FI <3) and Frail (>3). Proximal Junctional Failure (PJF) was defined using the Lafage criteria. "Matched" and "unmatched" refers to ideal age-adjusted alignment postoperatively. Multivariable regression determined the impact of frailty on the development of PJF., Results: Two hundred eighty-four ASD patients met inclusion criteria [62.2yrs±9.9, 81%F, BMI: 27.5 kg/m 2 ±5.3, ASD-FI: 3.4±1.5, Charlson Comorbidity Index (CCI): 1.7±1.6]. Forty-three percent of patients were characterized as Not Frail (NF) and 57% were characterized as Frail (F). PJF development was lower in the NF group compared with the F group (7% vs . 18%; P =0.002). F patients had 3.2 × higher risk of PJF development compared to NF patients (OR: 3.2, 95% CI: 1.3-7.3, P =0.009). Controlling for baseline factors, F unmatched patients had a higher degree of PJF (OR: 1.4, 95% CI:1.02-1.8, P =0.03); however, with prophylaxis, there was no increased risk. Adjusted analysis shows F patients, when matched postoperatively in PI-LL, had no significantly higher risk of PJF., Conclusions: An increasingly frail state is significantly associated with the development of PJF after corrective surgery for ASD. Optimal realignment may mitigate the impact of frailty on eventual PJF. Prophylaxis should be considered in frail patients who do not reach ideal alignment goals., Competing Interests: A.J. S.: AAOS: board or committee member. Journal of Bone and Joint Surgery —American: Editorial or governing board. North American Spine Society: board or committee member. Spine: Editorial or governing board. Springer: Publishing royalties, financial or material support. Wolters Kluwer Health - Lippincott Williams & Wilkins: publishing royalties, financial or material support. D.S.: Baxter: paid consultant. DePuy, A Johnson & Johnson Company: paid consultant. K2M: paid consultant. Medtronic: paid consultant. Nuvasive: paid consultant. Stryker: paid consultant. J.S.S.: Alphatec Spine: stock or stock options. Carlsmed: paid consultant. Cerapedics: paid consultant. DePuy: research support. DePuy, A Johnson & Johnson Company: paid consultant. Journal of Neurosurgery Spine: editorial or governing board. Neurosurgery: editorial or governing board. Nuvasive: IP royalties; paid consultant; research support; stock or stock options. Operative Neurosurgery: editorial or governing board. Scoliosis Research Society: board or committee member. SeaSpine: paid consultant. Spine Deformity: editorial or governing board. Stryker: paid consultant. Thieme: publishing royalties, financial or material support. Zimmer: IP royalties; paid consultant. R.L.: Carlsmed: paid consultant. V.L.: Alphatec Spine: paid consultant. DePuy, A Johnson & Johnson Company: paid presenter or speaker. European Spine Journal: editorial or governing board. Globus Medical: paid consultant. International Spine Study Group: board or committee member. Nuvasive: IP royalties. Scoliosis Research Society: board or committee member. Stryker: paid presenter or speaker. P.G.P.: Cerapedics: other financial or material support. Cervical Scoliosis Research Society: research support. Globus Medical: paid presenter or speaker. Medtronic: paid consultant. Royal Biologics: paid consultant. Spine: editorial or governing board. Spinevision: other financial or material support. SpineWave: paid consultant. Terumo: paid consultant. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Objectives: Sacrectomy is often the treatment of choice to provide the greatest chance of progression-free and overall survival for patients with primary malignant bone tumors of the sacrum. After midsacrectomy, the stability of the sacropelvic interface is diminished, resulting in insufficiency fractures. Traditional stabilization involves lumbopelvic fixation but subjects normal mobile segments to fusion. The purpose of this study was to determine whether standalone intrapelvic fixation is a safe adjunct to midsacrectomy, avoiding both sacral insufficiency fractures and the morbidity of instrumenting into the mobile spine., Methods: A retrospective study identified all patients who underwent resection of sacral tumors at 2 comprehensive cancer centers between June 2020 and July 2022. Demographic, tumor-specific, operative characteristics and outcome data were collected. The primary outcome was presence of sacral insufficiency fractures. A retrospective data set of patients undergoing midsacrectomy without hardware placement was collected as a control., Results: Nine patients (5 male, 4 female), median age 59 years, underwent midsacrectomy with concomitant placement of standalone pelvic fixation. No patients developed insufficiency fractures during the 216 days of clinical and 207 days of radiographic follow-up. There were no adverse events attributable to the addition of standalone pelvic fixation. In our historical cohort of partial sacrectomies without stabilization, there were 4/25 patients (16%) with sacral insufficiency fractures. These fractures appeared between 0 and 5 months postoperatively., Conclusion: A novel standalone intrapelvic fixation after partial sacrectomy is a safe adjunct to prevent postoperative sacral insufficiency fractures in patients undergoing midsacrectomy for tumor. Such a technique may allow for long-term sacropelvic stability without sacrificing mobile lumbar segments., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: Resource allocation to research activities is challenging and there is limited evidence to justify decisions. Members of AO Spine were surveyed to understand the research practices and needs of spine surgeons worldwide., Methods: An 84-item survey was distributed to the AO Spine community in September of 2020. Respondent demographics and insights regarding research registries, training and education, mentorship, grants and financial support, and future directions were collected. Responses were anonymous and compared among regions., Results: A total of 333 spine surgeons representing all geographic regions responded; 52.3% were affiliated with an academic/university hospital, 91.0% conducted clinical research, and 60.9% had 5+ years of research experience. There was heterogeneity among research practices and needs across regions. North American respondents had more research experience ( P = .023), began conducting research early on ( P < .001), had an undergraduate science degree ( P < .001), and were more likely to have access to a research coordinator or support staff ( P = .042) compared to other regions. While all regions expressed having the same challenges in conducting research, Latin America, and Middle East/Northern Africa respondents were less encouraged to do research ( P < .001). Despite regional differences, there was global support for research registries and research training and education., Conclusion: To advance spine care worldwide, spine societies should establish guidelines, conduct studies on pain management, and support predictive analytic modeling. Tailoring local/regional programs according to regional needs is advised. These results can assist spine societies in developing long-term research strategies and provide justified rationale to governments and funding agencies.

Objective: The Hospital Frailty Risk Score (HFRS) is a metric that measures frailty among patients in large national datasets using ICD-10 codes. While other metrics have been utilized to demonstrate the association between frailty and poor outcomes in spine oncology, none have examined the HFRS. The aim of this study was to investigate the impact of frailty using the HFRS on complications, length of stay, cost of admission, and discharge disposition in patients undergoing surgery for primary tumors of the spinal cord and meninges., Methods: A retrospective cohort study was performed using the Nationwide Inpatient Sample database from 2016 to 2018. Adult patients undergoing surgery for primary tumors of the spinal cord and meninges were identified using ICD-10-CM codes. Patients were categorized into 2 cohorts based on HFRS score: Non-Frail (HFRS<5) and Frail (HFRS≥5). Patient characteristics, treatment, perioperative complications, LOS, discharge disposition, and cost of admission were assessed., Results: Of the 5955 patients identified, 1260 (21.2%) were Frail. On average, the Frail cohort was nearly 8 years older ( P < .001 ) and experienced more postoperative complications ( P = .001 ). The Frail cohort experienced longer LOS ( P < .001 ), a higher rate of non-routine discharge ( P = .001 ), and a greater mean cost of admission ( P < .001 ). Frailty was found to be an independent predictor of extended LOS ( P < .001 ) and non-routine discharge ( P < .001 )., Conclusion: Our study is the first to use the HFRS to assess the impact of frailty on patients with primary spinal tumors. We found that frailty was associated with prolonged LOS, non-routine discharge, and increased hospital costs.

Background: Patients undergoing surgical procedures for spinal tumors are vulnerable to major adverse events (AEs) and death in the postoperative period. Shared decision making and preoperative optimization of outcomes require accurate risk estimation., Objective: To develop and validate a risk index to predict short-term major AEs after spinal tumor surgery., Methods: Prospectively collected data from multiple medical centers affiliated with the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2020 were reviewed. Multiple logistic regression was used to assess sociodemographic, tumor-related, and surgery-related factors in the derivation cohort. The spinal tumor surgery risk index (STSRI) was built based on the resulting scores. The STSRI was internally validated using a subgroup of patients from the American College of Surgeons National Surgical Quality Improvement Program database and externally validated using a cohort from a single tertiary center., Results: In total, 14 982 operations were reviewed and 4556 (16.5%) major AEs occurred within 30 days after surgery, including 209 (4.5%) deaths. 22 factors were independently associated with major AEs or death and were included in the STSRI. Using the internal and external validation cohorts, the STSRI produced an area under the curve of 0.86 and 0.82, sensitivity of 80.1% and 79.7%, and specificity of 74.3% and 73.7%, respectively. The STSRI, which is freely available, outperformed the modified frailty indices, the American Society of Anesthesiologists classification, and the American College of Surgeons risk calculator., Conclusion: In patients undergoing surgery for spinal tumors, the STSRI showed the highest predictive accuracy for major postoperative AEs and death compared with other current risk predictors., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Study Design: A cross-sectional study was performed using the National Institutes of Health All of Us survey database., Objective: The aim of this study was to assess socioeconomic and racial disparities in the perception of personal health, health literacy, and healthcare access among spine oncology patients., Summary of Background Data: Racial, ethnic, and socioeconomic disparities in health literacy and perception of health status have been described for many disease processes. However, few studies have assessed the prevalence of these disparities among spine oncology patients., Methods: Adult spine oncology patients, identified using ICD-9/10-CM codes, were categorized by race/ethnicity: White/Caucasian (WC), Black/African-American (BAA), and Non-White Hispanic (NWH). Demographics and socioeconomic status were assessed. Questionnaire responses regarding baseline health status, perception of health status, health literacy, and barriers to healthcare were compared., Results: Of the 1,175 patients identified, 207 (17.6%) were BAA, 267 (22.7%) were NWH, and 701 (59.7%) were WC. Socioeconomic status varied among cohorts, with WC patients reporting higher levels of education ( P<0.001 ), annual income greater than $50K ( P<0.001 ), and home ownership ( P<0.001 ). BAA and NWH patients reported greater rates of 7-day "Severe fatigue" ( P<0.001 ) and "10/10 pain" ( P<0.001 ) and lower rates of "Completely" able to perform everyday activities ( P<0.001 ). WC patients had a higher response rate for "Excellent/Very Good" regarding their own general health ( P<0.001 ) and quality ( P<0.001 ). The WC cohort had a significantly higher proportion of patients responding "Never" when assessing difficulty understanding ( P<0.001 ) and needing assistance with health materials ( P<0.001 ). BAA and NWH were significantly less likely to report feeling "Extremely" confident with medical forms ( P<0.001 ). BAA and NWH had significantly higher response rates to feeling "Somewhat Worried" about healthcare costs ( P<0.001 ) and with delaying medical care given "Can't Afford Co-pay" ( P<0.001 )., Conclusion: We identified disparities in perception of health status, literacy, and access among spine oncology patients., Level of Evidence: 4., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Intramedullary spinal cord (IMSC) subependymomas are rare World Health Organization grade 1 ependymal tumors. The potential presence of functional neural tissue within the tumor and poorly demarcated planes presents a risk to resection. Anticipating a subependymoma on preoperative imaging can inform surgical decision-making and improve patient counseling. Here, we present our experience recognizing IMSC subependymomas on preoperative magnetic resonance imaging (MRI) based on a distinctive characteristic termed the "ribbon sign.", Methods: We retrospectively reviewed preoperative MRIs of patients presenting with IMSC tumors at a large tertiary academic institution between April 2005 and January 2022. The diagnosis was confirmed histologically. The "ribbon sign" was defined as a ribbon-like structure of T2 isointense spinal cord tissue interwoven between regions of T2 hyperintense tumor. The ribbon sign was confirmed by an expert neuroradiologist., Results: MRIs from 151 patients were reviewed, including 10 patients with IMSC subependymomas. The ribbon sign was demonstrated on 9 (90%) patients with histologically proven subependymomas. Other tumor types did not display the ribbon sign., Conclusion: The ribbon sign is a potentially distinctive imaging feature of IMSC subependymomas and indicates the presence of spinal cord tissue between eccentrically located tumors. Recognition of the ribbon sign should prompt clinicians to consider a diagnosis of subependymoma, aiding the neurosurgeon in planning the surgical approach and adjusting the surgical outcome expectation. Consequently, the risks and benefits of gross-versus subtotal resection for palliative debulking should be carefully considered and discussed with patients., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Study Design: International survey., Objectives: To assess variability in the treatment practices for spinal metastases as a function of practice setting, surgical specialty, and fellowship training among an international group of spine surgeons., Methods: An anonymous internet-based survey was disseminated to the AO Spine membership. The questionnaire contained items on practice settings, fellowship training, indications used for spinal metastasis surgery, surgical strategies, multidisciplinary team use, and postoperative follow-up priorities and practice., Results: 341 gave complete responses to the survey with 76.3% identifying spinal oncology as a practice focus and 95.6% treating spinal metastases. 80% use the Spinal Instability Neoplastic Score (SINS) to guide instrumentation decision-making and 60.7% recruit multidisciplinary teams for some or all cases. Priorities for postoperative follow-up are adjuvant radiotherapy (80.9%) and systemic therapy (74.8%). Most schedule first follow-up within 6 weeks of surgery (62.2%). Significant response heterogeneity was seen when stratifying by practice in an academic or university-affiliated center, practice in a cancer center, completion of a spine oncology fellowship, and self-identification as a tumor specialist. Respondents belonging to any of these categories were more likely to utilize SINS ( P < .01-.02), recruit assistance from plastic surgeons (all P < .01), and incorporate radiation oncologists in postoperative care ( P < .01-.03)., Conclusions: The largest variability in practice strategies is based upon practice setting, spine tumor specialization, and completion of a spine oncology fellowship. These respondents were more likely to use evidenced-based practices. However, the response variability indicates the need for consensus building, particularly for postoperative spine metastasis care pathways and multidisciplinary team use.

Study Design: International multicenter prospective observational cohort study on patients undergoing radiation +/- surgical intervention for the treatment of symptomatic spinal metastases., Objectives: To investigate the association between the total Spinal Instability Neoplastic Score (SINS), individual SINS components and PROs., Methods: Data regarding patient demographics, diagnostics, treatment, and PROs (SF-36, SOSGOQ, EQ-5D) was collected at baseline, 6 weeks, and 12 weeks post-treatment. The SINS was assessed using routine diagnostic imaging. The association between SINS, PRO at baseline and change in PROs was examined with the Spearmans rank test., Results: A total of 307 patients, including 174 patients who underwent surgery+/- radiotherapy and 133 patients who underwent radiotherapy were eligible for analyses. In the surgery+/- radiotherapy group, 18 (10.3%) patients with SINS score between 0-6, 118 (67.8%) with a SINS between 7-12 and 38 (21.8%) with a SINS between 13-18, as compared to 55 (41.4%) SINS 0-6, 71(53.4%) SINS 7-12 and 7 (5.2%) SINS 13-18 in the radiotherapy alone group. At baseline, the total SINS and the presence of mechanical pain was significantly associated with the SOSGOQ pain domain (r = -0.519, P < 0.001) and the NRS pain score (r = 0.445, P < 0.001) for all patients. The presence of mechanical pain demonstrated to be moderately associated with a positive change in PROs at 12 weeks post-treatment., Conclusion: Spinal instability, as defined by the SINS, was significantly correlated with PROs at baseline and change in PROs post-treatment. Mechanical pain, as a single SINS component, showed the highest correlations with PROs.

Study Design: Observational cohort study., Objective: The aim of this study was to investigate the association between safety-net hospital (SNH) status and hospital length of stay (LOS), cost, and discharge disposition in patients undergoing surgery for metastatic spinal column tumors., Summary of Background Data: SNHs serve a high proportion of Medicaid and uninsured patients. However, few studies have assessed the effects of SNH status on outcomes after surgery for metastatic spinal column tumors., Patients and Methods: This study was performed using the 2016-2019 Nationwide Inpatient Sample database. All adult patients undergoing metastatic spinal column tumor surgeries, identified using ICD-10-CM coding, were stratified by SNH status, defined as hospitals in the top quartile of Medicaid/uninsured coverage burden. Hospital characteristics, demographics, comorbidities, intraoperative variables, postoperative complications, and outcomes were assessed. Multivariable analyses identified independent predictors of prolonged LOS (>75th percentile of cohort), nonroutine discharge, and increased cost (>75th percentile of cohort)., Results: Of the 11,505 study patients, 24.0% (n = 2760) were treated at an SNH. Patients treated at SNHs were more likely to be Black-identifying, male, and lower income quartile. A significantly greater proportion of patients in the non-SNH (N-SNH) cohort experienced any postoperative complication [SNH: 965 (35.0%) vs . N-SNH: 3535 (40.4%), P = 0.021]. SNH patients had significantly longer LOS (SNH: 12.3 ± 11.3 d vs . N-SNH: 10.1 ± 9.5 d, P < 0.001), yet mean total costs (SNH: $58,804 ± 39,088 vs . N-SNH: $54,569 ± 36,781, P = 0.055) and nonroutine discharge rates [SNH: 1330 (48.2%) vs . N-SNH: 4230 (48.4%), P = 0.715) were similar. On multivariable analysis, SNH status was significantly associated with extended LOS [odds ratio (OR): 1.41, P = 0.009], but not nonroutine discharge disposition (OR: 0.97, P = 0.773) or increased cost (OR: 0.93, P = 0.655)., Conclusions: Our study suggests that SNHs and N-SNHs provide largely similar care for patients undergoing metastatic spinal tumor surgeries. Patients treated at SNHs may have an increased risk of prolonged hospitalizations, but comorbidities and complications likely contribute greater to adverse outcomes than SNH status alone., Level of Evidence: 3., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective cohort study., Objective: To assess the impact of race on complications following spinal tumor surgery., Methods: Adults with cancer who underwent spine tumor surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program datasets from 2012 to 2016. Clavien-Dindo Grade I-II (minor complications) and Clavien-Dindo Grade III-V (major complications including 30-day mortality) complications were compared between non-Hispanic Whites (NHW) and Black patients. A multivariable analysis was also conducted., Results: Of 1,226 identified patients, 85.9% were NHW (n = 1,053) and 14.1% were Black (n = 173). The overall rate of Grade I-II complications was 16.2%; 15.1% for NHW patients and 23.1% for Black patients ( P = .008). On multivariable analysis, Black patients had significantly higher odds of having a minor complication (OR 1.87; 95% CI, 1.16-3.01; P = .010). On the other hand, the overall rate of Grade III-V complications was 13.3%; 12.5% for NHW patients and 16.2% for Black patients ( P = .187). On multivariable analysis, Black race was not independently associated with major complications (OR 1.26; 95% CI, 0.71-2.23; P = .430). Median length of stay was 8 days (IQR 5-13) for NHW patients and 10 days (IQR 6-15) for Black patients ( P = .011)., Conclusion: Black patients who underwent metastatic spinal tumor surgery were at a significantly increased risk of perioperative morbidity compared to NHW patients independent of baseline and operative characteristics. Major complications did not differ between groups. Race should be further studied in the context of metastatic spine disease to improve our understanding of these disparities.

Objective: Frailty has been shown to affect patient outcomes after medical and surgical interventions. The Hospital Frailty Risk Score (HFRS) is a growing metric used to assess patient frailty using International Classification of Diseases, Tenth Revision codes. The goal of this study was to investigate the impact of frailty, assessed by HFRS, on health care resource utilization and outcomes in patients undergoing surgery for spinal meningiomas., Methods: A retrospective cohort study was performed using the 2016-2019 National Inpatient Sample database. Adult patients with benign or malignant spinal meningiomas, identified using International Classification of Diseases, Tenth Revision, Clinical Modification codes, were stratified by HFRS: low frailty (HFRS <5) and intermediate-high frailty (HFRS ≥5). Patient demographics, hospital characteristics, comorbidities, procedural variables, adverse events, length of stay (LOS), discharge disposition, and cost of admission were assessed. Multivariate regression analysis was used to identify predictors of increased LOS, discharge disposition, and cost., Results: Of the 3345 patients, 530 (15.8%) had intermediate-high frailty. The intermediate-high cohort was significantly older (P < 0.001). More patients in the intermediate-high cohort had ≥3 comorbidities (P < 0.001). In addition, a greater proportion of patients in the intermediate-high cohort experienced ≥1 perioperative adverse events (P < 0.001). Intermediate-high patients experienced greater mean LOS (P < 0.001) and accrued greater costs (P < 0.001). A greater proportion of intermediate-high patients had nonroutine discharges (P < 0.001). On multivariate analysis, increased HFRS (≥5) was independently associated with extended LOS (adjusted odds ratio [aOR], 3.04; P < 0.001), nonroutine discharge (aOR, 1.98; P = 0.006), and increased costs (aOR, 2.39; P = 0.004)., Conclusions: Frailty may be associated with increased health care resource utilization in patients undergoing surgery for spinal meningiomas., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Study Design: International survey., Objectives: C5 palsy (C5P) is a neurological complication affecting 5-10% of patients after cervical decompression surgery. Most cases improve with conservative treatment; however, nearly 20% of patients may be left with residual deficits. Guidelines are lacking on C5P management and timing of surgical intervention. Therefore, we sought to survey peripheral nerve surgeons on their management of C5P., Methods: An online survey was distributed centered around a patient with C5P after posterior cervical decompression and fusion. Questions included surgeon demographics, diagnostic modalities, and timing and choice of operation. Responses were summarized and the chi-squared and Kruskal-Wallis H tests were used to examine differences across specialties., Results: A total of 154 surgeons responded to the survey, of which 59 (38%) indicated that they manage C5P cases. Average time prior to operating was 4.5 ± 2.2 months for complete injuries and 6.6 ± 3.2 months for partial injuries, with neurosurgeons significantly more likely to wait longer periods for complete ( P = .01) and partial injuries ( P = .03). Foraminotomies were selected by 19% of surgeons, while 92% selected nerve transfers. Transfer of the ulnar nerve to the musculocutaneous nerve was the most common choice (81%), followed by transfer of the radial nerve to the axillary nerve (58%)., Conclusion: Consensus exists among peripheral nerve surgeons on the use of nerve transfers for surgical treatment in cases with severe motor weakness failing to improve. Most surgeons advocate for early intervention in complete injuries. Disagreement concerns the type of nerve transfer employed, timing of surgery, and efficacy of foraminotomy., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: The purpose of this study was to analyze risk factors for sacral fracture following noninstrumented partial sacral amputation for en bloc chordoma resection., Methods: A multicenter retrospective chart review identified patients who underwent noninstrumented partial sacral amputation for en bloc chordoma resection with pre- and postoperative imaging. Hounsfield units (HU) were measured in the S1 level. Sacral amputation level nomenclature was based on the highest sacral level with bone removed (e.g., S1 foramen amputation at the S1-2 vestigial disc is an S2 sacral amputation). Variables collected included basic demographics, patient comorbidities, surgical approach, preoperative radiographic details, neoadjuvant and adjuvant radiation therapy, and postoperative sacral fracture data., Results: A total of 101 patients (60 men, 41 women) were included; they had an average age of 69 years, BMI of 29 kg/m2, and follow-up of 60 months. The sacral amputation level was S1 (2%), S2 (37%), S3 (44%), S4 (9%), and S5 (9%). Patients had a posterior-only approach (77%) or a combined anterior-posterior approach (23%), with 10 patients (10%) having partial sacroiliac (SI) joint resection. Twenty-seven patients (27%) suffered a postoperative sacral fracture, all occurring between 1 and 7 months after the index surgery. Multivariable logistic regression analysis demonstrated S1 or S2 sacral amputation level (p = 0.001), combined anterior-posterior approach (p = 0.0064), and low superior S1 HU (p = 0.027) to be independent predictors of sacral fracture. The fracture rate for patients with superior S1 HU < 225, 225-300, and > 300 was 38%, 15%, and 9%, respectively. An optimal superior S1 HU cutoff of 300 was found to maximize sensitivity (89%) and specificity (42%) in predicting postamputation sacral fracture. In addition, the fracture rate for patients who underwent partial SI joint resection was 100%., Conclusions: Patients with S1 or S2 partial sacral amputations, a combined anterior-posterior surgical approach, low superior S1 HU, and partial SI joint resection are at higher risk for postoperative sacral fracture following en bloc chordoma resection and should be considered for spinopelvic instrumentation at the index procedure.

Objective: Infuse bone graft is a widely used osteoinductive adjuvant; however, the simple collagen sponge scaffold used in the implant has minimal inherent osteoinductive properties and poorly controls the delivery of the adsorbed recombinant human bone morphogenetic protein-2 (rhBMP-2). In this study, the authors sought to create a novel bone graft substitute material that overcomes the limitations of Infuse and compare the ability of this material with that of Infuse to facilitate union following spine surgery in a clinically translatable rat model of spinal fusion., Methods: The authors created a polydopamine (PDA)-infused, porous, homogeneously dispersed solid mixture of extracellular matrix and calcium phosphates (BioMim-PDA) and then compared the efficacy of this material directly with Infuse in the setting of different concentrations of rhBMP-2 using a rat model of spinal fusion. Sixty male Sprague Dawley rats were randomly assigned to each of six equal groups: 1) collagen + 0.2 µg rhBMP-2/side, 2) BioMim-PDA + 0.2 µg rhBMP-2/side, 3) collagen + 2.0 µg rhBMP-2/side, 4) BioMim-PDA + 2.0 μg rhBMP-2/side, 5) collagen + 20 µg rhBMP-2/side, and 6) BioMim-PDA + 20 µg rhBMP-2/side. All animals underwent posterolateral intertransverse process fusion at L4-5 using the assigned bone graft. Animals were euthanized 8 weeks postoperatively, and their lumbar spines were analyzed via microcomputed tomography (µCT) and histology. Spinal fusion was defined as continuous bridging bone bilaterally across the fusion site evaluated via µCT., Results: The fusion rate was 100% in all groups except group 1 (70%) and group 4 (90%). Use of BioMim-PDA with 0.2 µg rhBMP-2 led to significantly greater results for bone volume (BV), percentage BV, and trabecular number, as well as significantly smaller trabecular separation, compared with the use of the collagen sponge with 2.0 µg rhBMP-2. The same results were observed when the use of BioMim-PDA with 2.0 µg rhBMP-2 was compared with the use of the collagen sponge with 20 µg rhBMP-2., Conclusions: Implantation of rhBMP-2-adsorbed BioMim-PDA scaffolds resulted in BV and bone quality superior to that afforded by treatment with rhBMP-2 concentrations 10-fold higher implanted on a conventional collagen sponge. Using BioMim-PDA (vs a collagen sponge) for rhBMP-2 delivery could significantly lower the amount of rhBMP-2 required for successful bone grafting clinically, improving device safety and decreasing costs.

Purpose: The Hospital Frailty Risk Score (HFRS) is a frailty-identifying metric developed using ICD-10-CM codes. While other studies have examined frailty in adult spinal deformity (ASD), the HFRS has not been assessed in this population. The aim of this study was to utilize the HFRS to investigate the impact of frailty on outcomes in ASD patients undergoing posterior spinal fusion (PSF)., Methods: A retrospective study was performed using the 2016-2019 National Inpatient Sample database. Adults with ASD undergoing elective PSF were identified using ICD-10-CM codes. Patients were categorized into HFRS-based frailty cohorts: Low (HFRS < 5) and Intermediate-High (HFRS ≥ 5). Patient demographics, comorbidities, intraoperative variables, and outcomes were assessed. Multivariate regression analyses were used to determine whether HFRS independently predicted extended length of stay (LOS), non-routine discharge, and increased cost., Results: Of the 7500 patients identified, 4000 (53.3%) were in the Low HFRS cohort and 3500 (46.7%) were in the Intermediate-High HFRS cohort. On average, age increased progressively with increasing HFRS scores (p < 0.001). The frail cohort experienced more postoperative adverse events (p < 0.001), greater LOS (p < 0.001), accrued greater admission costs (p < 0.001), and had a higher rate of non-routine discharge (p < 0.001). On multivariate analysis, Intermediate-High HFRS was independently associated with extended LOS (OR: 2.58, p < 0.001) and non-routine discharge (OR: 1.63, p < 0.001), though not increased admission cost (OR: 1.01, p = 0.929)., Conclusion: Our study identified HFRS to be significantly associated with prolonged hospitalizations and non-routine discharge. Other factors that were found to be associated with increased healthcare resource utilization include age, Hispanic race, West hospital region, large hospital size, and increasing number of AEs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Frailty has not been clearly defined in the context of spinal metastatic disease (SMD). Given this, the objective of this study was to better understand how members of the international AO Spine community conceptualize, define, and assess frailty in SMD., Methods: The AO Spine Knowledge Forum Tumor conducted an international cross-sectional survey of the AO Spine community. The survey was developed using a modified Delphi technique and was designed to capture preoperative surrogate markers of frailty and relevant postoperative clinical outcomes in the context of SMD. Responses were ranked using weighted averages. Consensus was defined as ≥ 70% agreement among respondents., Results: Results were analyzed for 359 respondents, with an 87% completion rate. Study participants represented 71 countries. In the clinical setting, most respondents informally assess frailty and cognition in patients with SMD by forming a general perception based on clinical condition and patient history. Consensus was attained among respondents regarding the association between 14 preoperative clinical variables and frailty. Severe comorbidities, extensive systemic disease burden, and poor performance status were most associated with frailty. Severe comorbidities associated with frailty included high-risk cardiopulmonary disease, renal failure, liver failure, and malnutrition. The most clinically relevant outcomes were major complications, neurological recovery, and change in performance status., Conclusions: The respondents recognized that frailty is important, but they most commonly evaluate it based on general clinical impressions rather than using existing frailty tools. The authors identified numerous preoperative surrogate markers of frailty and postoperative clinical outcomes that spine surgeons perceived as most relevant in this population.