Proteomic Portraits Reveal Evolutionarily Conserved and Divergent Responses to Spinal Cord Injury.

Despite the emergence of promising therapeutic approaches in preclinical studies, the failure of large-scale clinical trials leaves clinicians without effective treatments for acute spinal cord injury (SCI). These trials are hindered by their reliance on detailed neurological examinations to establish outcomes, which inflate the time and resources required for completion. Moreover, therapeutic development takes place in animal models whose relevance to human injury remains unclear. Here, we address these challenges through targeted proteomic analyses of cerebrospinal fluid and serum samples from 111 patients with acute SCI and, in parallel, a large animal (porcine) model of SCI. We develop protein biomarkers of injury severity and recovery, including a prognostic model of neurological improvement at 6 months with an area under the receiver operating characteristic curve of 0.91, and validate these in an independent cohort. Through cross-species proteomic analyses, we dissect evolutionarily conserved and divergent aspects of the SCI response and establish the cerebrospinal fluid abundance of glial fibrillary acidic protein as a biochemical outcome measure in both humans and pigs. Our work opens up new avenues to catalyze translation by facilitating the evaluation of novel SCI therapies, while also providing a resource from which to direct future preclinical efforts.

Factors contributing to a longer length of stay in adults admitted to a quaternary spinal care center.

BACKGROUND: Longer hospital length of stay (LOS) has been associated with worse outcomes and increased resource utilization. However, diagnostic and patient-level factors associated with LOS have not been well studied on a large scale. The goal was to identify patient, surgical and organizational factors associated with longer patient LOS for adult patients at a high-volume quaternary spinal care center. METHODS: We performed a retrospective analysis of 13,493 admissions from January 2006 to December 2019. Factors analyzed included age, sex, admission status (emergent vs scheduled), ASIA grade, operative vs non-operative management, mean blood loss, operative time, and adverse events. Specific adverse events included surgical site infection (SSI), other infection (systemic or UTI), neuropathic pain, delirium, dural tear, pneumonia, and dysphagia. Diagnostic categories included trauma, oncology, deformity, degenerative, and "other". A multivariable linear regression model was fit to log-transformed LOS to determine independent factors associated with patient LOS, with effects expressed as multipliers on mean LOS. RESULTS: Mean LOS for the population (SD) was 15.8 (34.0) days. Factors significantly (p < 0.05) associated with longer LOS were advanced patient age [multiplier on mean LOS 1.011/year (95% CI: 1.007-1.015)], emergency admission [multiplier on mean LOS 1.615 (95% CI: 1.337-1.951)], ASIA grade [multiplier on mean LOS 1.125/grade (95% CI: 1.051-1.205)], operative management [multiplier on mean LOS 1.211 (95% CI: 1.006-1.459)], and the occurrence of one or more AEs [multiplier on mean LOS 2.613 (95% CI: 2.188-3.121)]. Significant AEs included postoperative SSI [multiplier on mean LOS 1.749 (95% CI: 1.250-2.449)], other infections (systemic infections and UTI combined) [multiplier on mean LOS 1.650 (95% CI: 1.359-2.004)], delirium [multiplier on mean LOS 1.404 (95% CI: 1.103-1.787)], and pneumonia [multiplier on mean LOS 1.883 (95% CI: 1.447-2.451)]. Among the diagnostic categories explored, degenerative patients experienced significantly shorter LOS [multiplier on mean LOS 0.672 (95%CI: 0.535-0.844), p < 0.001] compared to non-degenerative categories. CONCLUSION: This large-scale study taking into account diagnostic categories identified several factors associated with patient LOS. Future interventions should target modifiable factors to minimize LOS and guide hospital resource allocation thereby improving patient outcomes and quality of care and decreasing healthcare-associated costs.

Malignant transformation of adult-onset pilocytic astrocytoma to diffuse leptomeningeal glioneuronal tumor within the thoracic spine: a case report and review of the literature.

We describe a 31-year-old male who presented with progressive myelopathy from a thoracic pilocytic astrocytoma (PA). Following multiple recurrences and resections, 10 years after his index surgery, pathology revealed diffuse leptomeningeal glioneuronal tumor (DLGNT) with high-grade features. We discuss his clinical course, management, histopathological findings, and present a comprehensive review of spinal PA undergoing malignant transformation in adults and adult-onset spinal DLGNT. To our knowledge, we present the first reported case of adult-onset spinal PA malignant transformation to DLGNT. Our case adds to the paucity of clinical data characterizing such transformations and highlights the importance of developing novel management paradigms.

Degenerative spinal conditions requiring emergency surgery: an evolving crisis in a publicly funded health care system.

BACKGROUND: Surgery for degenerative spine pathologies is typically performed on a scheduled basis; however, worsening symptoms may warrant emergency surgery. An increasing number of patients requiring emergency surgery has been observed (22.6% in 2006 to 34.8% in 2019). We sought to compare the outcomes of patients who received scheduled surgery and those who required emergency surgery. METHODS: All patients treated between Jan. 1, 2006, and Dec. 31, 2019, were included. Retrospective comparisons were made between patients who were scheduled (elective) for surgery and those requiring emergency surgery, patients who were scheduled for surgery and those who decompensated while on the surgical waitlist and patients who presented as de novo emergencies and those who decompensated while on the surgical waitlist. RESULTS: Among the 6217 patients with degenerative pathologies, 4654 (74.9%) patients were scheduled (elective) for surgery and 1563 (25.1%) were patients requiring emergency surgery. Compared with patients who were scheduled, patients requiring emergency surgery had a longer length of stay (LOS) in hospital (5.1 d, interquartile range [IQR] 2.7-11.2 v. 3.6 d, IQR 1.3-6.4, p < 0.001) and lower rate of home discharge (78.6% v. 94.2%, p < 0.001). Patients requiring emergency surgery were 1.34 times more likely to have any adverse events (95% confidence interval [CI] 1.06-1.68, p = 0.01). When compared with patients who were scheduled for surgery, those who decompensated while on the surgical waitlist had longer LOS (7.0 d, IQR 3.3-15.0 v. 3.6 d, IQR 1.3-6.4, p < 0.001), less home discharge (77.6% v. 94.2%, p < 0.001) and were 2.5 times more likely to have any adverse events (95% CI 1.5-4.1, p < 0.001). Patients who decompensated had a 2.1 times higher risk of having any adverse events than patients who presented as de novo emergencies (95% CI 1.2-3.6, p < 0.001). CONCLUSION: We observed worse perioperative outcomes for patients requiring emergency surgery for degenerative spinal conditions than for patients who were scheduled for surgery. Patients who decompensated while on the surgical waitlist had the worst outcomes.

Effectiveness of prophylactic intranasal photodynamic disinfection therapy and chlorhexidine gluconate body wipes for surgical site infection prophylaxis in adult spine surgery.

BACKGROUND: Current measures to prevent spinal surgical site infection (SSI) lack compliance and lead to antimicrobial resistance. We aimed to examine the effectiveness of bundled preoperative intranasal photodynamic disinfection therapy (nPDT) and chlorhexidine gluconate (CHG) body wipes in the prophylaxis of spine SSIs in adults, as well as determine our institutional savings attributable to the use of this strategy and identify adverse events reported with nPDT-CHG. METHODS: We performed a 14-year prospective observational interrupted time-series study in adult (age > 18 yr) patients undergoing emergent or elective spine surgery with 3 time-specific cohorts: before rollout of our institution's nPDT-CHG program (2006-2010), during rollout (2011-2014) and after rollout (2015-2019). We used unadjusted bivariate analysis to test for temporal changes across patient and surgical variables, and segmented regression to estimate the effect of nPDT-CHG on the annual SSI incidence rates per period. We used 2 models to estimate the cost of nPDT-CHG to prevent 1 additional SSI per year and the annual cumulative cost savings through SSI prevention. RESULTS: Over the study period, 13 493 patients (mean 964 per year) underwent elective or emergent spine surgery. From 2006 to 2019, the mean age, mean Charlson Comorbidity Index (CCI) score and mean Spine Surgical Invasiveness Index (SSII) score increased from 48.4 to 58.1 years, from 1.7 to 2.6, and from 15.4 to 20.5, respectively (p < 0.001). Unadjusted analysis confirmed a significant decrease in the annual number (74.6 to 26.8) and incidence (7.98% to 2.67%) of SSIs with nPDT-CHG (p < 0.001). After adjustment for mean age, mean CCI score and mean SSII score, segmented regression showed an absolute reduction in the annual SSI incidence rate of 3.36% per year (p < 0.001). The estimated annual cost to prevent 1 additional SSI per year was about $1350-$1650, and the estimated annual cumulative cost savings were $2 484 856-$2 495 016. No adverse events were reported with nPDT-CHG. CONCLUSION: Preoperative nPDT-CHG administration is an effective prophylactic strategy for spinal SSIs, with significant cost savings. Given its rapid action, minimal risk of antimicrobial resistance, broad-spectrum activity and high compliance rate, preoperative nPDT-CHG decolonization should be the standard of care for all patients undergoing emergent or elective spine surgery.

Dysfunctional paraspinal muscles in adult spinal deformity patients lead to increased spinal loading.

PURPOSE: Decreased spinal extensor muscle strength in adult spinal deformity (ASD) patients is well-known but poorly understood; thus, this study aimed to investigate the biomechanical and histopathological properties of paraspinal muscles from ASD patients and predict the effect of altered biomechanical properties on spine loading. METHODS: 68 muscle biopsies were collected from nine ASD patients at L4-L5 (bilateral multifidus and longissimus sampled). The biopsies were tested for muscle fiber and fiber bundle biomechanical properties and histopathology. The small sample size (due to COVID-19) precluded formal statistical analysis, but the properties were compared to literature data. Changes in spinal loading due to the measured properties were predicted by a lumbar spine musculoskeletal model. RESULTS: Single fiber passive elastic moduli were similar to literature values, but in contrast, the fiber bundle moduli exhibited a wide range beyond literature values, with 22% of 171 fiber bundles exhibiting very high elastic moduli, up to 20 times greater. Active contractile specific force was consistently less than literature, with notably 24% of samples exhibiting no contractile ability. Histological analysis of 28 biopsies revealed frequent fibro-fatty replacement with a range of muscle fiber abnormalities. Biomechanical modelling predicted that high muscle stiffness could increase the compressive loads in the spine by over 500%, particularly in flexed postures. DISCUSSION: The histopathological observations suggest diverse mechanisms of potential functional impairment. The large variations observed in muscle biomechanical properties can have a dramatic influence on spinal forces. These early findings highlight the potential key role of the paraspinal muscle in ASD.

All over the MAP: describing pressure variability in acute spinal cord injury.

STUDY DESIGN: Observational study. OBJECTIVES: To examine the feasibility of meeting the current clinical guidelines for the hemodynamic management of acute spinal cord injury (SCI) which recommend maintaining mean arterial pressure (MAP) at 85-90 mmHg in the days following injury. METHODS: This study examined data collected minute-by-minute to describe the pressure profile in the first 5 days following SCI in 16 patients admitted to the Intensive Care Unit at Vancouver General Hospital (40 ± 19 years, 13 M/3 F, C4-T11). MAP and intrathecal pressure (ITP) were monitored at 100 Hz by arterial and lumbar intrathecal catheters, respectively, and reported as the average of each minute. Spinal cord perfusion pressure was calculated as the difference between MAP and ITP. The minute-to-minute difference (MMdiff) of each pressure variable was calculated as the absolute difference between consecutive minutes. RESULTS: Only 24 ± 7% of MAP recordings were between 85 and 90 mmHg. Average MAP MMdiff was ~3 mmHg. The percentage of MAP recordings within target range was negatively correlated with the degree of variability (i.e. MMdiff; r = -0.64, p < 0.008) whereas higher mean MAP was correlated with greater variability (r = 0.57, p = 0.021). CONCLUSIONS: Our findings point to the 'real life' challenges in maintaining MAP in acute SCI patients. Given MAP fluctuated ~3 mmHg minute-to-minute, maintaining MAP within a 5 mmHg range with conventional volume replacement and vasopressors presents an almost impossible task for clinicians and warrants reconsideration of current management guidelines.

Correction: The influence of neurological examination timing within hours after acute traumatic spinal cord injuries: an observational study.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The influence of neurological examination timing within hours after acute traumatic spinal cord injuries: an observational study.

STUDY DESIGN: Cohort study. OBJECTIVES: It is widely accepted that the prediction of long-term neurologic outcome after traumatic spinal cord injury (SCI) can be done more accurately with neurological examinations conducted days to weeks post injury. However, modern clinical trials of neuroprotective interventions often require patients be examined and enrolled within hours. Our objective was to determine whether variability in timing of neurological examinations within 48 h after SCI is associated with differences in observations of follow-up neurologic recovery. SETTING: Level I trauma hospital. METHODS: An observational analysis testing for differences in AIS conversion rates and changes in total motor scores by neurological examination timing, controlling for potential confounders with multivariate stepwise regression. RESULTS: We included 85 patients, whose mean times from injury to baseline and follow-up examinations were 11.8 h (SD 9.8) and 208.2 days (SD 75.2), respectively. AIS conversion by 1+ grade was significantly more likely in patients examined at ≤4 h in comparison with later examination (78% versus 47%, RR = 1.66, p = 0.04), even after controlling for timing of surgery, age, and sex (OR 5.0, 95% CI 1.1-10, p = 0.04). We failed to identify any statistically significant associations for total motor score recovery in unadjusted or adjusted analyses. CONCLUSIONS: AIS grade conversion was significantly more likely in those examined ≤4 h of injury; the effect of timing on motor scores remains uncertain. Variability in neurological examination timing within hours after acute traumatic SCI may influence observations of long-term neurological recovery, which could introduce bias or lead to errors in interpretation of studies of therapeutic interventions.

Pseudarthrosis in adult and pediatric spinal deformity surgery: a systematic review of the literature and meta-analysis of incidence, characteristics, and risk factors.

We conducted a systematic review with meta-analysis and qualitative synthesis. This study aims to characterize pseudarthrosis after long-segment fusion in spinal deformity by identifying incidence rates by etiology, risk factors for its development, and common features. Pseudarthrosis can be a painful and debilitating complication of spinal fusion that may require reoperation. It is poorly characterized in the setting of spinal deformity. The MEDLINE, EMBASE, and Cochrane databases were searched for clinical research including spinal deformity patients treated with long-segment fusions reporting pseudarthrosis as a complication. Meta-analysis was performed on etiologic subsets of the studies to calculate incidence rates for pseudarthrosis. Qualitative synthesis was performed to identify characteristics of and risk factors for pseudarthrosis. The review found 162 articles reporting outcomes for 16,938 patients which met inclusion criteria. In general, the included studies were of medium to low quality according to recommended reporting standards and study design. Meta-analysis calculated an incidence of 1.4% (95% CI 0.9-1.8%) for pseudarthrosis in adolescent idiopathic scoliosis, 2.2% (95% CI 1.3-3.2%) in neuromuscular scoliosis, and 6.3% (95% CI 4.3-8.2%) in adult spinal deformity. Risk factors for pseudarthrosis include age over 55, construct length greater than 12 segments, smoking, thoracolumbar kyphosis greater than 20°, and fusion to the sacrum. Choice of graft material, pre-operative coronal alignment, post-operative analgesics, and sex have no significant impact on fusion rates. Older patients with greater deformity requiring more extensive instrumentation are at higher risk for pseudarthrosis. Overall incidence of pseudarthrosis requiring reoperation is low in adult populations and very low in adolescent populations.

'After-hours' non-elective spine surgery is associated with increased perioperative adverse events in a quaternary center.

PURPOSE: 'After-hours' non-elective spinal surgeries are frequently necessary, and often performed under sub-optimal conditions. This study aimed (1) to compare the characteristics of patients undergoing non-elective spine surgery 'After-hours' as compared to 'In-hours'; and (2) to compare the perioperative adverse events (AEs) between those undergoing non-elective spine surgery 'after-hours' as compared to 'in-hours'. METHODS: In this retrospective study of a prospective non-elective spine surgery cohort performed in a quaternary spine center, surgery was defined as 'in-hours' if performed between 0700 and 1600 h from Monday to Friday or 'after-hours' if more than 50% of the operative time occurred between 1601 and 0659 h, or if performed over the weekend. The association of 'after-hours' surgery with AEs, surgical duration, intraoperative estimated blood loss (IOBL), length of stay and in-hospital mortality was analyzed using stepwise multivariate logistic regression. RESULTS: A total of 1440 patients who underwent non-elective spinal surgery between 2009 and 2013 were included in this study. A total of 664 (46%) procedures were performed 'after-hours'. Surgical duration and IOBL were similar. About 70% of the patients operated 'after-hours' experienced at least one AE compared to 64% for the 'in-hours' group (p = 0.016). 'After-hours' surgery remained an independent predictor of AEs on multivariate analysis [adjusted OR 1.30, 95% confidence interval (CI) 1.02-1.66, p = 0.034]. In-hospital mortality increased twofold in patients operated 'after-hours' (4.4% vs. 2.1%, p = 0.013). This association lost significance on multivariate analysis (adjusted OR 1.99, 95% CI 0.98-4.06, p = 0.056). CONCLUSION: Non-elective spine surgery performed 'after-hours' is independently associated with increased risk of perioperative adverse events, length of stay and possibly, mortality. Research is needed to determine the specific factors contributing to poorer outcomes with 'after-hours' surgery and strategies to minimize this risk. These slides can be retrieved under Electronic Supplementary Material.

A prospective serial MRI study following acute traumatic cervical spinal cord injury.

PURPOSE: In acute traumatic cervical spinal cord injury (SCI) patients, we sought to characterize how objective MRI measures of injury change during the first 3 week post-injury. METHODS: Six MRI scans each were planned in 19 cervical SCI patients within the first 3 week post-injury. Length of cord edema, maximum spinal cord compression, maximum canal compromise, and presence and length of hematoma were measured. RESULTS: Length of spinal cord edema increased in the first 48 h after SCI, followed by a gradual decrease in the 3 weeks after injury. This was predominantly seen in the more severe grades of SCI. Hematoma in the spinal cord was seen in all AIS-A and B patients. CONCLUSION: This study demonstrates the dynamic nature of imaging changes on MRI in the first weeks after injury and highlights the importance of taking into account the timing of imaging when interpreting objective measures of damage.

An assessment of frailty as a tool for risk stratification in adult spinal deformity surgery.

OBJECTIVE The goal of this study was to analyze the value of an adult spinal deformity frailty index (ASD-FI) in preoperative risk stratification. Preoperative risk assessment is imperative before procedures known to have high complication rates, such as ASD surgery. Frailty has been associated with risk of complications in trauma surgery, and preoperative frailty assessments could improve the accuracy of risk stratification by providing a comprehensive analysis of patient factors that contribute to an increased risk of complications. METHODS Using 40 variables, the authors calculated frailty scores with a validated method for 417 patients (enrolled between 2010 and 2014) with a minimum 2-year follow-up in an ASD database. On the basis of these scores, the authors categorized patients as not frail (NF) (< 0.3 points), frail (0.3-0.5 points), or severely frail (SF) (> 0.5 points). The correlation between frailty category and incidence of complications was analyzed. RESULTS The overall mean ASD-FI score was 0.33 (range 0.0-0.8). Compared with NF patients (n = 183), frail patients (n = 158) and SF patients (n = 109) had longer mean hospital stays (1.2 and 1.6 times longer, respectively; p < 0.001). The adjusted odds of experiencing a major intraoperative or postoperative complication were higher for frail patients (OR 2.8) and SF patients ( 4.1) compared with NF patients (p < 0.01). For frail and SF patients, respectively, the adjusted odds of developing proximal junctional kyphosis (OR 2.8 and 3.1) were higher than those for NF patients. The SF patients had higher odds of developing pseudarthrosis (OR 13.0), deep wound infection (OR 8.0), and wound dehiscence (OR 13.4) than NF patients (p < 0.05), and they had 2.1 times greater odds of reoperation (p < 0.05). CONCLUSIONS Greater patient frailty, as measured by the ASD-FI, was associated with worse outcome in many common quality and value metrics, including greater risk of major complications, proximal junctional kyphosis, pseudarthrosis, deep wound infection, wound dehiscence, reoperation, and longer hospital stay.

Long-term outcome after selective dorsal rhizotomy in children with spastic cerebral palsy.

PURPOSE: The purpose of this study is to evaluate long-term outcomes after selective dorsal rhizotomy (SDR) for children with spastic cerebral palsy. METHODS: This is a retrospective review of a prospective database of patients who underwent SDR at British Columbia Children's Hospital. Hip adductor spasticity, hip range of motion (ROM), quadriceps strength, and motor function were assessed pre-operatively, at 6 months to 5 years and more than 10 years postoperatively. Patients were stratified by Gross Motor Function Classification System (GMFCS) level into group 1 (GMFCS II and III) and group 2 (GMFCS IV and V). RESULTS: Forty-four patients, with mean age at SDR of 4.5 years (range 2.9-7.7), were followed for a mean 14.4 years. Spasticity (Modified Ashworth Scale) decreased 1.5 (p < 0.0001) by early postoperative evaluation with further decrease at late evaluation of 0.8 (p < 0.0001). Early improvement in hip ROM of 13.7 degrees (p < 0.0001) was not sustained at late assessment. Motor function improved in both groups at early assessment but was only sustained in group 1. Group 1 increased 10.0 points (p < 0.0001) at early evaluation with subsequent decrease of 3.5, resulting in an overall increase of 6.6 (p = 0.04) from baseline. Group 2 patients had an initial increase of 8.3 [2.0, 14.6] (p = 0.01) but then declined to 4.9 below baseline (p = 0.3). CONCLUSIONS: SDR yields durable reduction in spasticity after 10 years. Early improvements in motor function are present, but at long-term follow-up, these improvements were attenuated in GMFCS II and III and were not sustained in GMFCS IV and V.

The role of resection alone in select children with intracranial ependymoma: the Canadian Pediatric Brain Tumour Consortium experience.

PURPOSE: Gross total resection (GTR) of intracranial ependymoma is an accepted goal. More controversial is radiotherapy deferral. This study reports on children treated with gross total resection who did not receive upfront adjuvant radiotherapy. METHODS: We conducted a retrospective review of children with intracranial ependymoma in 12 Canadian centers. Patients who had GTR of their tumor and no upfront radiotherapy were identified. Immunostaining was performed for Ki-67, epidermal growth factor receptor (EGFR), and EZH2 on archived tissue. The Kaplan-Meier survival analysis was performed and compared with those who had GTR followed by radiation. RESULTS: Twenty-six children were identified treated with GTR alone at diagnosis; 12 posterior fossa ependymoma (PFE) WHO grade II, and 14 supratentorial ependymoma (STE). Progression-free survival (PFS) in ependymoma treated with GTR alone at diagnosis was inferior in those with high Ki-67 or positive EZH2 immunostaining. Survival was inferior for patients less than 2 years old at diagnosis (p = 0.002). Survival was comparable to PFE WHO grade II and STE who had GTR followed by radiation (p = 0.62). Five-year PFS and overall survival (OS) of those treated with GTR alone were 60 and 70% respectively for PFE and 45 and 70% respectively for STE (p = 0.2; 0.55). CONCLUSIONS: This study suggests that there is a subset of children with certain biologic features who, in the setting of a prospective clinical trial, might be candidates for observation following GTR. Good risk factors for this approach include age of 2 years or older, low Ki-67, and negative EZH2. If relapse occurs, it may be confined to the primary site, allowing for possible salvage with GTR followed by XRT.

Out-of-hours emergent surgery for degenerative spinal disease in Canada: a retrospective cohort study from a national registry.

Background: Spinal degenerative disease represents a growing burden on our healthcare system, yet little is known about longitudinal trends in access and care. Our goal was to provide an essential portrait of surgical volume trends for degenerative spinal pathologies within Canada. Methods: The Canadian Institute for Health Information (CIHI) database was used to identify all patients receiving surgery for a degenerative spinal condition from 2006 to 2019. Trends in number of interventions, unscheduled vs scheduled hospitalizations, in-hours vs out-of-hours interventions, resource utilization and adverse events were analyzed retrospectively using linear regression models. Confidence intervals were reported in the expected count ratio scale (CR). Findings: A total of 338,629 spinal interventions and 256,360 hospitalizations between 2006 and 2019 were analyzed. The mean and SD of the annual mean age of patients was 55.5 (SD 1.6) for elective hospitalizations and 55.6 (SD 1.6) for emergent hospitalizations. The proportion of female patients was 47.8% (91,789/192,027) for elective hospitalizations and 41.4% (26,633/64,333) for emergent hospitalizations. Elective hospitalizations increased an average of 2.0% per year, with CR = 1.020 (95% CI 1.017-1.023, p < 0.0001) while emergent hospitalizations exhibited more rapid growth with an average 3.4% annually, with CR 1.034 (95% CI 1.027-1.040, p < 0.0001). «In-hours ¼ surgeries increased on average 2.7% per year, with CR 1.027 (95% CI 1.021-1.033, p < 0.0001), while « out-of-hours ¼ surgeries increased 6.1% annually, with CR 1.061 (95% CI 1.051-1.071, p < 0.0001). The resource utilization for unscheduled hospitalizations approximates two and a half times that of scheduled hospitalizations. The proportions of spinal interventions with at least one adverse event increased on average 6.3% per year, with CR 1.063 (95% CI 1.049-1.077, p < 0.0001). Interpretation: This study provides novel data critical for all providers and stakeholders. The rapid growth of emergent out-of-hours hospitalizations demonstrates that the needs of this growing patient population have far exceeded health-care resource allocations. Future studies will analyze the health-related quality of life implications of this system shift and identify demographic and socioeconomic inequities in access to surgical care. Funding: This work was funded by the Bob and Trish Saunders Spine Research Fund through The VGH and UBC Hospital Foundation. The funder of the study had no role in the study design, data collection, data analysis, data interpretation, or writing of the manuscript.

Patient-Reported Outcomes Following Surgery for Lumbar Disc Herniation: Comparison of a Universal and Multitier Health Care System.

STUDY DESIGN: Ambispective cohort study. OBJECTIVE: Canada has a government-funded universal health care system. The United States utilizes a multitier public and private system. The objective is to investigate differences in clinical outcomes between those surgically treated for lumbar disc herniation in a universal health care and multitier health system. METHODS: Surgical lumbar disc herniation patients enrolled in the Canadian Spine Outcome Research Network (CSORN) were compared with the surgical cohort enrolled in the Spine Patients Outcome Research Trial (SPORT) study. Baseline demographics and spine-related patient-reported outcomes (PROs) were compared at 3 months and 1 year post-operatively. RESULTS: The CSORN cohort consisted of 443 patients; the SPORT cohort had 763 patients. Patients in the CSORN cohort were older (46.4 ± 13.5 vs 41.0 ± 10.8, P < .001) and were more likely to be employed (69.5% vs 60.3%, P = .003). The CSORN cohort demonstrated significantly greater rates of satisfaction after surgery at 3 months (87.2% vs 64.8%, P < .0001) and 1 year (85.6% vs 69.6%, P < .0001). Improvements in back and leg pain followed similar trajectories in the two cohorts, but there was less improvement on ODI in the CSORN cohort (P < .01). On multivariable logistic regression, the CSORN cohort was a significant independent predictor of patient satisfaction at 1-year follow-up (P < .001). CONCLUSIONS: Despite less improvement on ODI, patients enrolled in CSORN, as part of a universal health care system, reported higher rates of satisfaction at 3 months and 1 year post-operatively compared to patients enrolled within a multitier health system.

Patient's expectations of surgery for lumbar degenerative spondylolisthesis: analysis by type of surgery and patient factors from the Canadian Spine Outcomes and Research Network (CSORN).

BACKGROUND CONTEXT: Preoperative expectations influence postoperative outcomes. Patients with lumbar degenerative spondylolisthesis have especially high expectations of pain relief and overall functional well-being compared to patients with lumbar stenosis. PURPOSE: The primary objective was to analyze preoperative expectations of lumbar DS patients with respect to the type of surgery proposed (decompression vs decompression and fusion). Secondarily, we aimed to assess the associations between preoperative expectations and patient and clinical factors as well as postoperative expectations fulfillment. STUDY DESIGN/SETTING: Patients were prospectively enrolled in a multicenter, prospective cohort study evaluating the assessment and management of degenerative spondylolisthesis utilizing the infrastructure of the Canadian Spine Outcomes and Research Network (CSORN) surgical registry. PATIENT SAMPLE: Patients with a diagnosis of degenerative spondylolisthesis with symptoms of neurogenic claudication or radiculopathy with or without back pain, unresponsive to nonoperative management over at least 3 months were included. Patients who underwent decompression, decompression and posterolateral fusion or decompression and interbody fusion at Canadian spine centers between January 2015 and September 2021 were included. OUTCOME MEASURES: The North American Spine Society Lumbar Spine Questionnaire was utilized for expectations measurement. The expectation questionnaire was completed following consent and before surgery and at 1 year. METHODS: Expectations for pain relief and improvements in overall functional well-being were rated on a scale of 0 to 100. Preoperative expectation in terms of pain relief and functional well-being score were calculated. Multivariate linear regression was used to evaluate the association between expected preoperative patient factors and pain relief and functional well-being. The factors associated with the most important expectation were evaluated using multivariable multinomial logistic regression. RESULTS: Three hundred fifty-two patients were included with 100 patients undergoing decompression and 252 patients also undergoing fusion. The seven items of preoperative expectations did not differ between the procedure groups nor did expected change. The mean pain relief and overall functional well-being expectation scores did not significantly differ between procedures. Higher expectations were associated with having more comorbidities [ß=-2.0 (SE 0.8), p=.020], being physically active [ß=8.4 (SE 3.2), p=.010] and having more leg pain [ß=1.6 (SE 0.7), p=.015]. Better perceived physical health measured by SF12 PCS was associated with lower expectation of pain relief [ß= -0.4 (SE 0.2), p=.039] and functional well-being [ß=-0.84 (SE 0.2), p=.001]. Better perceived mental health measured by SF12 MCS was associated with lower expectation of functional well-being [ß=-0.8 (SE 0.2), p=.001]. Postoperative expectations fulfillment did not differ between procedures. CONCLUSION: Preoperative expectations in terms of pain relief and functional well-being were similar between the two most common procedures performed, decompression ± fusion. Secondarily, higher preoperative expectations were associated with greater pain, disability and being physically active. Expectations fulfillment did not differ between procedures.

The Role of Frailty and Sarcopenia in Predicting Major Adverse Events, Length of Stay and Reoperation Following En Bloc Resection of Primary Tumours of the Spine.

STUDY DESIGN: Retrospective observational cohort study. OBJECTIVE: En bloc resection for primary tumours of the spine is associated with a high rate of adverse events (AEs). The objective was to explore the relationship between frailty/sarcopenia and major perioperative AEs, length of stay (LOS), and unplanned reoperation following en bloc resection of primary spinal tumours. METHODS: This is a unicentre study consisting of adult patients undergoing en bloc resection for a primary spine tumor. Frailty was calculated with the modified frailty index (mFI) and spine tumour frailty index (STFI). Sarcopenia was quantified with the total psoas area/vertebral body area ratio (TPA/VB) at L3 and L4. Univariable regression analysis was used to quantify the association between frailty/sarcopenia and major perioperative AEs, LOS and unplanned reoperation. RESULTS: 95 patients met the inclusion criteria. The mFI and STFI identified a frailty prevalence of 3% and 18%. Mean CT TPA/VB ratios were 1.47 (SD ± .05) and 1.83 (SD ± .06) at L3 and L4. Inter-observer reliability was .93 and .99 for CT and MRI L3 and L4 TPA/VB ratios. Unadjusted analysis demonstrated sarcopenia and mFI did not predict perioperative AEs, LOS or unplanned reoperation. Frailty defined by an STFI score ≥2 predicted unplanned reoperation for surgical site infection (SSI) (P < .05). CONCLUSIONS: The STFI was only associated with unplanned reoperation for SSI on unadjusted analysis, while the mFI and sarcopenia were not predictive of any outcome. Further studies are needed to investigate the relationship between frailty, sarcopenia and perioperative outcomes following en bloc resection of primary spinal tumors.

Generic versus disease-specific adverse event reporting: a comparison of the NSQIP and SAVES databases for the identification of acute care adverse events in adult spine surgery.

OBJECTIVE: The accurate identification and reporting of adverse events (AEs) is crucial for quality improvement. A myriad of AE systems are utilized. There is a lack of understanding of the differences between prospective versus retrospective, disease-specific versus generic, and point-of-care versus chart-abstracted systems. The objective of this study was to compare the benefits and limitations between the prospective, disease-specific, point-of-care Spine Adverse Events Severity System (SAVES) and the retrospective, generic, and chart-abstracted National Surgical Quality Improvement Program (NSQIP) for the identification and reporting of AEs in adult patients undergoing spinal surgery. METHODS: The authors conducted an observational ambidirectional cohort study of adult patients undergoing spine surgery other than for trauma between 2011 and 2019 in a quaternary spine center. Patients were identified using Current Procedural Terminology codes in the NSQIP database and matched using unique medical record numbers to their corresponding record in SAVES. The incidence of AEs and per-patient AEs as recorded in NSQIP and SAVES was the primary outcome of interest. Comparable AEs were identified by matching NSQIP AEs to equivalent ones in SAVES. Chi-square tests were used to test for significant differences in the incidence of overall and comparable AEs between the databases. RESULTS: There were 2198 patients identified in NSQIP, of whom 2033 also had complete records in SAVES. SAVES identified 5342 individual AEs in 1484 patients (73%) compared with 1291 individual AEs in 807 patients (39.7%) with the NSQIP database (p < 0.001). SAVES identified 250 intraoperative and 422 postoperative spine-specific AEs that NSQIP did not record. NSQIP captured a greater number of AEs beyond 30 days, including prolonged length of stay > 30 days, unplanned readmission, unplanned reoperation, and death later than 30 days after surgery compared with SAVES. CONCLUSIONS: SAVES captures a greater incidence of peri- and intraoperative spine-specific AEs than NSQIP, while NSQIP identifies a greater number of AEs beyond 30 days. While a prospective, disease-specific, point-of-care AE system such as SAVES is specific for guiding quality improvement in spine surgery, it incurs greater time and financial costs. Conversely, a retrospective, generic, and chart-abstracted system such as NSQIP provides equivocal cross-institutional comparability with reduced time and financial costs. Specific contextual and aim-specific needs should guide the choice and implementation of an AE system.