Study Design Narrative Review. Objectives To summarize the scientific contributions generated from the AO Spine Knowledge Forum Tumor (AOSKFT) databases, focusing on primary spine tumors, and highlight key findings, research trends, and future directions. Methods Data from the Primary Tumor Retrospective (PT-Retro) and Primary Tumor Research Outcome Network (PTRON) registries were analyzed. The nineteen studies included were peer-reviewed manuscripts focused on primary spine tumors, excluding abstracts, book chapters, systematic reviews, and metastatic studies. Results The PT-Retro registry compiled data from 1495 patients across 18 primary tumor histologies, offering insights into recurrence, survival, and treatment paradigms. Key findings emphasize the importance of Enneking-appropriate (EA) resection in improving survival and reducing recurrence in tumors such as chordoma, chondrosarcoma, and osteosarcoma. Genetic markers, including hTERT promoter mutations and rs2305089 SNP, were linked to prognosis in specific histologies. Benign tumors, such as giant cell tumors and aneurysmal bone cysts, demonstrated variable outcomes with different surgical approaches and selective arterial embolization. Conclusions The AOSKFT registries have significantly advanced knowledge in primary spine tumor management, emphasizing preoperative staging, surgical margins, and multidisciplinary approaches. International, multicentric registries are essential for studying rare diseases like primary spine tumors, enabling robust data collection, improved statistical power, and broader applicability of findings across diverse clinical settings. Ongoing prospective data collection through PTRON will further refine evidence-based care for these rare and challenging conditions.

STUDY DESIGN:Systematic review and meta-analysis. OBJECTIVE:To perform a systematic review and meta-analysis of the impact of social support on outcomes among adults undergoing nontraumatic/nononcologic spine surgery. SUMMARY OF BACKGROUND DATA:Spine surgery patients experience perioperative physical discomfort and psychological stress linked to negative outcomes like persistent pain, prolonged hospital stays, and re-admission. While social support is known to improve postoperative outcomes, its role within spine surgery remains unclear. METHODS:A systematic review was conducted in accordance with PRISMA guidelines. MEDLINE (PubMed), EMBASE (Elsevier), and Scopus (Elsevier) were searched from inception through October 2023. Keywords included adult spine surgery, prognosis, postoperative period, outcomes, and social support. The risk of bias was assessed using the Newcastle-Ottawa Scale. Data regarding social support and outcomes were collected. A meta-analysis was conducted to evaluate the association between social support and postoperative outcomes. RESULTS:In summary, 982 full-text articles were screened, and 22 studies (11,702 patients) met the inclusion criteria. Samples ranged from 19-2070 patients (mean±SD: 532±562). The mean age was 55 years, and 52% were female. Half of the studies reported a significant positive association (P<0.05) between social support (eg, marital status, living environment, and support programs) and a favorable postoperative outcome [readmission rates, pain, mobility, length of stay (LOS), discharge disposition, emergency department visits, and ability to work]. In a meta-analysis (n=5 studies), married individuals had nearly twice the odds of a shorter LOS than nonmarried patients (OR=1.96, 95% CI: 1.28-3.00, I2=57%). CONCLUSIONS:Social support is a key predictor of clinical outcomes for spine surgery patients. While the types of social support reported in the literature were highly heterogeneous, patients with social support experienced shorter hospital stays, fewer readmissions, and increased home discharges. Enhancing perioperative resources for patients with limited social support networks may improve outcomes and enhance recovery for spine surgery patients. LEVEL OF EVIDENCE:Level II.

Instrumentation failure (IF) is a major complication after lumbar spondylectomy for spinal tumors, yet risk factors remain poorly defined. The present study aimed to determine the prevalence of IF and identify variables associated with IF and revision surgery using pooled individual patient data. A systematic review and individual patient data analysis were performed per PRISMA guidelines. PubMed, CDSR, and Epistemonikos were searched through January 2025, and additional patient-level data were obtained from prior series. Studies were included if they reported outcomes after lumbar spondylectomy for primary or metastatic tumors. Demographic, tumor, surgical, and (neo)adjuvant therapy variables were extracted. Statistical analyses included chi-square tests, t-tests, and Firth’s penalized logistic regression. Variables with p < 0.1 on univariable analysis and considered clinically relevant were entered into a penalized multivariable model, with a sensitivity analysis incorporating estimated blood loss as a surrogate of operative burden. A total of 169 patients (mean age 40.7 ± 17.6 years) were included after screening. IF occurred in 14

BACKGROUND CONTEXT:Spinal column tumors with Spinal Instability Neoplastic Scores (SINS) suggesting instability often trigger referrals to spine surgeons. Plasma cell lesions and lymphoma are highly radiosensitive histologies, and may reossify after radiation therapy. The SINS score, designed to assess the need for surgical stabilization for spinal neoplasms, may therefore overestimate instability in patients with these radiosensitive histologies. PURPOSE:Herein we seek to determine if the SINS score is significantly correlated with lesion instability and vertebral compression fracture progression in patients with plasma cell neoplasms or lymphoma of the spine. STUDY DESIGN:This was a retrospective single-institution cohort analysis. PATIENT SAMPLE:Patients with spinal plasma cell or lymphoma lesions with identifiable primary lesions were found by querying our institutional electronic medical record from 2010 to 2024. All patients were at least 18 years of age. OUTCOME MEASURES:Demographics, comorbidities, symptoms, radiation data, surgical data, and imaging data were collected. Outcomes included development of spinal instability, new or progressive vertebral compression fracture, and follow-up neurological status. METHODS:Multivariable logistic regressions were used to evaluate categorical outcomes, while Kaplan-Meier analysis was utilized to assess time to mortality. RESULTS:A total of 240 patients were identified with a mean SINS of 9.79. 23 patients had lesions classified as stable (SINS 0-6, 9.8%), 183 had lesions classified as possibly unstable (SINS 7-12, 76.3%), and 34 had lesions classified as unstable (SINS 13-18, 14.2%). 27 patients underwent surgical management (2 SINS stable, 20 possibly unstable, and 5 unstable), with a 90-day reoperation rate of 11.1% and a 90-day readmission rate of 29.6%. At 3-month follow-up, factors associated with development of instability were higher total SINS score (odds ratio (OR) 1.38, p<.001), SINS unstable lesions compared with possibly unstable lesions (OR 2.69, p=.028), younger age (OR 0.98 per year, p<.001), and higher radiation biologically effective dose (OR 1.03, p<.001). Meanwhile, factors associated with new or progressive vertebral compression fracture were higher total SINS score (OR 1.45, p<.001), SINS unstable lesions compared with possibly unstable (OR 3.59, p=.002), possibly unstable lesions compared with stable (OR Stable 0.22, p=.029), and increased age (OR 1.01 per year, p<.001), while larger baseline VB height (OR 0.91, p<.001) and bisphosphonate or RANK-ligand inhibitor use (OR 0.61, p=.009) were protective. SINS was not significantly associated with follow-up neurological status. CONCLUSIONS:SINS is a useful prognostic factor for the development of instability and new or progressive vertebral compression fracture in patients with plasma cell or lymphoma spinal lesions. However, current thresholds used to define the possibly unstable category may not reliably reflect true instability in these radiosensitive lesions. Surgical decision-making paradigms must be carefully assessed in these patients, given the significant rates of morbidity associated with surgical management of these lesions.

Vertebral metastatic disease results from many types of cancer and can have a devastating impact on patient mobility, psychological health, quality of life, and ultimately overall patient survival. However, the development of radiotherapy and surgical techniques has rapidly surged in conjunction with ongoing advances in basic science and translational studies. In this review, we discuss the paradigm shift in our understanding of the epidemiology and treatment algorithms for spinal oncology, ranging from preoperative optimization strategies, radiation and surgical techniques, the utilization of molecular markers and targeted therapeutics in medical oncology, and prognostication tools that underscore a new multidisciplinary approach to spinal oncology care.

BACKGROUND CONTEXT Pedicle screw–rod constructs are widely used for posterior spinal stabilization; however, screw loosening and toggling remain clinically relevant challenges, particularly in patients with poor bone quality. Existing strategies to improve fixation, including cement augmentation, expandable screws, and modified thread geometries, are associated with added risks, increased procedural complexity, and anatomical constraints. A novel pedicle anchor fixation system has been developed to increase cortical bone contact and improve resistance to toggling without the need for augmentation or expansion mechanisms. PURPOSE To evaluate and compare the biomechanical stability, segmental kinematics, and peri-screw bone stress of a novel anatomically optimized paddle pedicle anchor with those of a conventional pedicle screw in single-level posterior lumbar fixation. STUDY DESIGN/SETTING Cadaver-validated finite element modeling study. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Segmental range of motion (ROM) and peri-screw bone stress. METHODS A validated finite element model of the lumbar spine (L1–L5) was used to simulate physiological motion. The model included anatomically accurate representations of vertebral bodies, intervertebral discs, ligamentous structures, and musculature. Posterior instrumentation was applied at L4–L5 using either a standard pedicle screw system or a 3D-printed paddle-shaped anchor system (Pohewi Medical TANTO Anchors), both connected with 5.5-mm titanium rods. A 400-N compressive follower load was applied to simulate physiologic preload, followed by 10-Nm moments to simulate flexion, extension, lateral bending, and axial rotation. Segmental ROM at index and adjacent levels and peri-screw bone stresses were calculated and compared across intact, conventional screw, and anchor models. RESULTS In the intact model, index-level ROM was 5.8° (flexion), 2.8° (extension), 4.0° (left bending), 3.7° (right bending), 2.3° (left rotation), and 2.9° (right rotation). ROM decreased to 0.51°, 0.37°, 0.41°, 0.50°, 0.42°, and 0.48°, respectively, with standard pedicle screws, and further decreased to 0.30°, 0.20°, 0.30°, 0.38°, 0.29°, and 0.33° with the pedicle anchor system. Both constructs demonstrated a slight increase (<10%) in adjacent segment ROM. Peri-screw bone stress was reduced by approximately 20% in the pedicle anchor model compared to the conventional screw model across all loading conditions. CONCLUSIONS The novel pedicle anchor system demonstrated improved biomechanical stability compared with conventional pedicle screws in single-level lumbar fixation. The anchor construct provided greater restriction of segmental motion while maintaining similar adjacent segment kinematics and reducing peri-screw bone stress. These findings suggest potential for reduced risk of screw loosening, particularly in patients with compromised bone quality. Further experimental and clinical studies are warranted to evaluate long-term performance. FDA Device/Drug Status Pohewi Medical TANTO Anchors (approved for this indication).

Background:Cervical degenerative disc disease is a common indication for surgical intervention to stabilize vertebral segments and alleviate symptomatic radiculopathy or myelopathy. While anterior cervical discectomy and fusion (ACDF) has long been a standard procedure for these cases, more recently, cervical disc arthroplasty (CDA) has offered a motion preserving alterative to potentially reduce adjacent segment degeneration (ASD). Although cost-effectiveness data exist for single- and two-level procedures, there remain no direct comparisons for three-level CDA constructs. This study retrospectively evaluates admission costs and 3-month clinical outcomes between three-level CDA and ACDF to evaluate each procedure's relative cost-effectiveness. Methods:In this single-system retrospective study, patients receiving elective three-level CDA (n=10) or ACDF (n=10) for degenerative cervical pathology were compared. Exclusion criteria included acute trauma, infection, or tumors. Data collected included patient demographics, comorbidities, symptoms, radiological findings, procedural details, postoperative complications, and 3-month clinical outcomes. Financial metrics, normalized to institutional cost units, included total admission costs and subcategories [e.g., equipment cost, operating room (OR) cost]. Statistical comparisons employed Kruskal-Wallis and chi-square tests (P<0.05 threshold). Results:Cohorts exhibited comparable baseline characteristics, including age (CDA: 52.3±9.6 years; ACDF: 58.7±7.4 years), comorbidities, symptoms, and diagnoses (P>0.05). Operative times trended longer for CDA (268.6±40.7 min) vs. ACDF (222.8±84.4 min; P=0.08). No intraoperative complications occurred in either cohort, and postoperative complications were not significantly higher for CDA vs. ACDF (30% vs. 10%; P=0.58). There were no significant differences in 3-month symptom resolution and readmission/reoperation rates between procedures (P>0.40). Total admission costs were markedly elevated for CDA (78.04 units) compared to ACDF (46.25 units; +68.75%, P<0.001), driven predominantly by equipment costs (+152.34%, P<0.001), with lesser increases in OR (+32.97%, P=0.006), anesthesia (+56.0%, P=0.008), and radiology costs (+74.56%, P=0.005). Conclusions:Three-level CDA incurs substantially higher admission costs than ACDF without short-term clinical superiority. These findings highlight equipment-driven cost differences amid comparable clinical efficacy, suggesting ACDF may be superior to CDA in three-level cases where motion preservation is not essential and cost is a significant consideration. However, further cost-utility analyses are necessary to evaluate how differences in long-term ASD rates and reoperations may compensate for the higher short-term admission costs of CDA.

Patients with cancer requiring surgery are at increased risk for depressive symptoms. However, prevalence and severity during the perioperative period are poorly characterized. This study systematically reviewed the perioperative prevalence of clinically significant depression and depressive symptom severity in patients with cancer, as measured by self-reported tools. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using PubMed, EMBASE, and Scopus databases (searched to 15 December 2023). Clinical studies of patients with cancer undergoing surgery that measured depressive symptoms using a self-reported instrument were included. Study quality and bias were assessed using the Oxford Centre for Evidence-Based Medicine Levels of Evidence and Joanna Briggs Institute Critical Appraisal Checklist. Data extracted included study characteristics, as well as prevalence and severity of depression pre- and postoperatively. Data from 526 studies involving 103,075 surgical patients were included. The most common cancers were breast (32

Disruptive technologies are reshaping the landscape of spine surgery by enhancing precision, improving patient outcomes, and transforming surgical training and planning. This review explores the integration of augmented reality (AR), virtual reality (VR), patient-specific implants, endoscopic techniques, advanced navigation, and robotics in spine surgery. Preoperative applications include immersive VR-based resident training and AR-assisted surgical planning, which have demonstrated improved accuracy and confidence in trainees. Patient-specific surgeries leverage advanced segmentation and 3D printing to tailor implants and procedures to individual anatomy. Intraoperative technologies such as endoscopic and robot-assisted spine surgery offer minimally invasive alternatives with favorable recovery profiles, while neuronavigation improves workflow and reduces radiation exposure. Despite their potential, these innovations face challenges related to high costs, limited accessibility, and the need for rigorous validation. This narrative review highlights current trends, clinical outcomes, and ethical considerations in the adoption of these technologies, emphasizing the importance of equitable implementation and standardization of outcomes and training across diverse healthcare settings.

Background: Chordoma is a rare bone cancer with limited treatment options. Clinical trials are crucial for developing effective therapies, but their success depends on including diverse patient populations. The objective of this study was to systematically evaluate the reporting of racial, ethnic, and socioeconomic diversity in United States clinical trials exploring treatment for chordoma. Methods: A literature search was conducted through PubMed/Medline, Cochrane, Epistemonikos, and ClinicalTrials.gov databases for published US chordoma trials up until 19 August 2024. The data collected included trial characteristics and racial and ethnic data, as well as socioeconomic indicators when available. Methodological Index for Non-Randomized Studies (MINORS) and Revised Cochrane Risk-of-Bias Tool for Randomized Trials (RoB2) analyses were adopted to assess the methodological quality. The N-1 Chi-squared (χ2) test was implemented to compare the reported racial and ethnic data with the most recent US Census Bureau data. Results: Five trials involving 111 patients (median age: 63 years; 34% female) were included. Four studies (80%) were single-arm non-randomized studies with one study (25%) having a high methodological quality and three (75%) having a moderate quality based on the MINORS analysis. Most patients (91%, n = 82) were White/Caucasian, representing a proportion which was significantly higher than the reported 75% in the US population (p = 0.0005). Black/African American patients (2%, n = 2) were significantly underrepresented compared to the 14% in the US population (p = 0.0015). Regarding ethnicity, Hispanic/Latino patients (7%, n = 6) were significantly underrepresented compared to the 20% in the US population (p = 0.0021). No measures of socioeconomic status were reported. Conclusions: This systematic review highlighted the need for improved racial and ethnic diversity in chordoma trials and the better reporting of socioeconomic data. The underrepresentation of minority groups may obscure potential disparities in disease incidence, treatment access, and clinical outcomes.

STUDY DESIGN:Narrative Literature review. OBJECTIVE:To provide a general overview of important molecular markers and targeted therapies for the most common neoplasms (lung, breast, prostate and melanoma) that metastasize to the spine and offer guidance on how to best incorporate them in the clinical setting. METHODS:A narrative review of the literature was performed using PubMed, Google Scholar, Medline databases, as well as the histology-specific National Comprehensive Cancer Network guidelines to identify relevant articles limited to the English language. Relevant articles were reviewed for commonly described molecular mutations or targeted therapeutics, as well as associated clinical outcomes, and surgery-related risks. RESULTS:Molecular markers and targeted therapies have dramatically improved the survival of cancer patients. The increasing importance of prognostic molecular markers and targeted therapies provides rationale for their incorporation into clinical decision-making for patients diagnosed with metastatic spine disease. In this review, we discuss the molecular markers/mutations and targeted therapies associated with the most common malignancies that metastasize to the spine and provide a framework that the surgeon can utilize when evaluating patients for potential intervention. Finally, we provide case examples that highlight the importance of molecular prognostication and therapies in surgical decision-making. CONCLUSION:An integrated understanding of the implications of surgery, radiation, molecular markers and targeted therapies that guide prognostication and treatment is warranted in order to achieve the most favorable outcomes for patients with metastatic spine disease.

STUDY DESIGN:Delphi consensus. OBJECTIVE:To define an optimal surgical composite outcome measure in patients with metastatic spine disease (OSCO-M) through international consensus among key opinion leaders. MATERIALS AND METHODS:Members of the AO Spine Knowledge Forum Tumor, an international group of dedicated spine oncology surgeons and oncologists, participated in a modified Delphi process between March 2023 and November 2024. The study was conducted in 2 parts. The first part aimed on identifying which outcome variables were deemed important to be included in the composite outcome. The second part focused on the definition of a successful outcome with regards to the agreed variables from Part 1. Each part consisted of a questionnaire and a consensus meeting. Consensus was achieved when a threshold of 70% agreement was reached. RESULTS:A total of 42 dedicated spine oncology surgeons and oncologists from North America, Latin America, Europe, and Asia participated. Over 87% of respondents agreed that composite measures reflect the multidimensional aspect of the surgical process more than an individual outcome variable. Most respondents (93%) agreed/strongly agreed that composite measures should be used to assess the quality of surgical care in spine oncology. Through consensus, the following three outcome variables were selected to define the OSCO-M: the absence of SAVES-V2 (Spinal Adverse Events Severity System, Version 2) grade 3 adverse events or higher within 30 days of surgery, maintaining or improving ECOG (Eastern Cooperative Oncology Group) performance status at 90 days, and being ambulatory (with or without aid) at 90 days. CONCLUSION:This is the first study defining a composite outcome measure in oncologic surgery for spinal metastases derived from an international group of key opinion leaders in spine oncology. The OSCO-M may be useful for future research in spine tumor patients and serve as a benchmark to optimize outcomes.

OBJECTIVE:Large language models (LLMs) have shown promising performance on medical licensing examinations, but their ability to excel in subspecialty domains and their robustness under adversarial conditions remain unclear. Herein, the authors present AtlasGPT, a subspecialty-focused LLM for neurosurgery, and evaluate its performance on a benchmark multiple-choice question bank and under adversarial testing, as well as its ability to generate high-quality explanations. METHODS:AtlasGPT was built by fine-tuning GPT-4 architecture and retrieval-augmented generation from neurosurgical knowledge sources. Its performance was compared with that of GPT-4 and Gemini Advanced on a 149-question neurosurgery examination. Adversarial testing assessed robustness to misinformation. Answer explanations were rated by 15 independent neurosurgeons and compared with the question bank. RESULTS:Across all 149 questions and on text-only questions, AtlasGPT (96%) outperformed Gemini Advanced (93%) and GPT-4 (88%) in accuracy. In adversarial testing, under which AtlasGPT was tasked with identifying medical misinformation, it was fooled 14% of the time, compared with 44% for GPT-4 and 68% for Gemini Advanced. Neurosurgeons rated AtlasGPT's answer explanations as significantly more comprehensive, relevant, and better referenced than the question bank's explanations of the responses (p < 0.001). AtlasGPT did not demonstrate any evidence of hallucination or other content that would be harmful for patient care or the surgeon's clinical decision. CONCLUSIONS:AtlasGPT demonstrates the potential of subspecialty-focused LLMs to outperform general models, exhibit robustness to misinformation, and generate high-quality explanations. Domain-specific LLMs may improve medical knowledge, decision-making, and educational materials in complex fields like neurosurgery.

INTRODUCTION:While glucagon-like peptides 1 receptor agonists (GLP-1RAs) grow in popularity, their potential for presurgical weight optimization in spine surgery remains unclear. We examined the influence of semaglutide prescription on one- to three-level transforaminal lumbar interbody fusion (TLIF) outcomes. METHODS:Retrospective analysis of obese, non-diabetic patients was conducted from 2018 to 2022. A 1:1 exact match paired semaglutide users with non-users based on age, gender, surgical levels, and comorbidities. The primary outcome were the rates of surgical and medical complications at 30 days following TLIF. A sub analysis assessed outcomes after stratifying by prescription duration (greater or less than nine months). Kaplan-Meier survival analyses evaluated the need for additional lumbar fusion. The alpha was set to 0.05, but with the Bonferroni correction the significance threshold was set to 0.0045. RESULTS:471 semaglutide users were matched with 471 non-users with no baseline differences. Semaglutide users had higher rates of pneumonia (2.97 % vs 0.85 %, p < 0.05) compared to nonusers. When stratified by prescription duration, patients with longer semaglutide use had a higher incidence of urinary tract infection (4.03 % vs 1.27 %, p < 0.05) and acute kidney injury (3.18 % vs 0.85 %, p < 0.05). The need for additional lumbar fusion was associated with both semaglutide use (17.0 % vs. 6.4 %, p < 0.0001) and duration (28.3 % vs. 4.8 %, p < 0.0001). CONCLUSIONS:Semaglutide may adversely affect lumbar fusion outcomes and necessitate additional surgery, possibly secondary to its systemic effects on bone metabolism and weight loss patterns. Further research into optimal drug formulation, dosage, and weight loss protocols will be required before mainstream use.

BACKGROUND CONTEXT: Clinical outcomes are directly related to patient selection and treatment indications for improved quality of life. With emphasis on quality and value, it is essential that treatment recommendations are optimized. PURPOSE: The purpose of the North American Spine Society (NASS) Appropriate Use Criteria (AUC) is to determine the appropriate (ie, reasonable) multidisciplinary treatment recommendations for patients with metastatic neoplastic vertebral fractures across a spectrum of more common clinical scenarios. STUDY DESIGN: A Modified Delphi process. PATIENT SAMPLE: Systematic Review. OUTCOME MEASURES: Final rating for cervical fusion recommendation as either "Appropriate," "Uncertain," or "Rarely Appropriate" based on the median final rating among the raters. METHODS: The methodology was based on the AUC development process established by the Research AND Development (RAND) Corporation. The topic of neoplastic vertebral fracture was selected by NASS for its Clinical Practice Guideline development (CPG). In conjunction, the AUC work group determined key modifiers and adopted the standard definitions developed by CPG, with minimal modifications. A literature search and evidence analysis performed by the CPG were reviewed by the AUC work group. A separate multidisciplinary rating group was assembled. Based on the literature, provider experience, and group discussion, each scenario was scored on a 9-point scale on 2 separate occasions, once without discussion and then a second time following discussion based on the initial responses. The median rating for each scenario was then used to determine if indications were rarely appropriate (1-3), uncertain/maybe appropriate (4-6), or appropriate (7-9). Consensus was not mandatory. RESULTS: Medical management was essentially always appropriate. Radiation therapy was appropriate 50% of the time and uncertain otherwise, and directly related to radiosensitivity of the tumor. Ablation was never rated appropriate with agreement, and about 50% of the time was rated as uncertain. For cement augmentation, the scenarios without stenosis or neurological changes, stable fractures with less than 80% height loss and intact posterior wall, and higher VAS pain scores accounted for 88% probability of an appropriate rating. Otherwise, cement augmentation was uncertain 68% of the time. Surgery was rated as appropriate with agreement in 35%, and uncertain or appropriate with disagreement in 59% of scenarios. The most important variables determining final rating for surgery (in order) were stability, spinal stenosis, and prognosis. CONCLUSIONS: Multidisciplinary appropriate treatment criteria were generated based on the RAND methodology. Recommendations were made for medical treatment, ablation, radiation, cement augmentation, and surgery based on 432 practical clinical scenarios. This document provides comprehensive evidence-based recommendations for evaluation and treatment of metastatic neoplastic vertebral fractures. The document in its entirety will be found on the NASS website (https://www.spine.org/Research-Clinical-Care/Quality-Improvement/Appropriate-Use-Crite ria). (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Study Design.Retrospective propensity-score matched, case-control study at 2 academic tertiary care centers. Objective.To assess the effect of preoperative embolization (PE) on (1) intraoperative blood loss, defined as conventional estimates of blood loss (EBL) and hemoglobin mass loss; and (2) secondary outcomes in patients with spinal metastases from hypervascular histologies. Background Context.PE intends to reduce blood loss during surgery for spinal metastases of hypervascular tumors such as renal cell carcinoma. However, studies investigating the effect of PE in hypervascular tumors often consist of small cohorts, do not correct for confounding factors, and have conflicting results. Materials and Methods.After propensity score matching, 46 PE patients were matched to 46 non-PE patients without baseline differences. The constraints of propensity score matching did not allow analysis of patients with tumor volumes >9 cm3. Multiple linear regression models were fitted for EBL and hemoglobin mass loss. Poisson regression models were fitted for both intraoperative and postoperative transfusions. Results.There was no difference in EBL [948 mL (IQR: 500-1750) vs. 1100 mL (IQR: 388-1925), P=0.68] and hemoglobin mass loss [201 g (IQR: 119-307) vs. 232 g (IQR: 173-373), P=0.18] between PE and non-PE patients. Other than higher 1-year survival rates (65% vs. 43%, P=0.05) in PE patients, there were no differences in secondary outcomes. In multiple regression analyses, PE was not associated with decreased intraoperative blood loss, hemoglobin mass loss, or perioperative blood transfusions. Conclusions.Our study demonstrated that, for tumors <9 cm3, PE did not reduce EBL, hemoglobin mass loss, or perioperative blood transfusions in patients undergoing spine surgery for metastases from hypervascular histologies. These findings suggest that urgent spine surgeries indicated for hypervascular histologies should not be delayed based on the availability of PE and accurate detection of preoperative hypervascularity, beyond histology, will likely be an important determination of future PE utilization for spinal metastases. Level of Evidence.Level III-treatment benefits.