Clinical applications of AI-prediction tools in spine surgery: a narrative review.

Spine surgery has grown into a wide, complex field encompassing trauma surgery to deformity to tumours. Artificial intelligence (AI) based technology has been particularly useful in improving imaging-reporting and detection of predictive patterns. The purpose of this narrative review is to present practical approaches towards implementing upcoming AI spine research for clinicians to help improve practices, clinical throughput, and surgical decision-making.

Spine Surgery in a Geriatric Population. Is it Really Different?

OBJECTIVES: Spinal degenerative disorders are a major cause of morbidity in the elderly resulting in high dependency. Most of them have a trend to be managed conservatively considering age, comorbidities, and apprehensions of surgical complications. Surgical intervention at early stage with appropriate indications can have better outcomes rather than conservative management in fit patients. The objective of the study is to evaluate the functional outcome in geriatric patients > 60 years who have undergone various spinal procedures for degenerative spine. METHODS: The study is retrospective, which includes all cases of spinal degenerative disease operated between 2014 and 2016. They were divided into geriatric (>60 years) and non-geriatric cohorts. These include all patients undergoing spinal decompression and/or instrumentation for degenerative disorders of the spine. Patients were interviewed for their functional outcomes in the follow-up period. RESULTS: A total of 184 spine cases were operated upon by a single surgeon, out of which a total of 139 cases were operated for the spinal degenerative condition. Forty-eight patients underwent lumbar spinal fusion procedures, 67 underwent non-instrumented lumbar decompression, and 24 patients underwent cervical procedures. These were further divided into 65 geriatric cases and 74 non-geriatric cases. The outcome was assessed with improvement and functional outcomes for spinal disability. Statistical analysis was performed using SPSS 20. CONCLUSION: It is concluded that surgical intervention for spinal problems in geriatric patients is not different from the general population. The outcome is also satisfactory provided, the choice of surgical procedure as per its indication is appropriate. The usual preoperative evaluation for the geriatric age group is very important. The performance status before surgery and the comorbidities have a direct bearing on the outcome in these patients.

Cutting Edge Developments in Spine Surgery at the University of Missouri.

The treatment of spinal pathologies has evolved significantly from the times of Hippocrates and Galen to the current era. This evolution has led to the development of cutting-edge technologies to improve surgical techniques and patient outcomes. The University of Missouri Health System is a high-volume, tertiary care academic medical center that serves a large catchment area in central Missouri and beyond. The Department of Neurosurgery has sought to integrate the best available technologies to serve their spine patients. These technological advancements include intra-operative image guidance, robotic spine surgery, minimally invasive techniques, motion preservation surgery, and interdisciplinary care of metastatic disease to the spine. These advances have resulted in safer surgeries with enhanced outcomes at the University of Missouri. This integration of innovation demonstrates our tireless commitment to ensuring excellence in the comprehensive care of a diverse range of patients with complex spinal pathologies.

The Epidemiology of Spinal Neurosurgery in Nigeria: A Systematic Review and Patient-Level Analysis.

OBJECTIVE: Spinal pathologies are prevalent in Nigeria, though epidemiological data remains sparse. This systematic review used pooled patient-level data from across the country to generate a standardized epidemiological reference. METHODS: Four research databases and gray literature sources were searched. Risk of bias assessment was conducted using Risk of Bias in Non-Randomised Studies - of Interventions and Cochrane's risk of bias tool. We descriptively analyzed all article metrics and statistically analyzed relevant data variables via paired t-test and χ2 independence tests (α = 0.05). RESULTS: One hundred twenty-seven articles, comprising a patient cohort of 8425 patients, were analyzed. Most were retrospective cohort studies (46.5%) and case reports/series (31.5%), with an overall moderate-high risk of bias. Most studies were published in the last 20 years. Most patients were male (∼2.5 males per female), with an average age of 43.2 years (±16.4). Clinical diagnoses spanned the breadth of spinal neurosurgery. Approximately 45.0% of patients had complete spinal impairment. Pain (41.7%) was the most reported presenting feature. X-ray (45.1%) was the most common investigation used. Intervertebral disc herniation (18.9%) was the most prevalent imaging finding on MRI. Most patients were managed nonoperatively (57.8%), with a favorable outcome in 27.4% of patients. Posttreatment complications included pressure sores, infection, and motor deficits. CONCLUSIONS: This systematic review and pooled analysis provide an epidemiological overview of spinal neurosurgery in Nigeria over the last 60 years and serves as a useful reference to direct future global research in this arena.

Paraspinous Muscle Flaps in Complex Pediatric Spine Surgeries: A 12-Year Single Institution Experience.

PURPOSE: The benefits of paraspinous flaps in adult complex spine surgery patients are established in the literature; however, their use in pediatric patients has not been well described. This study compares clinical outcomes with and without paraspinous muscle flap closure in pediatric patients who have undergone spine surgery. METHODS: We conducted a retrospective review of all pediatric spine surgeries at the University of California, San Francisco from 2011 to 2022. Patients were divided into 2 cohorts based on whether the plastic surgery service closed or did not close the wound with paraspinous muscle flaps. We matched patients by age, American Society of Anesthesiology classification, prior spinal surgical history, and diagnosis. Surgical outcomes were compared between the 2 cohorts. RESULTS: We identified 226 pediatric patients who underwent at least one spinal surgery, 14 of whom received paraspinous flap closure by plastic surgery. They were matched in a 1:4 ratio with controls (n = 56) that did not have plastic surgery closure. The most common indication for plastic surgery involvement was perceived complexity of disease by the spine surgeon with concern for inadequate healthy tissue coverage (78.6%), followed by infection (21.4%). Postoperative complications were similar between the two groups. The plastic surgery cohort had a higher rate of patients who were underweight (57.1% vs 14.3%, P < 0.01) and had positive preoperative wound cultures (28.6% vs 8.9%, P = 0.05), as well as a higher rate of postoperative antibiotic usage (78.6 vs 17.9%, P < 0.01). There was no difference in recorded postoperative outcomes. CONCLUSIONS: Spine surgeons requested paraspinous flap closure for patients with more complex disease, preoperative infections, history of chemotherapy, or if they were underweight. Patients with paraspinous flap coverage did not have increased postoperative complications despite their elevated risk profile. Our findings suggest that paraspinous muscle flaps should be considered in high-risk pediatric patients who undergo spine surgery.

Comparison of outcomes after anterior cervical discectomy and fusion with and without a cervical collar: a systematic review and meta-analysis.

PURPOSE: The clinical outcomes of patients who received a cervical collar after anterior cervical decompression and fusion were evaluated by comparison with those of patients who did not receive a cervical collar. METHODS: All of the comparative studies published in the PubMed, Cochrane Library, Medline, Web of Science, and EMBASE databases as of 1 October 2023 were included. All outcomes were analysed using Review Manager 5.4. RESULTS: Four studies with a total of 406 patients were included, and three of the studies were randomized controlled trials. Meta-analysis of the short-form 36 results revealed that wearing a cervical collar after anterior cervical decompression and fusion was more beneficial (P < 0.05). However, it is important to note that when considering the Neck Disability Index at the final follow-up visit, not wearing a cervical collar was found to be more advantageous. There were no statistically significant differences in postoperative cervical range of motion, fusion rate, or neck disability index at 6 weeks postoperatively (all P > 0.05) between the cervical collar group and the no cervical collar group. CONCLUSIONS: This systematic review and meta-analysis revealed no significant differences in the 6-week postoperative cervical range of motion, fusion rate, or neck disability index between the cervical collar group and the no cervical collar group. However, compared to patients who did not wear a cervical collar, patients who did wear a cervical collar had better scores on the short form 36. Interestingly, at the final follow-up visit, the neck disability index scores were better in the no cervical collar group than in the cervical collar group. PROSPERO registration number: CRD42023466583.

Clinical Outcomes and Complication Profile of Spine Surgery in Septuagenarians and Octogenarians: Case Series.

OBJECTIVE: The aging global population presents an increasing challenge for spine surgeons. Advancements in spine surgery, including minimally invasive techniques, have broadened treatment options, potentially benefiting older patients. This study aims to explore the clinical outcomes of spine surgery in septuagenarians and octogenarians. METHODS: This retrospective analysis, conducted at a US tertiary center, included patients aged 70 and older who underwent elective spine surgery for degenerative conditions. Data included the Charlson Comorbidity Index (CCI), ASA classification, surgical procedures, intraoperative and postoperative complications, and reoperation rates. The objective of this study was to describe the outcomes of our cohort of older patients and discern whether differences existed between septuagenarians and octogenarians. RESULTS: Among the 120 patients meeting the inclusion criteria, there were no significant differences in preoperative factors between the age groups (P > 0.05). Notably, the septuagenarian group had a higher average number of fused levels (2.36 vs. 0.38, P = 0.001), while the octogenarian group underwent a higher proportion of minimally invasive procedures (P = 0.012), resulting in lower overall bleeding in the oldest group(P < 0.001). Mobility outcomes were more favorable in septuagenarians, whereas octogenarians tended to maintain or experience a decline in mobility(P = 0.012). A total of 6 (5%) intraoperative complications and 12 (10%) postoperative complications were documented, with no statistically significant differences observed between the groups. CONCLUSIONS: This case series demonstrates that septuagenarians and octogenarians can achieve favorable clinical outcomes with elective spine surgery. Spine surgeons should be well-versed in the clinical and surgical care of older adults, providing optimal management that considers their increased comorbidity burden and heightened fragility.

The Effect of Diabetes on Complications after Spinal Fusion: A Systematic Review and Meta-Analysis.

OBJECTIVE: Spinal fusion procedures are used to treat a wide variety of spinal pathologies. Diabetes mellitus (DM) has been shown to be a significant risk factor for several complications following these procedures in previous studies. To the authors' knowledge, this is the first systematic review and meta-analysis elucidating the relationship between DM and complications occurring after spinal fusion procedures. METHODS: Systematic literature searches of PubMed and EMBASE were performed from their inception to October 1, 2022, to identify studies that directly compared postfusion complications in patients with and without DM. Studies met the prespecified inclusion criteria if they reported the following data for patients with and without DM: (1) demographics; (2) postspinal fusion complication rates; and (3) postoperative clinical outcomes. The included studies were then pooled and analyzed. RESULTS: Twenty-eight studies, with a cumulative total of 18,853 patients (2695 diabetic patients), were identified that met the inclusion criteria. Analysis showed that diabetic patients had significantly higher rates of total number of postoperative complications (odds ratio [OR] = 1.33; 95% confidence interval [CI] = 1.12-1.58; P = 0.001), postoperative pulmonary complications (OR=2.01; 95%CI=1.31-3.08; P = 0.001), postoperative renal complications (OR=2.20; 95%CI=1.27-3.80; P = 0.005), surgical site infection (OR=2.65; 95%CI=2.19-3.20; P < 0.001), and prolonged hospital stay (OR=1.67; 95%CI=1.47-1.90; P < 0.001). CONCLUSIONS: Patients with DM had a significantly higher risk of developing complications after spinal fusion, particularly pulmonary and renal complications, in addition to surgical site infections and had a longer length of stay. These findings are important for informed discussions of surgical risks with patients and families before surgery.

Butterfly Vertebra: A Retrospective Study of 30 Patients.

BACKGROUND: Butterfly vertebra (BV) is a rare congenital spinal anomaly for which there is a paucity of large-scale retrospective studies and established guidelines for treatment. The objective of this study was to elucidate the clinical characteristics, imaging findings, and therapeutic approaches for BV. METHODS: We conducted a retrospective analysis of 30 patients diagnosed with BV at our hospital from 2009 to 2023, examining clinical data, imaging findings, and clinical interventions. RESULTS: The analysis comprised a cohort of 30 patients, consisting of 15 males and 15 females, with a mean age of 27.63 ± 19.84 years. Imaging studies indicated that the majority of vertebral bodies affected by BV were single-segmented (63.3%, 19/30) and less commonly multi-segmented (36.7%, 11/30). These findings frequently coexisted with other medical conditions, most notably spinal scoliosis (76.7%, 23/30). Furthermore, the study identified a range of spinal abnormalities among patients, including hemivertebral deformity (30.0%, 9/30), spinal cleft (10.0%, 3/30), lumbar disc protrusion or herniation (10.0%, 3/30), vertebral slippage (10.0%, 3/30), thoracic kyphosis deformity (6.67%, 2/30), vertebral fusion deformity (6.67%, 2/30), compressive fractures (3.3%, 1/30), and vertebral developmental anomalies (3.3%, 1/30). Clinical intervention resulted in symptom relief for 23 nonsurgical patients through lifestyle modifications, analgesic use, and physical therapy. Seven surgical patients underwent appropriate surgical procedures, leading to satisfaction and adherence to regular postoperative follow-up appointments. CONCLUSIONS: BV is a rare vertebral anomaly that can be easily misdiagnosed due to its similarity to other diseases. Consequently, it is imperative to enhance vigilance in the differential diagnosis process in order to promptly recognize BV. Furthermore, in cases where patients present with additional associated radiographic findings, a thorough evaluation is typically warranted and timely measures should be taken for treatment.

Hydroxyapatite-Coated Screws Versus Titanium Triangular Dowels for Sacroiliac Joint Fusion: Results From a Nonrandomized Prospective Outcome Study.

OBJECTIVE: This is a single-surgeon series that prospectively evaluates the results of sacroiliac joint (SIJ) fusion for patients with SIJ dysfunction using hydroxyapatite-coated screws (HACSs) compared with titanium triangular dowels (TTDs). METHODS: A total of 113 patients underwent SIJ fusion surgery between 2013 and 2018 at the University Hospital Llandough to treat symptomatic SIJ dysfunction not responding to nonoperative measures. Of the 113 patients, 40 were treated with HACSs and 73 with TTDs. Patient-reported outcomes measures (PROMs) were collected preoperatively and at 12 months postoperatively, including the 36-item short-form health survey, Oswestry disability index, EuroQol-5D-5L, and Majeed pelvic score. Patients with ongoing symptoms were followed up beyond the study period. RESULTS: Of the 113 patients, 33 completed follow-up in the HACS group compared with 61 in the TTD group. Both groups had comparable preoperative PROMs; however, the postoperative PROMs were significantly better in the TTD group. Additionally, 21 patients (63%) in the HACS group had radiological evidence of screw lysis compared with 5 patients (9%) in the TTD group. A subgroup analysis revealed less significant improvement in PROMs for patients with screw lysis compared with those without. Four patients were offered further revision surgery. CONCLUSIONS: Minimally invasive SIJ fusion has been shown to have good clinical outcomes for select patients. However, our experience shows that HACSs are associated with a high rate of screw lysis and poorer patient outcomes compared with TTDs. Therefore, we recommend the use of TTDs instead of HACSs for SIJ fusion surgery.

Will ChatGPT be Able to Replace a Spine Surgeon in the Clinical Setting?

OBJECTIVE: This study evaluates ChatGPT's performance in diagnosing and managing spinal pathologies. METHODS: Patients underwent evaluation by two spine surgeons (and the case was discussed and a consensus was reached) and ChatGPT. Patient data, including demographics, symptoms, and available imaging reports, were collected using a standardized form. This information was then processed by ChatGPT for diagnosis and management recommendations. The study assessed ChatGPT's diagnostic and management accuracy through descriptive statistics, comparing its performance to that of experienced spine specialists. RESULTS: A total of 97 patients with various spinal pathologies participated in the study, with a gender distribution of 40 males and 57 females. ChatGPT achieved a 70% diagnostic accuracy rate and provided suitable management recommendations for 95% of patients. However, it struggled with certain pathologies, misdiagnosing 100% of vertebral trauma and facet joint syndrome, 40% of spondylolisthesis, stenosis, and scoliosis, and 22% of disc-related pathologies. Furthermore, ChatGPT's management recommendations were poor in 53% of cases, often failing to suggest the most appropriate treatment options and occasionally providing incomplete advice. CONCLUSIONS: While helpful in the medical field, ChatGPT falls short in providing reliable management recommendations, with a 30% misdiagnosis rate and 53% mismanagement rate in our study. Its limitations, including reliance on outdated data and the inability to interactively gather patient information, must be acknowledged. Surgeons should use ChatGPT cautiously as a supplementary tool rather than a substitute for their clinical expertise, as the complexities of healthcare demand human judgment and interaction.

[Pediatric neurosurgical treatment of aneurysmal bone cyst at the level of thoracic spine]. / Aneurysmás csontcysta gyermek-idegsebészeti megoldása a háti gerinc magasságában.

Aneurysmal bone cysts are benign but locally aggressive bone tumours, most often affecting children and young adults. In this case report, we present the clinical  picture of a 15-year-old boy with progressive, chronic back pain. An MRI of thoracic spine  confirmed a T2 cystic spinal tumour. After considering potential options surgical removal was our choice and gross total removal was achieved with T1-3 short-segment fixation. Aneurysmal bone cysts are often rapidly expanding lesions with vascular  transformation. In order to avoid irreversible damage, in addition to early diagnosis, it is necessary to carefully consider the therapeutic options, perform surgical removal and stabilization as necessary. In case of the presented patient, extensive surgical removal and short-segmentation were performed. At 18 months of follow-up, he had no complaints and was asymptomatic. Follow-up imaging studies showed no residual or recurrent tumour to date.

A Proposed Treatment Algorithm for Low Back Pain Secondary to Bertolotti's Syndrome.

BACKGROUND: Chronic low back pain is widely prevalent, and there are a range of conditions that may result in the low back pain. In general, treatment of low back pain starts with conservative management such as medications, physical therapy, and home exercise regimens. If conservative measures fail, a range of interventional techniques can be employed to manage back pain. An uncommonly recognized cause of back pain is Bertolotti's syndrome which is a result of back pain due to lumbosacral transitional vertebrae (LSTV). LSTV is a congenital abnormality either characterized by the lumbarization of the sacrum where the first sacral bone fails to fuse with the rest of the sacrum or the sacralization of the lumbar spine where the L5 vertebra fuses with the sacrum creating a longer sacrum. In many cases, the condition can be recognized by imaging techniques such as an x-ray, computed tomography, or magnetic resonance imaging. OBJECTIVES: To propose a treatment algorithm for patients with low back pain secondary to Bertolotti's syndrome. STUDY DESIGN: Case study and treatment algorithm proposal. METHODS: A treatment algorithm for patients with low back pain secondary to Bertolotti's Syndrome which involves starting with local anesthetic and steroid injection of the pseudo-articulation, followed by radiofrequency ablation of the pseudo-articulation, and then complete endoscopic resection of the pseudo joint. RESULTS: The proposed stepwise treatment guideline has the ability to diagnose Bertolotti's syndrome as the cause of low back pain and provide symptomatic relief. LIMITATIONS: Several limitations exist for the study including the fact that the algorithmic approach may not fit every patient. Additionally, there would be benefit in future research studies comparing each step of the algorithm with conservative measures to compare efficacy and long-term outcomes of the procedures. CONCLUSIONS: Our stepwise approach to diagnosing and managing the pain resulting from Bertolotti's syndrome is an effective method of treatment for the condition.

Minimally invasive sacroiliac joint fusion using triangular titanium implants versus nonsurgical management for sacroiliac joint dysfunction: a systematic review and meta-analysis.

BACKGROUND: Minimally invasive sacroiliac joint (MISIJ) fusion is a surgical option to relieve SIJ pain. The aim of this systematic review and meta-analysis was to compare MISIJ fusion with triangular titanium implants (TTI) to nonoperative management of SIJ dysfunction. METHODS: We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. We included prospective clinical trials that compared MISIJ fusion to nonoperative management in individuals with chronic low back pain attributed to SIJ dysfunction. We evaluated pain on visual analogue scale, Oswestry Disability Index (ODI) score, health-related quality of life (HRQoL) using the 36-Item Short Form Health Survey (SF-36) physical component (PCS) and mental component summary (MCS) scores, patient satisfaction, and adverse events. RESULTS: A total of 8 articles representing 3 trials that enrolled 423 participants were deemed eligible. There was a significant reduction in pain score with MISIJ fusion compared with nonoperative management (standardized mean difference [SMD] -1.71, 95% confidence interval [CI] -2.03 to -1.39). Similarly, ODI scores (SMD -1.03, 95% CI -1.24 to -0.81), SF-36 PCS scores (SMD 1.01, 95% CI 0.83 to 1.19), SF-36 MCS scores (SMD 0.72, 95% CI 0.54 to 0.9), and patient satisfaction (odds ratio 6.87, 95% CI 3.73 to 12.64) were significantly improved with MISIJ fusion. No significant difference was found between the 2 groups with respect to adverse events (SMD -0.03, 95% CI -0.28 to 0.23). CONCLUSION: Our analysis showed that MISIJ fusion with TTI shows a clinically important and statistically significant improvement in pain, disability score, HRQoL, and patient satisfaction with a similar adverse event profile to nonoperative management in patients with chronic low back pain attributed to SIJ dysfunction.

The current status and development trend of hydrogel application in spinal surgery.

Spinal diseases often result in compromised mobility and diminished quality of life due to the intricate anatomy surrounding the nervous system. Medication and surgical interventions remain the primary treatment methods for spinal conditions. However, currently available medications have limited efficacy in treating spinal surgical diseases and cannot achieve a complete cure. Furthermore, surgical intervention frequently results in inevitable alterations and impairments to the initial anatomical integrity of the spinal structure, accompanied by the consequential loss of certain physiological functionalities. Changes in spine surgery treatment concepts and modalities in the last decade have led to a deepening of minimally invasive treatment, with treatment strategies focusing more on repairing and reconstructing the patient's spine and preserving physiological functions. Therefore, developing novel and more efficient treatment strategies to reduce spinal lesions and iatrogenic injuries is essential. In recent years, significant advancements in biomedical research have led to the discovery that hydrogels possess excellent biocompatibility, biodegradability, and adjustable mechanical properties. The application of hydrogel-based biotechnology in spinal surgery has demonstrated remarkable therapeutic potential. This review presents the therapeutic strategies for spinal diseases based on hydrogel tissue engineering technology.

Advanced practice physiotherapy surgical triage and management of adults with spinal disorders referred to specialized spine medical care: a retrospective observational study.

INTRODUCTION: In this novel advanced practice physiotherapy (APP) model of care, advanced practice physiotherapists (APPTs) assess, triage, and manage adults with spinal disorders to alleviate the growing demands in specialized spine medical care. OBJECTIVES: To describe this APP model of care, to assess change in disability 3 months after rehabilitation care and to assess surgical triage and diagnostic concordance between APPTs and spine surgeons. METHODS: In this retrospective observational study, consecutive patients who completed the 3-month follow-up data were analyzed. Sociodemographic, clinical characteristics, and self-reported disabilities including the Oswestry Disability Index (ODI) and Neck Disability Index (NDI) at baseline and 3 months were extracted. Paired t-tests were used to assess changes in disability. Surgical triage and diagnostic concordance between APPTs and surgeons were measured with raw agreement, Cohen's Kappa, and PABAK. RESULTS: In this model, trained APPTs triaged surgical candidates and provided rehabilitation care including education and exercises to patients with spinal disorders. The APPTs referred only 18/46 participants to spine surgeons. Surgical triage and diagnostic concordance were high with raw agreement of 94% and 89%. At the 3-month follow-up, significant improvements in disability were observed among nonsurgical candidates with back (mean difference (MD): -13.0/100 [95%CI: -19.8 to -6.3], n = 23) or neck disorders (MD: -16.0/100 [95%CI: -29.6 to -2.4], n = 5), but not among surgical candidates referred by APPTs to spine surgeons. CONCLUSION: In this limited sample, adults with spinal disorders that were initially referred to a spine surgeon by family physicians were effectively assessed, triaged, and managed by an APPT.

Predictors of clinical and structural outcomes after surgery for spinal nerve sheath tumor resection: a retrospective analysis.

OBJECTIVE: Resection of spinal nerve sheath tumors (SNSTs) typically necessitates laminectomy, often with facetectomy, for adequate exposure of tumor. While removal of bone affords a greater operative window and extent of resection, it places the patient at greater risk for spinal instability. Although studies have identified risk factors for fusion at the time of tumor resection, there has yet to be a study assessing long-term stability following SNST resection. In this study, the authors sought to identify preoperative and operative risk factors that predispose to long-term spinal instability and investigate clinical variables associated with greater risk for subsequent fusion in the time following initial SNST resection. METHODS: An institutional registry of spinal surgeries was queried at a single institution over a 20-year period. Demographic, clinical, and operative variables were recorded retrospectively and investigated for predictive value of several postoperative sequelae. RESULTS: A total of 122 SNST cases among 112 patients were included. At a mean follow-up time of 27.7 months, patients with a history of neurofibromatosis type 2 (NF2) (p = 0.014) and those who had undergone a laminectomy of ≥ 4 levels at the time of initial SNST resection (p = 0.028) were more likely to present with some degree of structural abnormality or neurological deficit following their initial surgery. The presence of facetectomy, degree of laminectomy, and level of spinal surgery were not found to be predictors of future instability. Ultimately, there was no significant predictor for true spinal instability following index surgery without fusion. A secondary analysis showed that an entirely extradural location (p = 0.044) and facetectomy at index surgery (p = 0.012) were predictive of fusion being performed at the time of tumor resection. Four of the 112 patients required fusion after their index SNST resection, 3 of whom underwent fusion for instability at the level of the index surgery. No variables were identified as predictive for future instrumentation. CONCLUSIONS: Ultimately, the authors conclude that resection of SNSTs does not always necessitate fusion, and good outcomes can be obtained with motion-preserving techniques and minimizing facetectomy when possible. Patients with a history of NF2 and those with SNSTs that required ≥ 4-level laminectomy were more likely to exhibit some degree of structural abnormality and/or neurological deficit localized to the index level defined as either new or worsening spinal instability and/or new or worsening neurological deficit at last follow-up; however, no variable was found to be predictive of true spinal instability. Furthermore, a complete facetectomy at initial SNST resection and entirely extradural tumor location were noted to be associated with fusion at index surgery. Lastly, the authors were unable to identify a clinical predictor for future instrumentation.