Accurate spinal cord segmentation is important for quantitative analysis of spinal cord magnetic resonance imaging, including measurement of cross-sectional area and diffusion-based microstructural characterization. In pathological conditions like cervical myelopathy, the shape deformation induced by cord compression is extreme, rendering automated segmentation particularly challenging. While deep learning-based methods yield good results in healthy or mildly pathological cases, their reliability suffers when anatomical assumptions fail under compression. In this work, we introduce a pathology-aware, boundary-focused preprocessing framework that directly aims to mitigate failure modes imposed by cord compression. Instead of generic preprocessing, each component aims to enhance intensity homogeneity, suppress noise and improve boundary visibility. At the core of this approach is a multi-representation input derived from a single T2*-weighted scan, whereby complementary intensity-, contrast- and edge-enhanced representations are fed to the U-Net model. The proposed framework is evaluated on spinal cord MRI data from three clinical centers (194 cervical myelopathy cases). The results demonstrate that the proposed preprocessing framework improves segmentation accuracy, robustness, and stability, particularly in anatomically challenging regions affected by compression. These findings highlight the importance of pathology-aware preprocessing for reliable spinal cord segmentation in cervical myelopathy.

Radiographic angle measurements are fundamental for diagnosing, classifying and monitoring spinal deformities. Reported variability of 2–7° led to the adoption of empirical margins (often 5°) to define clinically meaningful change. Because vertebral corners represent anatomical regions rather than exact points, geometric and imaging-related factors impose a fundamental limit on precision. This study aimed to quantify how uncertainty in landmark identification and vertebral size influence the precision of radiographic spinal angle measurements, and to provide a mechanistic explanation for commonly applied angular margins. A simplified geometric model of radiographic angle measurement was explored using Monte Carlo simulation. Vertebral endplates were represented as line segments of length L (15–60 mm), spanning cervical to lumbar dimensions. Landmark placement uncertainty was modeled as isotropic variability within a circular region of radius R (0.25–2.5 mm). Measurement uncertainty was quantified using the 95

Retrospective study. This work aims to estimate using machine learning the occurrence of knee flexion in relation to spinopelvic parameters in lumbar degenerative pathologies. Adult spinal deformity (ASD) significantly impairs quality of life, prompting the need for preoperative alignment assessment. Common compensatory mechanisms include thoracic hypokyphosis and pelvic retroversion. With the advent of full-body EOS imaging, spinopelvic measures understanding improved. In fact, there are strong correlations between knee flexion and HRQoL underscore the importance of estimating knee flexion for informing interventions to improve well-being in patients. This retrospective single-center study includes patients with degenerative spinal pathologies necessitating surgical fusion. Parameters were extracted from radiographs using SterEOS® software and included spinopelvic parameters. Knee-related parameters were not used. The database was split into learning (80

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is the most common cause of acquired nontraumatic spinal cord injury worldwide. Surgery is a common treatment for DCM; however, outcomes often vary across patients. PURPOSE: To inform preoperative education and counseling, we performed a responder analysis to identify factors associated with treatment response. STUDY DESIGN/SETTING: An observational cohort study was conducted utilizing prospectively collected data from the Canadian Spine Outcomes Research Network (CSORN) registry collected between 2015-2022. PATIENT SAMPLE: We included all surgically treated DCM patients with complete 12-month follow-up and patient-reported outcomes (PROs) available at 1-year. OUTCOME MEASURES: Treatment response was measured using the minimal clinically important difference (MCID) in PROs including the Neck Disability Index (NDI) and EuroQol-5D (EQ5D) at 12 months postsurgery. METHODS: A Least Absolute Shrinkage and Selection Operator (LASSO) machine learning model was used to identify significant associations between 14 preoperative patient factors and likelihood of treatment response measured by achievement of the MCID in NDI, and EQ-5D. Variable importance was measured using standardized coefficients. To test robustness of findings we trained a separate XGBOOST model, with variable importance measured using SHAP values. RESULTS: Among the 554 DCM patients included, 229 (41.3%) and 330 (59.6%) patients responded to treatment by meeting or surpassing MCID thresholds for NDI and EQ-5D at 1-year, respectively. LASSO regression for likelihood of treatment response measured through NDI found the variable importance rank order to be baseline NDI (OR 1.06 per 1 point increase; 95% CI 1.04 - 1.07), then symptom duration (OR 0.65; 95% CI 0.44-0.97). For EQ-5D, the variable importance rank order was baseline EQ-5D (OR 0.16 per 0.1-point increase; 95% CI 0.03-0.78), living independently (OR 2.17; 95% CI 1.22-3.85), symptom duration (OR 0.62; 95% CI 0.40-0.97), then number of levels affected (OR 0.80 per additional level; 95% CI 0.67-0.96). A separate XGBoost model of treatment response measured through NDI, corroborated findings that patients with higher baseline NDI, and shorter symptom duration were more likely to respond to treatment, and additionally found older patients, and those with kyphosis on baseline upright X-ray were less likely to respond. Similarly, an XGBoost model for treatment response measured through EQ-5D corroborated findings that patients with higher baseline EQ-5D, shorter symptom duration, living independently, with fewer affected levels were more likely to respond to treatment, and additionally found older patients were less likely to respond. CONCLUSIONS: Our findings suggest patients with shorter symptom duration, higher baseline patient NDI, lower EQ-5D, younger age, living independently, without kyphosis on preoperative X-ray, and fewer affected levels are more likely to respond to treatment. Timing of surgery with respect to patient symptoms is underscored as a crucial and modifiable patient factor associated with improved surgical outcomes in DCM. (c) 2024 Published by Elsevier Inc.

BACKGROUND CONTEXT:While abundant literature supports the clinical benefits of surgery for degenerative cervical myelopathy (DCM), limited evidence exists regarding the extent to which patients' preoperative expectations are met postoperatively. PURPOSE:This study primarily aimed to report the fulfillment of preoperative expectations 12 months postsurgery. Secondary objectives included identifying predictors of expectation fulfillment and overall patient satisfaction following surgical intervention for DCM. STUDY DESIGN/SETTING:We conducted a multicenter analysis of spine surgery patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN)-DCM prospective cohort. PATIENT SAMPLE:Patients who underwent surgical treatment for DCM between April 2015 and September 2022 were included. OUTCOME MEASURES:Patients completed a preoperative 11-domain expectation questionnaire, quantifying their expected clinical changes in each domain. At 12 months postoperatively, patients reported the extent to which their preoperative expectations were met in each domain, as well as their overall satisfaction with surgical outcomes. METHODS:Multivariable logistic regression models were employed to identify and validate variables associated with expectation fulfillment and satisfaction. RESULTS:Among the 490 patients included, 49.2% had all their expectations met and 3.7% had none of their expectations met. The expectations that were most frequently met were prevention of neurological decline (87.5%) and maintaining of independence (86.7%). There were 83% of patients who were satisfied at 12 months. Multivariable logistic regression identified preoperative variables (not smoking, not using pain medication presurgery, having lower levels of depressive symptoms (PHQ-8)), surgical variables (anterior and posterior nonfusion approaches), the absence of peri‑operative adverse events and improvement in pain and Health-Related Quality of life scores at 12 months (NRS neck-pain, SF12 PCS and SF-12 MCS scores) as predictors of expectation fulfillment. Improvement in the mJOA score was not a predictor of expectation fulfillment. Having preoperative expectations met was a strong predictor of being satisfied with the surgery (p<.01). CONCLUSIONS:The majority of patients undergoing surgery for degenerative cervical myelopathy (DCM) reported satisfaction with their outcomes, with nearly half experiencing complete fulfillment of their preoperative expectations. Importantly, we identified 9 independent predictors of expectation fulfillment, which in turn emerged as a strong determinant of overall patient satisfaction. These findings highlight the critical role of personalized preoperative counseling in optimizing surgical outcomes. By aligning patients' expectations with realistic goals through individualized care strategies, clinicians may significantly enhance patient satisfaction and the perceived value of surgical intervention in DCM.

Introduction MRI is increasingly recognised as a valuable tool for assessing prognosis and predicting outcomes following traumatic spinal cord injury (SCI). Several potential MRI biomarkers have been identified, but efforts are still needed to improve the accuracy and feasibility of these biomarkers in clinical practice. This study aims to build a national Canadian SCI imaging repository for storing and analysing imaging data for SCI, with the goal of improving SCI MRI biomarkers to predict outcomes and inform clinical management.Method and analysis As a substudy of the Rick Hansen SCI Registry (RHSCIR), this retrospective multisite study includes individuals who sustained a traumatic cervical SCI between 2015 and 2021, were previously enrolled in RHSCIR, and had MRI scans acquired within 72 hours of injury and before any surgical intervention. Individuals with a penetrating trauma and/or with any prior spine surgery are excluded. The study principal investigator and research associates, experienced with data curation and with the standardised format and specifications of the Brain Imaging Data Structure standard, guide the site’s curator on the steps to perform image deidentification and curation to create standardised datasets across all sites. These datasets are transferred to a Digital Research Alliance of Canada (‘the Alliance’) server designated for this project and concatenated to form the national Canadian SCI imaging repository (Neurogitea). We are using a semiautomated processing pipeline to quantify lesion morphology, together with additional imaging measures that are manually extracted from the images (for instance, the relative maximal spinal cord compression and the maximum canal compromise). Through linkage to RHSCIR clinical and epidemiological data already available on eligible participants, regression analysis is planned to predict neurological outcomes at discharge, including the American Spinal Injury Association Impairment Scale grade, upper and lower extremity motor and sensory scores.Ethics and dissemination This protocol has been submitted by the participating sites to obtain ethics and institutional approvals prior to the study initiation at each site. All 12 sites across Canada have now obtained ethics and institutional approvals. Study results will be disseminated at local, national and international conferences and by journal publications.

BACKGROUND CONTEXT Significant variability in the management of Adult Spinal Deformity (ASD) has been observed among spine surgeons worldwide. The variability among Canadian spine surgeons, a country with universal public healthcare, remains unknown. PURPOSE The study aims to evaluate areas of variability in the perioperative optimization and surgical management of ASD among Canadian spine surgeons. STUDY DESIGN/SETTING In this cross-sectional study, 25 Canadian spine surgeons, predominantly orthopedic surgeons (20) and neurosurgeons (5) with varying experience, participated in an online survey focused on Adult Spinal Deformity (ASD). SAMPLE The study involved 25 Canadian spine surgeons with varying level of experience, representing both orthopedic and neurosurgical specialities. OUTCOME Measure The study aimed to evaluate the variability in surgical decision-making and perioperative optimization strategies among Canadian spine surgeons when faced with simulated scenarios of ASD pathologies. METHODS The online survey presented 4 vignettes with simulated scenarios of the most common ASD pathologies, including High Grade Spondylolisthesis (HGS), Neglected Adolescent Idiopathic Scoliosis (NAIS), Degenerative Scoliosis (DS), and Flat Back Syndrome (FBS). Questions in the vignettes explored ASD surgical decision-making, while additional questions focused on perioperative optimization. Descriptive statistics were used to analyze multiple-choice responses, and open-text responses were categorized into themes. RESULTS Variability was observed in the duration conservative treatment across the 4 ASD cases. Surgeons exhibited variability in the use of preoperative osteoporosis treatment. There was varied use of a dedicated anesthesiology team. Surgical goals varied in HGS and NAIS. The primary surgical method was variable in DS and HGS, the type of osteotomy varied in DS and FBS, and level of fixation varied in HGS and NAIS. Consensus was observed in the use of intraoperative monitoring across of all 4 ASD pathologies, the implementation of a team-based approach, and the selection of the primary surgical goal in DS and FBS. CONCLUSION Our cross-sectional study revealed variability among Canadian spine surgeons in the management of ASD, potentially influenced by the uncertain ASD progression, the need for evidence-based nonsurgical guidelines, and insufficient evidence on optimal surgical approaches. These findings will help guide future research to ultimately reduce variability and improve ASD patient management and outcomes.

STUDY DESIGN:Multicenter observational cohort study. OBJECTIVE:To quantify upper extremity sensory recovery following surgical decompression for degenerative cervical myelopathy (DCM), identify predictors of sensory improvement, and evaluate its association with postoperative health-related quality of life (HRQoL). SUMMARY OF BACKGROUND DATA:Sensory dysfunction is a hallmark feature of DCM. However, prior studies have focused on overall neurological improvement rather than domain-specific outcomes, leaving the trajectory and impact of sensory recovery poorly characterized. METHODS:We used prospectively collected data from the Canadian Spine Outcomes and Research Network (CSORN). Sensory function was assessed using the modified Japanese Orthopedic Association (mJOA) sensory subdomain at baseline, 3 months, and 12 months postoperatively. Changes in sensory score were categorized as improved, stable, or worsened. HRQoL was evaluated using the SF-12 Physical and Mental Component Scores (PCS and MCS). Multivariable linear regression was performed to assess the independent association between sensory improvement and 12-month PCS and MCS. Multivariable logistic regression identified predictors of sensory improvement. RESULTS:Among 682 patients with baseline sensory deficits, 490 had 12-month follow-up data. Of these, 245 (50%) demonstrated sensory improvement, 226 (46%) remained stable, and 19 (4%) worsened ( P <0.001). Patients who improved experienced significant increases in PCS (from 31.4 to 40.5, P <0.001) and MCS (from 42.7 to 48.0, P <0.001). In adjusted models, sensory improvement was independently associated with higher PCS (+1.98, P =0.016) and MCS (+2.34, P =0.007), while worse baseline upper and lower extremity motor scores predicted greater odds of recovery (ORs 0.78 and 0.75, respectively). CONCLUSIONS:Sensory improvement after surgical decompression for DCM is common and independently associated with meaningful HRQoL gains. Patients with more severe baseline motor deficits are more likely to improve. These findings highlight the prognostic value of baseline function and support incorporating sensory outcomes into preoperative counseling.

OBJECTIVE:Journal editorial and society executive boards have widespread impacts, however, the associated leadership diversity remains underexplored. Our study evaluated such diversity across four surgical specialties before the influences of COVID-19. METHODS:This retrospective, cross-sectional study obtained perceived gender and race of identified leaders from publicly available websites. Leadership of the top three journals and journal-affiliated societies based on the 2021 Journal Citation Reports journal impact factor was evaluated for subspecialties within neurosurgery, orthopaedic, general, and plastic surgery. RESULTS:Leadership diversity within 58 journals and 55 societies were reviewed. Orthopedics had a significantly lower proportion of females (p ​< ​0.05) and intersectional minorities (p ​< ​0.05). Higher journal impact factor and a greater proportion of intersectional minorities were significantly related (p ​= ​0.0009). CONCLUSION:We assessed leadership diversity amongst both journal editorial and society executive boards and identified differences with respect to proportions of females, minorities and intersectional minorities across specialties.

OBJECTIVE:The objective of this study was to determine minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) including the 12-Item Short-Form Health Survey (SF-12) Physical Component Summary (PCS), SF-12 Mental Component Summary (MCS), and Neck Disability Index (NDI) in patients with degenerative cervical myelopathy (DCM) undergoing surgery, and to assess whether MCID values vary by baseline disease severity. METHODS:The authors retrospectively analyzed prospectively collected data from the Canadian Spine Outcomes and Research Network for DCM patients treated surgically between 2015 and 2023. Inclusion required a baseline modified Japanese Orthopaedic Association (mJOA) score and 3- or 12-month follow-up PROs with domain-specific anchor responses. Patients were stratified by baseline mJOA score into mild (score ≥ 15), moderate (score 12-14), and severe (score < 12) groups. MCID values for the SF-12 PCS, SF-12 MCS, and NDI were calculated using anchor-based receiver operating characteristic curve analysis, with responder status defined by anchor questions. Discriminative performance was assessed via area under the curve, and 95% confidence intervals were estimated by bootstrapping. RESULTS:Among 290 patients meeting inclusion criteria, 77 (26.6%) were classified as having mild myelopathy, 120 (41.4%) moderate, and 93 (32.1%) severe. In the overall cohort, the MCID values were estimated as 8.9 (95% CI 7.5-10.9) for SF-12 PCS, 4.3 (95% CI 2.3-5.6) for SF-12 MCS, and 13.5 (95% CI 11.5-15.5) for NDI. Stratified SF-12 PCS MCID values increased from an estimated 4.8 (95% CI 1.1-7.7) in mild cases to 8.4 (95% CI 6.1-11.3) in moderate and 14.8 (95% CI 10.4-17.7) in severe cases. The NDI MCID values similarly rose from 10.5 (95% CI 6.5-12.5) to 15.0 (95% CI 10.5-19.0) to 17.5 (95% CI 14.5-21.0) across the mild, moderate, and severe groups, respectively. In contrast, the SF-12 MCS MCID values were 4.5 (95% CI 1.4-7.4) for mild, 3.8 (95% CI 0.4-5.8) for moderate, and 4.4 (95% CI 1.9-8.3) for severe patients, which did not differ significantly across severities. CONCLUSIONS:MCID values for PROs in DCM patients undergoing surgery increase with baseline severity. These findings indicate the importance of stratifying patients by disease severity to enhance the clinical relevance of MCID values, facilitate personalized treatment goals, and improve outcome assessments.

BACKGROUND AND OBJECTIVES:Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. The natural history of mild DCM is not fully understood, and both operative and nonoperative strategies have been proposed as treatment modalities. The aim of this study was to analyze the outcome of patients with mild DCM treated nonoperatively and identify risk factors for neurological deterioration and conversion to surgery. METHODS:All patients with mild DCM (modified Japanese Orthopaedic Association [mJOA] score 15-17), enrolled between 2015 and 2023, who were initially treated nonoperatively, as part of an ongoing prospective, multicenter observational cohort study were included. Neurological function (mJOA), patient-reported outcomes (neck disability index, EuroQol-5D, short form-12, numeric rating scale [NRS]), and radiographic findings at enrollment and 1 year were assessed. Progression of disease was defined as neurological deterioration by ≥2 mJOA. Conversion to surgery was a secondary end point. RESULTS:One hundred forty patients with mild DCM were initially treated nonoperatively. The mean mJOA score was 16.8 ± 0.8, with no clinically significant change after 1 year (16.5 ± 1.3; P = .031). Improved EuroQol-5D, relief in the NRS arm, and neck pain below the minimal clinically important difference level were noted after 1 year. A drop of ≥2 mJOA points occurred in 13.3% (n = 14). Seventeen patients (12.1%) crossed over to surgical treatment at an average time of 3.4 years. Patients who crossed over had lower baseline mJOA scores (16.2 ± 1.0 vs 16.7 ± 0.9; P = .03), but otherwise comparable patient-reported outcomes at baseline ( P > .05). Delayed surgery improved NRS neck pain (5.0 ± 3.1 vs 1.9 ± 1.4; P = .02). CONCLUSION:Neurological deterioration or the need for surgery is relatively uncommon in patients with conservatively treated mild DCM. A deterioration rate of 13.3% at 1 year and a conversion rate of 12.1% over 3.4 years with no clear risk factors were noted. Crossover patients presented with worse mJOA. No other clinically significant parameter was found to be a risk factor for neurological deterioration nor a driver for crossover.

BACKGROUND:Patients with stiff spines are at increased risk of instability after THA because of pelvic stiffness. Comprehensive study of patients with a stiff spine without hip arthritis could provide insight into native compensatory mechanisms and provide guidance on the mechanics to account for after arthroplasty. QUESTIONS/PURPOSES:The primary aim of this study was to characterize static and dynamic compensatory mechanics that occur in the presence of either a stiff hip or stiff spine. The secondary study aims were to assess which spinopelvic imaging modalities would best uncouple compensation mechanisms and to test the effect of length of spinal fusion (that is, number of fused segments) on the existing compensatory mechanics. METHODS:This was a prospective, case-control study performed at two academic tertiary referral centers. The cohort studied included three groups: (1) the control group of asymptomatic volunteers without signs of hip osteoarthritis or history of spinal surgery (n = 52); (2) the hip group of patients with osteoarthritis treated with THA between 2018 and 2019 (n = 512), excluding those with age < 18 years (n = 2), BMI > 40 kg/m 2 (n = 9), different diagnosis than osteoarthritis (n = 117), history of spinal or lower limb disease or surgery (n = 206), neurologic comorbidities (n = 17), absence of study consent (n = 20), or without spinopelvic radiographs (n = 17), in which the included patients (n = 124) were matched for age, sex, and BMI to the control group, resulting in the final hip group of 52 patients; and (3) the spine group were patients seen in clinic between 2023 and 2024 (n = 121), 1 year after spinal fusion, excluding those with BMI > 40 kg/m 2 (n = 10), hip osteoarthritis or surgery (n = 16), neuromuscular disease (n = 1), spinal fusion not including lumbar spine (n = 1), or without spinopelvic radiographs (n = 41), leaving 52 patients. The whole cohort comprised 60% (93 of 156) females, and the mean ± SD age was 64 ± 11 years. All underwent standing, relaxed-, and deep-seated radiographs to determine static characteristics: lumbar lordosis, pelvic tilt, pelvic-femoral angle, and pelvic incidence. Dynamic characteristics included difference in pelvic tilt, lumbar lordosis, and pelvic-femoral angles between standing and relaxed- or deep-seated positions, thereby determining which imaging modality best uncoupled compensatory mechanisms. Correlation between the number of fused segments and spinopelvic parameters was assessed using Spearman correlation coefficient. RESULTS:When standing, the spine group had a higher mean ± SD pelvic-femoral angle than the control (197° ± 7° versus 186° ± 10°, mean difference -11° [95% confidence interval (CI) -14° to -7°]; p < 0.001) and hip group (197° ± 7° versus 183° ± 11°, mean difference -14° [95% CI -18° to -10°]; p < 0.001) and a higher pelvic tilt compared with the control (20° ± 9° versus 15° ± 8°, mean difference -5° [95% CI -8° to -2°]; p = 0.003) and hip group (20° ± 9° versus 15° ± 7°, mean difference -5° [95% CI -9° to -2°]; p = 0.004). Dynamically, the spine group exhibited the least lumbar flexion (ΔLL) in both relaxed- (12° ± 11° versus 22° ± 12° versus 16° ± 12°; p = 0.002) and deep-seated transitions (25° ± 14° versus 43° ± 13° versus 43° ± 13°; p < 0.001). Between standing and deep-seated, change in pelvic tilt was greater in the spine group compared with the hip (20° ± 16° versus -6° ± 16°, mean difference -28° [95% CI -33° to -22°]; p < 0.001) and control group (20° ± 16° versus 4° ± 17°, mean difference -19° [95% CI -26° to -13°]; p < 0.001). Deep-seated, the spine group flexed the hip more than the hip group (109° ± 15° versus 70° ± 21°, mean difference -40° [95% CI -47° to -34°]; p < 0.001) and control group (109° ± 15° versus 85° ± 18°, mean difference -23° [95% CI -30° to -16°]; p < 0.001). Standing to deep-seated assessments better uncoupled compensatory mechanisms, as these detected differences between control and spine group (for instance, ∆LL standing/deep-seated 43° ± 13° versus 25° ± 14° [mean difference 19° (95% CI 14° to 25°); p < 0.001] versus ∆LL standing/relaxed-seated 16° ± 12° versus 12° ± 11° [mean difference 4° (95% CI 0° to 9°); p = 0.15]). The number of segments fused was associated with deep-seated lumbar lordosis (ρ = 0.55; p < 0.001) and pelvic tilt (ρ = -0.31; p = 0.02). CONCLUSION:In this study, patients with a stiff spine have hyperextended hips when standing and hyperflexed hips in a deep-seated position and exhibit a fivefold greater change in pelvic tilt between these positions compared with controls. The greater pelvic tilt change may cause an acetabular cup to be brought in a functionally suboptimal orientation, leading to impingement or dislocation. Deep-seated radiographs can uncouple compensatory mechanisms and are recommended to better identify patients with spinal stiffness. LEVEL OF EVIDENCE:Level II, diagnostic study.

STUDY DESIGN:Prospective cohort study. OBJECTIVE:The aims of this study were primarily to evaluate the association between patient-reported symptom duration and postoperative outcomes in patients with degenerative cervical myelopathy (DCM). Secondly, to identify factors associated with the extended duration of symptoms before surgical consultation for DCM. SUMMARY OF BACKGROUND DATA:Surgery is the gold standard treatment for progressive or at least moderate DCM; however, the impact of extended symptom duration on patient outcomes remains unknown. MATERIALS AND METHODS:This study analyzed patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) from 2015 to 2023. Patients with mild to severe DCM with 1-year follow-up were included. During initial assessment, surgeons recorded symptom duration as reported by patients categorically with six choices, which were then dichotomized as a binary variable using a 1-year threshold. Differences between groups were analyzed using unadjusted bivariate analysis, and the associations between symptom duration on achievement of minimally clinically important differences (MCID) of PROMs were assessed using multivariable logistic regression analysis. RESULTS:A total of 483 patients (227 with symptoms less than 1 year and 256 with symptoms 1 year or greater) were included. At baseline, BMI (mean=28.2 vs . 29.5, P <0.008), number of comorbidities (2.8 vs . 3.1, P <0.029), and proportion of tobacco users (51% vs . 82%, P <0.027) were significantly higher among those with symptoms 1 year or greater, who also had higher baseline mJOA scores (12.5 vs . 13.2, P <0.002) and worse neck pain (5.63 vs . 4.92, P <0.004). Symptom duration of less than 1 year was associated with higher odds of achieving MCID for the outcomes Neck Disability Index (OR=1.64, 95% CI=1.05-2.55, P <0.030), SF-12 PCS (OR=1.98, 95% CI=1.22-3.19, P <0.005), and EQ-5D (OR=2.08, 1.30-3.33, P <0.002) at 12 months after surgery. The odds of reaching the MCID for the mJOA did not significantly differ by symptom duration (OR=1.41, 95% CI=0.88-2.24, P <0.153). CONCLUSION:Patients with symptom durations1 year or greater at the time of consulting a spine surgeon experienced inferior postoperative outcomes for disability and health-related quality of life compared with patients with symptom durations of less than 1 year, despite similar neurological outcomes. Smoking was among the factors associated with a prolonged duration of symptoms. These results suggest that efforts to prioritize early diagnosis by primary care physicians and timely referral for surgery are warranted. LEVEL OF EVIDENCE:Level 3.

BACKGROUND CONTEXT:Proper implant selection and placement in oblique lumbar intervertebral fusion (OLIF) are essential to achieve the best possible results for the patient. Key factors such as interbody cage length, height, angle, and material must all be carefully considered to achieve the intended results and minimize complications. Significant challenges remain in selecting the appropriate cage parameters to control spinal alignment while minimizing subsidence risk. Ongoing debates include how long a cage should be to optimize load distribution, as well as how variations in cage angle and placement influence the outcomes. PURPOSE:This study aims to biomechanically model and investigate how variations in interbody cage dimensions, positioning, and material properties influence indirect decompression, realignment, and resulting stresses involved in cage subsidence. STUDY DESIGN:Computational biomechanical study of interbody cage and OLIF influence on correction outcomes. METHODS:A pathological finite element model of the L4-L5 segment presenting a grade I spondylolisthesis was used to simulate 172 different OLIF configurations, evaluating cage position (anterior, central, posterior), angle (6° or 12°), material (PEEK or titanium), length (40 to 60 mm), and height (10 to 14 mm). Bilateral pedicle screw fixation was also tested. The simulated outcomes included disc height, foraminal and spinal canal dimensions, segmental lordosis, vertebral slip, endplate stresses, and displacements under various loading conditions. Statistical comparisons were tested to analyze the influence of model, implant, and surgical parameters on correction outcomes. RESULTS:Longer (left-to-right dimension) cages (60 mm), which overhang on both sides of the vertebrae and sit on the apophyseal ring, significantly reduced vertebral endplate displacements and stresses by 33% compared to shorter cages (40 mm) (p < 0.05). Posterior cage positioning improved the decompression but raised stresses by 45% and reduced segmental lordosis by 28%. Lowering cage height from 14 to 10 mm and increasing the angle from 6° to 12° reduced endplate stresses by 53% and 33%, respectively. BPS fixation decreased stresses by 36% on average. The trends observed concurred with recently published OLIF clinical studies. CONCLUSIONS:This study highlights the biomechanical influence of implant characteristics and positioning on OLIF results and subsidence risks. Competing factors unveil an optimization problem that can be effectively addressed with the help of accurate, robust, and reproducible numerical simulations and regression models. This study further confirms that the developed tools not only accurately simulate the surgical approach and corroborate clinical findings but also offer a relevant framework for in-depth analysis. CLINICAL SIGNIFICANCE:Leveraging numerical methods, this study provides biomechanical insights into how variations in cage parameters during OLIF procedures influence outcomes. The findings aim to help clinicians refine strategies to attain desired outcomes (decompression and alignment) while understanding the consequences on the risk of subsidence. By aligning with clinical trends, our results offer valuable explanations and support for biomechanical-based surgical decision-making.

BACKGROUND CONTEXT Recent evidence suggests that adding fusion to decompression is not required for many patients with degenerative lumbar spondylolisthesis (DLS); however, decompression and fusion remains the most common procedure for these patients. While the surgical spine community strives to determine the right procedure for the right patient, the significant clinical and radiographic heterogeneity in DLS patients has not been objectively characterized. PURPOSE 1) to apply machine learning techniques to identify distinct clinical-radiographic DLS phenotypes; 2) to determine the impact of these phenotypes on outcomes following decompression with (DF) and without (DA) fusion. STUDY DESIGN/SETTING Multicentre (eight sites), prospective, longitudinal, observational cohort study. PATIENT SAMPLE Canadian Spine Outcomes and Research Network (CSORN)-DLS patients (n=486), without scoliosis, undergoing 1-2 level procedures at the surgeons’ discretion. OUTCOME MEASURES 1- and 2-year Oswestry Disability Index (ODI) measures. METHODS Consensus cluster analysis was used based on comprehensive demographic, clinical, and radiological characteristics of patients enrolled from 2015 to 2022. We utilized eight clinical and eleven radiographic features and evaluated the optimal number of clusters. Euclidean distance metric was used to determine the cluster number and structure, with up to ten clusters considered and 100 sampling iterations. Key characteristics of each cluster were identified, and post-surgical outcomes were compared with pairwise statistical tests using the ODI. RESULTS The cohort mean age was 66.4 ± 9.2 years, and 63% of patients were female. DA was performed on 29.1% and 71% received DF. Analysis identified four distinct clusters: I) Female patients with moderate disability (ODI=39.9±12.6), minimal dynamic translation (2±2.4 mm), high pelvic incidence (PI=62±11.50), and balanced in the sagittal plane (SVA=22±30 mm); II) Female patients with high number of comorbidities, severe disability (ODI=51±12), higher grade listhesis and dynamic translation (3.18±3 mm), high PI (PI=63.3±10.70) and grossly imbalanced/decompensated in the sagittal plane (SVA=76±42.8 mm); III) Male patients with moderate disability (ODI=38.3±16.4) , minimal dynamic translation (1.7±1.7 mm), average PI (PI=53.5±9.20), but imbalanced in the sagittal plane (SVA=56.5±42.7 mm); and IV) Older patients with high number of comorbidities, severe disability (ODI=50.6±14.1), minimal dynamic translation (1.4±1.8 mm), average PI (PI=51.7±100), and balanced in the sagittal plane (SVA=37.7±34.4 mm). All clusters demonstrated clinically significant improvement at 1- and 2-year ODI for both groups. Fusion was the dominant surgical procedure of choice in all clusters, highest in Cluster II (84%). DA provided sustained improvement at 2 years equal to that of fusion in Clusters 1, 3, 4, but regressed in Cluster 2. CONCLUSIONS Using comprehensive clinical and radiographic data from a pragmatic, national cohort (without scoliosis, undergoing 1-2 level surgery), machine learning techniques identified four unbiased, distinct phenotypes that represent the heterogenous clinical and radiographic spectrum of DLS patients. These phenotypes allow for better clinical and research stratification. The clinically significant and sex specific sagittal plane imbalance in approximately one-third of our DLS cohort warrants further study. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT:Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. While surgical intervention is widely recognized as the primary treatment to halt disease progression and improve neurological function, its effectiveness in alleviating neck pain remains poorly understood. PURPOSE:The aims of this study were to identify DCM patients that presented with severe neck pain and to compare their baseline characteristics and surgical outcomes to those who presented with less severe neck pain. STUDY DESIGN/SETTING:This is a prospective, multicenter observational cohort study of the Canadian Spine Outcomes and Research Network (CSORN). SAMPLE:Patients surgically treated for DCM between 2015 and 2022 were enrolled. OUTCOME MEASURE:Baseline demographics, clinical/surgical details, PROs and mJOA were assessed. METHODS:Baseline demographics, clinical/ surgical details, preoperative PROs and mJOA were compared between the patients with severe patient-rated neck pain (NP, defined as NRS-NP ≥ 8), and those with less severe NP. Between group improvements at 12 months were assessed using ANCOVA to adjust for any baseline significant differences between groups. RESULTS:We included data from 725 DCM patients, 31.7 % (n=230) of whom presented with severe NP. Patients with severe NP were significantly more likely to be younger, smokers, unemployed, working rather than retired, unmarried, using pain medication, have a history of depression, have more comorbidities, and be physically less active (all p<.05). Baseline PROs (NRS AP and NP, NDI, SF-12 MCS and PCS and EQ5D) were significantly worse (p<.01), but mJOA scores were similar to those without severe NP. Among patients with severe NP, mean NRS-NP improved from 8.6 (SD 0.8) to 3.9 (SD 2.9, p<.01) at 12 months after surgery. Patients with severe NP were more likely to achieve MCID for neck pain in comparison to those without severe NP (74% vs 33%, p<.01), but mean NRS-NP remained worse in this subgroup (3.9 vs 2.6, p<.01) at 1 year after surgery. When adjusted for baseline characteristics, there were no differences between the 2 groups for the following PROs at 12 months postoperatively: NRS arm pain, NDI, SF-12 PCS, EQ5D. SF-12 MCS remained significantly worse among patients who presented with severe NP (p<.05). There was no significant difference in mJOA scores (report data) at 1 year after surgery. CONCLUSION:Severe neck pain affects about a third of the DCM population. Most patients who presented with severe neck pain experienced substantial improvement of their neck pain after surgery. Except for mental health scores which remained worse, patients with severe neck pain experienced similar improvements in other outcome measures such as neurological function and health-related quality of life when compared to those with less severe neck pain. These findings suggest that surgical treatment not only addresses the structural causes of DCM but also provides meaningful improvements across multiple domains, underscoring its value in managing both the physical and psychosocial burdens of the disease.

The objective of this investigation is to evaluate whether enhancements in health-related quality of life (HRQOL), consequent to efficacious cervical spine surgery in individuals diagnosed with degenerative cervical myelopathy (DCM), lead to improvements in mental health metrics. The primary outcome assessed was the change between the preoperative and postoperative SF12 Mental Component Score (MCS) alongside the modified Japanese Orthopedic Association (mJOA) scores. Secondary outcomes include SF-12 Physical Component Score (PCS), EQ-5D, Neck Disability Index (NDI), Patient Health Questionaire-9 (PHQ9), and neck pain scale.The Canadian Spine Outcome Research Network registry was queried for all patients who received surgery for DCM with ≥12-month follow-up. Exclusion criteria were trauma, tumor, infection, and previous spine surgery. Patients were categorized into six distinct cohorts based on their SF-12 MCS (pre-operative presence or absence of depression) and mJOA (mild, moderate, or severe DCM). SF12 Mental Component Scores (MCS) were compared between those with and without significant improvement (reaching Minimally Clinically Important Differences (MCID)) for mJOA and between disease severity groups. Multivariate analysis examined factors predictive of MCS improvement. 22 hospitals contributed 500 eligible patients. There was a greater significant improvement in MCS and NDI 12-months post-op across all cohorts in the depressed cohort more than in their respective non-depressed cohorts. Patients exceeding MCID in mJOA had the greatest improvements in MCS regardless of disease severity. Major depression prevalence decreased by 43% following the degenerative cervical myelopathy surgery. Of all the factors studied, sole the presence of depression pre-operatively is predictive of improved MCS post-operatively with an odd ration of 4. Our data suggests that successful surgery for DCM is associated with improvement of MCS and decrease in prevalence of major depression, and this decrease in was more pronounced in patients with pre-operative depression regardless the severity of DCM.

BACKGROUND:Anterior lumbar interbody fusion (ALIF) is an alternative for treating spine pathologies. Bone substitutes are increasingly used to enhance fusion and minimize iliac graft harvest complications. Despite numerous options, no gold standard exists. After we started using anorganic bone matrix/15-amino acid peptide fragment (ABM/P-15), we observed unexpected abnormal findings on postoperative CT scan. Our study aimed to investigate this matter: is ABM/P-15 associated with a higher rate of these findings than other substitutes? Do they impact fusion or clinical outcomes? HYPOTHESIS:We hypothesized that the use of ABM/P-15 was associated with more unexpected findings, potentially impacting fusion or clinical outcomes. PATIENTS AND METHODS:This retrospective study included patients undergoing ALIF between 2020 and 2022, divided into two groups: one having received ABM/P-15 and the other different bone substitutes (InductOS, TBF, MagnetOs, ß gel). Unexpected findings (migration or calcification) and fusion rates were evaluated on postoperative (3- and 12-month) CT scan. Clinical outcomes (Oswestry Disability Index (ODI) and pain) were also measured. RESULTS:Among 152 patients (76 per group), unexpected findings were more prevalent with ABM/P-15 [40 patients (53%) vs 1 (1%); p < 0.001]. Regardless, both groups were similar in fusion rates at 1 year [72 patients (95%) vs 68 (89%); p = 0.367] and clinical outcomes (ODI decrease: 17 vs 19 points, p = 0.491). CONCLUSION:ABM/P-15 showed a higher incidence of unexpected findings (calcification or product migration) than other bone substitutes, with no impact in fusion success or clinical outcomes. LEVEL OF EVIDENCE:III.

BACKGROUND CONTEXT Degenerative cervical myelopathy (DCM) is considered the most common cause of spinal cord dysfunction and it is expected to become more prevalent as populations age. As a progressive disease, patients affected have limited independence and poorer quality of life. Early diagnosis and treatment are paramount in achieving a good outcome, as early treatment can halt progression and improve functional recovery. PURPOSE In our study we analyze patient reported outcome measures (PROMs) for patients treated surgically for DCM in a 5 year follow up study. STUDY DESIGN/SETTING Retrospective study. PATIENT SAMPLE A total of 171 patients from CSORN database met the inclusion criteria. OUTCOME MEASURES Numeric arm and neck pain score, neck disability index (NDI) Score, modified Japanese Orthopaedic association (mJOA) score and short form-12 (SF-12). METHODS Using CSORN database (multicenter retrospective database). Patients who underwent surgery for cervical myelopathy and completed 5 years follow up were included and exclusion criteria included patients with pathological fractures, trauma or infection. Patient reported outcome measures (PROMs) used were numeric arm and neck pain, NDI Score, mJOA score and SF-12. Variables included age, demographics, comorbidities, duration of symptoms, numeric arm and neck pain, NDI Score, mJOA score and SF-12. Mean (SD) or median (IQR) were reported. Paired T-test was used to compare means of outcome between follow-ups and baseline. Wilcoxon signed-rank test was applied to compare median of outcome between follow-ups and baseline. For all statistical tests, two-tailed test was used to determine significance at 5% level. All data manipulation and statistical analysis were performed using Statistical Analysis System, version 9.4 (SAS Institute Inc., Cary, North Carolina, USA). RESULTS A total of 171 patients met the inclusion criteria. Eighty patients (47%) had a duration of symptoms over 2 years. There was a statistically significant (p <0.0001) improvement in the median score for arm and neck pain that was apparent at 3 months and sustained in all follow up (F/U) periods. NDI score showed improvement at the 3 months F/U with p =0.0017, at 1 year F/U NDI score showed further improvement (p <0.0001) compared to baseline. This improvement continued throughout the F/U. mJOA scores also showed improvement, the mean score at baseline was 13.2, at 5 years F/U the score showed a mean of 15. improvement in mJOA score at each F/U was statistically significant compared to baseline (p <0.0001). SF-12 mental and physical components (MCS and PCS respectively) showed improvement in our data with PCS showed peak improvement at 1 year F/U (mean 38.9) compared to baseline (mean 32.4) and 3 months F/U (mean 35.2). The mean MCS improvement was apparent at the 3 months F/U with a mean of 48.3 (vs 44.1 at baseline), and the same score was noted at 12 months F/U. At 2 and 5 years F/U the mean scores showed a mild decline (PCS at 2 years =38 and 5 years =37.9 and mean MCS at 2 years =48.1 and at 5 years =47.2). Within the CSORN database, 996 patients were included in the timeframe, 186 patients reached the 5 years F/U and 3.8% of them were lost to follow up. Out of our cohort, 83% of patients were discharged home with no professional supervision needed. CONCLUSIONS In our study, patients undergoing surgery for cervical myelopathy showed improved clinical results after surgery. This improvement was sustained at 5 years follow up. No significant deterioration in PROMs was noted. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.