Outcome prediction following lumbar disc surgery: a longitudinal study of outcome trajectories, prognostic factors, and risk models.

OBJECTIVE: This study aimed to 1) describe the 2-year postoperative trajectories of leg pain and overall clinical outcome after surgery for radiculopathy, 2) identify the preoperative prognostic factors that predict trajectories representing poor clinical outcomes, and 3) develop and internally validate multivariable prognostic models to assist with clinical decision-making. METHODS: This retrospective cohort study included patients enrolled in the Canadian Spine Outcomes and Research Network who were diagnosed with lumbar disc pathology and radiculopathy and had undergone lumbar discectomy at one of 18 spine centers. Potential outcome predictors included preoperative demographic, health-related, and clinical prognostic factors. Clinical outcomes were 1) 2-year univariable latent trajectories of leg pain intensity (numeric pain rating scale) and 2) overall outcomes comprising multivariable trajectories showing the combined postoperative courses of leg and back pain intensity (numeric pain rating scale) together with pain-related disability (Oswestry Disability Index). Each outcome model identified a subgroup of patients classified as experiencing a poor outcome based on minimal change in their clinical status after surgery. Multivariable risk model performance and internal validity were evaluated with discrimination and calibration statistics based on bootstrap shrinkage with 500 resamplings. RESULTS: The authors included data from 1142 patients (47.6% female). The trajectory models identified 3 subgroups based on the patients' postoperative courses of pain or disability: 88.6% of patients in the leg pain model and 71.9% in the overall outcome model experienced a good-to-excellent outcome. The models classified 11.4% (leg pain outcome) and 28.2% (overall outcome) of patients as experiencing a poor clinical outcome, which was defined as minimal improvement in pain or disability after surgery. Eleven individual demographic, health, and clinical factors predicted patients' poor leg pain and overall outcomes. The performance of the multivariable risk model for leg pain was inadequate, while the overall outcome model had acceptable discrimination, calibration, and internal validity for predicting a poor surgical outcome. CONCLUSIONS: Patients with lumbar radiculopathy experience heterogeneous postoperative trajectories of pain and disability after lumbar discectomy. Individual preoperative factors are associated with postoperative outcomes and can be combined within a multivariable risk model to predict overall patient outcome. These results may inform clinical practice but require external validation before confident clinical implementation.

Satisfaction in surgically treated patients with degenerative cervical myelopathy: an observational study from the canadian spine outcomes and research network.

BACKGROUND CONTEXT: Healthcare reimbursement is evolving towards a value-based model, entwined and emphasizing patient satisfaction. Factors associated with satisfaction after degenerative cervical myelopathy (DCM) surgery have not been previously established. PURPOSE: Our primary objective was to ascertain satisfaction rates and satisfaction predictors at 3 and 12 months following surgical treatment for DCM. DESIGN: This is a prospective cohort study within Canadian Spine Outcomes and Research Network (CSORN). PATIENT SAMPLE: Patients in the study were surgically treated for DCM patients who completed 3-month and 12-month follow-ups within CSORN between 2015 and 2021. OUTCOME MEASURES: Data analyzed included patient demographic, surgical variables, patient-reported outcomes (NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS, ED-5Q, PHQ-8), MJOA and self-reported satisfaction on a Likert scale. METHODS: Multivariable regression analysis was conducted to identify significant factors associated with satisfaction, address multicollinearity and ensure predictive accuracy. This process was conducted separately for the 3-month and 12-month follow-ups. RESULTS: Six hundred and sixty-three patients were included, with an average age of 60, and an even distribution across MJOA scores (mild, moderate, severe). At 3-month and 12-month follow-up, satisfaction rates were 86% and 82%, respectively. At 12 months, logistic regression showed the odds of being satisfied varied by +24%, -3%, -10%, -14%, +3%, and +12% for each 1-point change between baseline and 12 months in MJOA, NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS. Satisfaction increased 11-fold for each 0.1-point increased in ED-5Q from baseline to 12 months. At baseline, for every 1-point increase in SF-12-MCS, the odds of being satisfied increased by 7%. At 3 months, all PROs (except for NRS-AP change and baseline SF-12-MCS) predicted satisfaction. All logistic regression analyses demonstrated excellent predictive accuracy, with the highest 12-month AUC of 0.86 (95%CI = 0.81-0.90). No patient demographic or surgical factors influenced satisfaction. CONCLUSION: Improvement in Patient Reported Outcomes and MJOA are strongly associated with patient satisfaction after surgery for DCM. The only baseline PRO associated with 12-months satisfaction was SF-12-MCS. No modifiable patient baseline characteristic or surgical variables were associated with satisfaction.

Preoperative expectations of patients with degenerative cervical myelopathy: an observational study from the Canadian Spine Outcomes and Research Network.

BACKGROUND: Despite an abundance of literature on degenerative cervical myelopathy (DCM), little is known about preoperative expectations of these patients. PURPOSE: The primary objective was to describe patient preoperative expectations. Secondary objectives included identifying patient characteristics associated with high preoperative expectations and to determine if expectations varied depending on myelopathy severity. STUDY DESIGN: This was a retrospective study of a prospective multicenter, observational cohort of patients with DCM. PATIENT SAMPLE: Patients who consented to undergo surgical treatment between January 2019 and September 2022 were included. OUTCOMES MEASURES: An 11-domain expectation questionnaire was completed preoperatively whereby patients quantified the expected change in each domain. METHODS: The most important expected change was captured. A standardized expectation score was calculated as the sum of each expectation divided by the maximal possible score. The high expectation group was defined by patients who had an expectation score above the 75th percentile. Predictors of patients with high expectations were determined using multivariable logistic regression models. RESULTS: There were 262 patients included. The most important patient expectation was preventing neurological worsening (40.8%) followed by improving balance when standing or walking (14.5%), improving independence in everyday activities (10.3%), and relieving arm tingling, burning and numbness (10%). Patients with mild myelopathy were more likely to select no worsening as the most important expected change compared to patients with severe myelopathy (p<.01). Predictors of high patient expectations were: having fewer comorbidities (OR -0.30 for every added comorbidity, 95% CI -0.59 to -0.10, p=.01), a shorter duration of symptoms (OR 0.92, 95% CI 0.35-1.19, p=.02), no contribution from "failure of other treatments" on the decision to undergo surgery (OR 1.49, 95% CI 0.56-2.71, p=.02) and more severe neck pain (OR 0.19 for 1 point increase, 95% CI 0.05-0.37, p=.01). CONCLUSIONS: Most patients undergoing surgery for DCM expect prevention of neurological decline, better functional status, and improvement in their myelopathic symptoms. Stopping neurological deterioration is the most important expected outcomes by patients.

A Clinical Practice Guideline on the Timing of Surgical Decompression and Hemodynamic Management of Acute Spinal Cord Injury and the Prevention, Diagnosis, and Management of Intraoperative Spinal Cord Injury: Introduction, Rationale, and Scope.

STUDY DESIGN: Protocol for the development of clinical practice guidelines following the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards. OBJECTIVES: Acute SCI or intraoperative SCI (ISCI) can have devastating physical and psychological consequences for patients and their families. The treatment of SCI has dramatically evolved over the last century as a result of preclinical and clinical research that has addressed important knowledge gaps, including injury mechanisms, disease pathophysiology, medical management, and the role of surgery. In an acute setting, clinicians are faced with critical decisions on how to optimize neurological recovery in patients with SCI that include the role and timing of surgical decompression and the best strategies for hemodynamic management. The lack of consensus surrounding these treatments has prevented standardization of care across centers and has created uncertainty with respect to how to best manage patients with SCI. ISCI is a feared complication that can occur in the best of hands. Unfortunately, there are no systematic reviews or clinical practice guidelines to assist spine surgeons in the assessment and management of ISCI in adult patients undergoing spinal surgery. Given these limitations, it is the objective of this initiative to develop evidence-based recommendations that will inform the management of both SCI and ISCI. This protocol describes the rationale for developing clinical practice guidelines on (i) the timing of surgical decompression in acute SCI; (ii) the hemodynamic management of acute SCI; and (iii) the prevention, identification, and management of ISCI in patients undergoing surgery for spine-related pathology. METHODS: Systematic reviews were conducted according to PRISMA standards in order to summarize the current body of evidence and inform the guideline development process. The guideline development process followed the approach proposed by the GRADE working group. Separate multidisciplinary, international groups were created to perform the systematic reviews and formulate the guidelines. All potential conflicts of interest were vetted in advance. The sponsors exerted no influence over the editorial process or the development of the guidelines. RESULTS: This process resulted in both systematic reviews and clinical practice guidelines/care pathways related to the role and timing of surgery in acute SCI; the optimal hemodynamic management of acute SCI; and the prevention, diagnosis and management of ISCI. CONCLUSIONS: The ultimate goal of this clinical practice guideline initiative was to develop evidence-based recommendations for important areas of controversy in SCI and ISCI in hopes of improving neurological outcomes, reducing morbidity, and standardizing care across settings. Throughout this process, critical knowledge gaps and future directions were also defined.

Accuracy of Intraoperative Neuromonitoring in the Diagnosis of Intraoperative Neurological Decline in the Setting of Spinal Surgery-A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: In an effort to prevent intraoperative neurological injury during spine surgery, the use of intraoperative neurophysiological monitoring (IONM) has increased significantly in recent years. Using IONM, spinal cord function can be evaluated intraoperatively by recording signals from specific nerve roots, motor tracts, and sensory tracts. We performed a systematic review and meta-analysis of diagnostic test accuracy (DTA) studies to evaluate the efficacy of IONM among patients undergoing spine surgery for any indication. METHODS: The current systematic review and meta-analysis was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis statement for Diagnostic Test Accuracy Studies (PRISMA-DTA) and was registered on PROSPERO. A comprehensive search was performed using MEDLINE, EMBASE and SCOPUS for all studies assessing the diagnostic accuracy of neuromonitoring, including somatosensory evoked potential (SSEP), motor evoked potential (MEP) and electromyography (EMG), either on their own or in combination (multimodal). Studies were included if they reported raw numbers for True Positives (TP), False Negatives (FN), False Positives (FP) and True Negative (TN) either in a 2 × 2 contingency table or in text, and if they used postoperative neurologic exam as a reference standard. Pooled sensitivity and specificity were calculated to evaluate the overall efficacy of each modality type using a bivariate model adapted by Reitsma et al, for all spine surgeries and for individual disease groups and regions of spine. The risk of bias (ROB) of included studies was assessed using the quality assessment tool for diagnostic accuracy studies (QUADAS-2). RESULTS: A total of 163 studies were included; 52 of these studies with 16,310 patients reported data for SSEP, 68 studies with 71,144 patients reported data for MEP, 16 studies with 7888 patients reported data for EMG and 69 studies with 17,968 patients reported data for multimodal monitoring. The overall sensitivity, specificity, DOR and AUC for SSEP were 71.4% (95% CI 54.8-83.7), 97.1% (95% CI 95.3-98.3), 41.9 (95% CI 24.1-73.1) and .899, respectively; for MEP, these were 90.2% (95% CI 86.2-93.1), 96% (95% CI 94.3-97.2), 103.25 (95% CI 69.98-152.34) and .927; for EMG, these were 48.3% (95% CI 31.4-65.6), 92.9% (95% CI 84.4-96.9), 11.2 (95% CI 4.84-25.97) and .773; for multimodal, these were found to be 83.5% (95% CI 81-85.7), 93.8% (95% CI 90.6-95.9), 60 (95% CI 35.6-101.3) and .895, respectively. Using the QUADAS-2 ROB analysis, of the 52 studies reporting on SSEP, 13 (25%) were high-risk, 10 (19.2%) had some concerns and 29 (55.8%) were low-risk; for MEP, 8 (11.7%) were high-risk, 21 had some concerns and 39 (57.3%) were low-risk; for EMG, 4 (25%) were high-risk, 3 (18.75%) had some concerns and 9 (56.25%) were low-risk; for multimodal, 14 (20.3%) were high-risk, 13 (18.8%) had some concerns and 42 (60.7%) were low-risk. CONCLUSIONS: These results indicate that all neuromonitoring modalities have diagnostic utility in successfully detecting impending or incident intraoperative neurologic injuries among patients undergoing spine surgery for any condition, although it is clear that the accuracy of each modality differs.PROSPERO Registration Number: CRD42023384158.

An Update of a Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on the Role and Timing of Decompressive Surgery.

STUDY DESIGN: Clinical practice guideline development. OBJECTIVES: Acute spinal cord injury (SCI) can result in devastating motor, sensory, and autonomic impairment; loss of independence; and reduced quality of life. Preclinical evidence suggests that early decompression of the spinal cord may help to limit secondary injury, reduce damage to the neural tissue, and improve functional outcomes. Emerging evidence indicates that "early" surgical decompression completed within 24 hours of injury also improves neurological recovery in patients with acute SCI. The objective of this clinical practice guideline (CPG) is to update the 2017 recommendations on the timing of surgical decompression and to evaluate the evidence with respect to ultra-early surgery (in particular, but not limited to, <12 hours after acute SCI). METHODS: A multidisciplinary, international, guideline development group (GDG) was formed that consisted of spine surgeons, neurologists, critical care specialists, emergency medicine doctors, physical medicine and rehabilitation professionals, as well as individuals living with SCI. A systematic review was conducted based on accepted methodological standards to evaluate the impact of early (within 24 hours of acute SCI) or ultra-early (in particular, but not limited to, within 12 hours of acute SCI) surgery on neurological recovery, functional outcomes, administrative outcomes, safety, and cost-effectiveness. The GRADE approach was used to rate the overall strength of evidence across studies for each primary outcome. Using the "evidence-to-recommendation" framework, recommendations were then developed that considered the balance of benefits and harms, financial impact, patient values, acceptability, and feasibility. The guideline was internally appraised using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool. RESULTS: The GDG recommended that early surgery (≤24 hours after injury) be offered as the preferred option for adult patients with acute SCI regardless of level. This recommendation was based on moderate evidence suggesting that patients were 2 times more likely to recover by ≥ 2 ASIA Impairment Score (AIS) grades at 6 months (RR: 2.76, 95% CI 1.60 to 4.98) and 12 months (RR: 1.95, 95% CI 1.26 to 3.18) if they were decompressed within 24 hours compared to after 24 hours. Furthermore, patients undergoing early surgery improved by an additional 4.50 (95% 1.70 to 7.29) points on the ASIA Motor Score compared to patients undergoing surgery after 24 hours post-injury. The GDG also agreed that a recommendation for ultra-early surgery could not be made on the basis of the current evidence because of the small sample sizes, variable definitions of what constituted ultra-early in the literature, and the inconsistency of the evidence. CONCLUSIONS: It is recommended that patients with an acute SCI, regardless of level, undergo surgery within 24 hours after injury when medically feasible. Future research is required to determine the differential effectiveness of early surgery in different subpopulations and the impact of ultra-early surgery on neurological recovery. Moreover, further work is required to define what constitutes effective spinal cord decompression and to individualize care. It is also recognized that a concerted international effort will be required to translate these recommendations into policy.

Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis.

STUDY DESIGN: Mixed-methods approach. OBJECTIVES: Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. METHODS: A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. RESULTS: The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. CONCLUSIONS: ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

A Clinical Practice Guideline for Prevention, Diagnosis and Management of Intraoperative Spinal Cord Injury: Recommendations for Use of Intraoperative Neuromonitoring and for the Use of Preoperative and Intraoperative Protocols for Patients Undergoing Spine Surgery.

STUDY DESIGN: Development of a clinical practice guideline following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process. OBJECTIVE: The objectives of this study were to develop guidelines that outline the utility of intraoperative neuromonitoring (IONM) to detect intraoperative spinal cord injury (ISCI) among patients undergoing spine surgery, to define a subset of patients undergoing spine surgery at higher risk for ISCI and to develop protocols to prevent, diagnose, and manage ISCI. METHODS: All systematic reviews were performed according to PRISMA standards and registered on PROSPERO. A multidisciplinary, international Guidelines Development Group (GDG) reviewed and discussed the evidence using GRADE protocols. Consensus was defined by 80% agreement among GDG members. A systematic review and diagnostic test accuracy (DTA) meta-analysis was performed to synthesize pooled evidence on the diagnostic accuracy of IONM to detect ISCI among patients undergoing spinal surgery. The IONM modalities evaluated included somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), electromyography (EMG), and multimodal neuromonitoring. Utilizing this knowledge and their clinical experience, the multidisciplinary GDG created recommendations for the use of IONM to identify ISCI in patients undergoing spine surgery. The evidence related to existing care pathways to manage ISCI was summarized and based on this a novel AO Spine-PRAXIS care pathway was created. RESULTS: Our recommendations are as follows: (1) We recommend that intraoperative neurophysiological monitoring be employed for high risk patients undergoing spine surgery, and (2) We suggest that patients at "high risk" for ISCI during spine surgery be proactively identified, that after identification of such patients, multi-disciplinary team discussions be undertaken to manage patients, and that an intraoperative protocol including the use of IONM be implemented. A care pathway for the prevention, diagnosis, and management of ISCI has been developed by the GDG. CONCLUSION: We anticipate that these guidelines will promote the use of IONM to detect and manage ISCI, and promote the use of preoperative and intraoperative checklists by surgeons and other team members for high risk patients undergoing spine surgery. We welcome teams to implement and evaluate the care pathway created by our GDG.

Prevention, Diagnosis, and Management of Intraoperative Spinal Cord Injury in the Setting of Spine Surgery: A Proposed Care Pathway.

STUDY DESIGN: This study is a mixed methods approach. OBJECTIVES: Intraoperative spinal cord injury (ISCI) is a challenging complication in spine surgery. Intra-operative neuromonitoring (IONM) has been developed to detect changes in neural function. We report on the first multidisciplinary, international effort through AO Spine and the Praxis Spinal Cord Institute to develop a comprehensive guideline and care pathway for the prevention, diagnosis, and management of ISCI. METHODS: Three literature reviews were registered on PROSPERO (CRD 42022298841) and performed according to PRISMA guidelines: (1) Definitions, frequency, and risk factors for ISCI, (2) Meta-analysis of the accuracy of IONM for diagnosis of ISCI, (3) Reported management approaches for ISCI and related events. The results were presented in a consensus session to decide the definition of IONM and recommendation of its use in high-risk cases. Based on a literature review of management strategies for ISCI, an intra-operative checklist and overall care pathway was developed by the study team. RESULTS: An operational definition and high-risk patient categories for ISCI were established. The reported incidence of deficits was documented to be higher in intramedullary tumour spine surgery. Multimodality IONM has a high sensitivity and specificity. A guideline recommendation of IONM to be employed for high-risk spine cases was made. The different sections of the intraoperative checklist include surgery, anaesthetic and neurophysiology. The care pathway includes steps (1) initial clinical assessment, (2) pre-operative planning, (3) surgical/anaesthetic planning, (4) intra-operative management, and (5) post-operative management. CONCLUSIONS: This is the first evidence based comprehensive guideline and care pathway for ISCI using the GRADE methodology. This will facilitate a reduction in the incidence of ISCI and improved outcomes from this complication. We welcome the wide implementation and validation of these guidelines and care pathways in prospective, multicentre studies.

The 2023 AO Spine-Praxis Guidelines in Acute Spinal Cord Injury: What Have We Learned? What Are the Critical Knowledge Gaps and Barriers to Implementation?

STUDY DESIGN: Narrative summary of the 2023 AO Spine-Praxis clinical practice guidelines for management in acute spinal cord injury (SCI). OBJECTIVES: The objective of this article is to summarize the key findings of the clinical practice guidelines for the optimal management of traumatic and intraoperative SCI (ISCI). This article will also highlight potential knowledge translation opportunities for each recommendation and discuss important knowledge gaps and areas of future research. METHODS: Systematic reviews were conducted according to accepted methodological standards to evaluate the current body of evidence and inform the guideline development process. The summarized evidence was reviewed by a multidisciplinary guidelines development group that consisted of international multidisciplinary stakeholders. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of the evidence for each critical outcome and the "evidence to recommendation" framework was used to formulate the final recommendations. RESULTS: The key recommendations regarding the timing of surgical decompression, hemodynamic management, and the prevention, diagnosis, and management of ISCI are summarized. While a strong recommendation was made for early surgery, further prospective research is required to define what constitutes sufficient surgical decompression, examine the role of ultra-early surgery, and assess the impact of early surgery in different SCI phenotypes, including central cord syndrome. Furthermore, additional investigation is required to evaluate the impact of mean arterial blood pressure targets on neurological recovery and to determine the utility of spinal cord perfusion pressure measurements. Finally, there is a need to examine the role of neuroprotective agents for the treatment of ISCI and to prospectively validate the new AO Spine-Praxis care pathway for the prevention, diagnosis, and management of ISCI. To optimize the translation of these guidelines into practice, important barriers to their implementation, particularly in underserved areas, need to be explored. Ultimately, these recommendations will help to establish more personalized approaches to care for SCI patients. CONCLUSIONS: The recommendations from the 2023 AO Spine-Praxis guidelines not only highlight the current best practice in the management of SCI, but reveal critical knowledge gaps and barriers to implementation that will help to guide further research efforts in SCI.

The Management of Intraoperative Spinal Cord Injury - A Scoping Review.

STUDY DESIGN: Scoping Review. OBJECTIVE: To review the literature and summarize information on checklists and algorithms for responding to intraoperative neuromonitoring (IONM) alerts and management of intraoperative spinal cord injuries (ISCIs). METHODS: MEDLINE® was searched from inception through January 26, 2022 as were sources of grey literature. We attempted to obtain guidelines and/or consensus statements from the following sources: American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), American Academy of Neurology (AAN), American Clinical Neurophysiology Society, NASS (North American Spine Society), and other spine surgery organizations. RESULTS: Of 16 studies reporting on management strategies for ISCIs, two were publications of consensus meetings which were conducted according to the Delphi method and eight were retrospective cohort studies. The remaining six studies were narrative reviews that proposed intraoperative checklists and management strategies for IONM alerts. Of note, 56% of included studies focused only on patients undergoing spinal deformity surgery. Intraoperative considerations and measures taken in the event of an ISCI are divided and reported in three categories of i) Anesthesiologic, ii) Neurophysiological/Technical, and iii) Surgical management strategies. CONCLUSION: There is a paucity of literature on comparative effectiveness and harms of management strategies in response to an IONM alert and possible ISCI. There is a pressing need to develop a standardized checklist and care pathway to avoid and minimize the risk of postoperative neurologic sequelae.

An Overview of the Methodology Used to Develop Clinical Practice Guidelines for the Management of Acute and Intraoperative Spinal Cord Injury.

STUDY DESIGN: An overview of the methods used to develop clinical practice guidelines (CPGs). OBJECTIVES: Acute spinal cord injury (SCI) and intraoperative SCI (ISCI) can have devastating physical and psychological consequences for patients and their families. To date, there are several studies that have discussed the diagnostic and management strategies for both SCI and ISCI. CPGs in SCI help to distill and translate the current evidence into actionable recommendations, standardize care across centers, optimize patient outcomes, and reduce costs and unnecessary interventions. Furthermore, they can be used by patients to assist in making decisions about certain treatments and by policy makers to inform allocation of resources. The objective of this article is to summarize the methods used to develop CPGs for the timing of surgery and hemodynamic management of acute SCI, as well as the identification and treatment of ISCI. METHODS: The CPGs were developed using standards established by the Institute of Medicine (now the National Academy of Medicine), the Guideline International Network and several other organizations. Systematic reviews were conducted according to accepted methodological standards (eg, Institute of Medicine, Agency for Healthcare Research and Quality and Patient-Centered Outcomes Research Institute) in order to summarize the current body of evidence and inform the guideline development process. Protocols for each guideline were created. A multidisciplinary guideline development group (GDG) was formed that included individuals living with SCI as well as clinicians from the broad range of specialties that encounter patients with SCI: spine or trauma surgeons, critical care physicians, rehabilitation specialists, neurologists, anesthesiologists and other healthcare professionals. Individuals living with SCI were also included in the GDG. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to rate the certainty of the evidence for each critical outcome. The "evidence to recommendation" framework was then used to translate the evidence obtained from the systematic review to an actionable recommendation. This framework provides structure when assessing the body of evidence and considers several additional factors when rating the strength of the recommendation, including the magnitude of benefits and harms, patient preferences, resource use, health equities, acceptability and feasibility. Finally, the CPGs were appraised both internally and externally. RESULTS: The results of the CPGs for SCI are provided in separate articles in this focus issue. CONCLUSIONS: Development of these CPGs for SCI followed the methodology proposed by the Institute of Medicine the Guideline International Network and the GRADE Working Group. It is anticipated that these CPGs will assist clinicians implement the best evidence into practice and facilitate shared-decision making with patients.

Timing of Decompressive Surgery in Patients With Acute Spinal Cord Injury: Systematic Review Update.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Surgical decompression is a cornerstone in the management of patients with traumatic spinal cord injury (SCI); however, the influence of the timing of surgery on neurological recovery after acute SCI remains controversial. This systematic review aims to summarize current evidence on the effectiveness, safety, and cost-effectiveness of early (≤24 hours) or late (>24 hours) surgery in patients with acute traumatic SCI for all levels of the spine. Furthermore, this systematic review aims to evaluate the evidence with respect to the impact of ultra-early surgery (earlier than 24 hours from injury) on these outcomes. METHODS: A systematic search of the literature was performed using the MEDLINE database (PubMed), Cochrane database, and EMBASE. Two reviewers independently screened the citations from the search to determine whether an article satisfied predefined inclusion and exclusion criteria. For all key questions, we focused on primary studies with the least potential for bias and those that controlled for baseline neurological status and specified time from injury to surgery. Risk of bias of each article was assessed using standardized tools based on study design. Finally, the overall strength of evidence for the primary outcomes was assessed using the GRADE approach. Data were synthesized both qualitatively and quantitively using meta-analyses. RESULTS: Twenty-one studies met inclusion and exclusion criteria and formed the evidence base for this review update. Seventeen studies compared outcomes between patients treated with early (≤24 hours from injury) compared to late (>24 hours) surgical decompression. An additional 4 studies evaluated even earlier time frames: <4, <5, <8 or <12 hours. Based on moderate evidence, patients were 2 times more likely to recover by ≥ 2 grades on the ASIA Impairment Score (AIS) at 6 months (RR: 2.76, 95% CI 1.60 to 4.98) and 12 months (RR: 1.95, 95% CI 1.26 to 3.18) if they were decompressed within 24 hours compared to after 24 hours. Furthermore, moderate evidence suggested that patients receiving early decompression had an additional 4.50 (95% CI 1.70 to 7.29) point improvement on the ASIA motor score. With respect to administrative outcomes, there was low evidence that early decompression may decrease acute hospital length of stay. In terms of safety, there was moderate evidence that suggested the rate of major complications does not differ between patients undergoing early compared to late surgery. Furthermore, there was no difference in rates of mortality, surgical device-related complications, sepsis/systemic infection or neurological deterioration based on timing of surgery. Firm conclusions were not possible with respect to the impact of ultra-early surgery on neurological, functional or safety outcomes given the poor-quality studies, imprecision and the overlap in the time frames examined. CONCLUSIONS: This review provides an evidence base to support the update on clinical practice guidelines related to the timing of surgical decompression in acute SCI. Overall, the strength of evidence was moderate that early surgery (≤24 hours from injury) compared to late (>24 hours) results in clinically meaningful improvements in neurological recovery. Further studies are required to delineate the role of ultra-early surgery in patients with acute SCI.

AO Spine/Praxis Clinical Practice Guidelines for the Management of Acute Spinal Cord Injury: An Introduction to a Focus Issue.

STUDY DESIGN: Narrative overview and summary. OBJECTIVES: The objective of this introductory manuscript is to provide an overview of the effort that was undertaken to establish clinical practice guidelines for a number of important topics in spinal cord injury (SCI). These topics included: 1. The role and timing of surgical decompression after acute traumatic SCI; 2. The hemodynamic management of acute traumatic SCI; and 3. The definition, diagnosis, and management of intra-operative SCI. Here, we introduce the rationale for the guidelines, the methodology utilized, and summarize how the topics are addressed within various manuscripts of this Focus Issue. METHODS: The key clinical questions were defined using the PICO format for treatment reviews (patient; intervention; comparison; outcomes) or PPO format (patient, prognostic factor, outcomes) for risk factor review. Multi-disciplinary, international guideline development groups (GDGs) were established to evaluate and collate the available evidence in a rigorous, systematic manner, followed by a review of systematically obtained evidence within the framework of the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria and application of the Evidence to Decision process. Consensus meetings, using a modified Delphi approach, were held with the multidisciplinary, international GDGs using online video-conferencing technology and anonymous voting to develop the final recommendations for each of the topics addressed. All systematic review protocols followed PRISMA standards and were registered on PROSPERO; all potential conflicts were vetted in an open and transparent manner. The funders (AO Spine and Praxis Spinal Cord Institute) had no influence over editorial content or the guidelines process). RESULTS: Updated guidelines were established for the timing of surgical decompression after acute SCI, with surgical decompression within 24 hours of injury now "recommended" as a treatment option. Updated guidelines were also established for hemodynamic management, with an expanded target range for mean arterial pressure (MAP) of 75-80 to 90-95 mmHg for between 3 to 7 days post-injury now "suggested" as a treatment option. The available literature mandated scoping and systematic reviews on the topic of intra-operative SCI, and this resulted in manuscripts to address the definition, frequency, and risk factors, to define the role of intra-operative neuromonitoring, and to suggest an evidence-based care pathway for management. CONCLUSION: A rigorous process following GRADE standards was undertaken to review the available evidence and establish guideline recommendations around the role and timing of surgery in acute SCI, optimal hemodynamic management of acute SCI and the prevention, diagnosis and management of intraoperative SCI. This effort also identified key knowledge gaps and future directions for study, which will serve to refine these recommendations in the future.

The Effects of Peri-Operative Adverse Events on Clinical and Patient-Reported Outcomes After Surgery for Degenerative Cervical Myelopathy: An Observational Cohort Study from the Canadian Spine Outcomes and Research Network.

BACKGROUND AND OBJECTIVES: There is a lack of data examining the effects of perioperative adverse events (AEs) on long-term outcomes for patients undergoing surgery for degenerative cervical myelopathy. We aimed to investigate associations between the occurrence of perioperative AEs and coprimary outcomes: (1) modified Japanese Orthopaedic Association (mJOA) score and (2) Neck Disability Index (NDI) score. METHODS: We analyzed data from 800 patients prospectively enrolled in the Canadian Spine Outcomes and Research Network multicenter observational study. The Spine AEs Severity system was used to collect intraoperative and postoperative AEs. Patients were assessed at up to 2 years after surgery using the NDI and the mJOA scale. We used a linear mixed-effect regression to assess the influence of AEs on longitudinal outcome measures as well as multivariable logistic regression to assess factors associated with meeting minimal clinically important difference (MCID) thresholds at 1 year. RESULTS: There were 167 (20.9%) patients with minor AEs and 36 (4.5%) patients with major AEs. The occurrence of major AEs was associated with an average increase in NDI of 6.8 points (95% CI: 1.1-12.4, P = .019) and reduction of 1.5 points for mJOA scores (95% CI: -2.3 to -0.8, P < .001) up to 2 years after surgery. Occurrence of major AEs reduced the odds of patients achieving MCID targets at 1 year after surgery for mJOA (odds ratio 0.23, 95% CI: 0.086-0.53, P = .001) and for NDI (odds ratio 0.34, 95% CI: 0.11-0.84, P = .032). CONCLUSION: Major AEs were associated with reduced functional gains and worse recovery trajectories for patients undergoing surgery for degenerative cervical myelopathy. Occurrence of major AEs reduced the probability of achieving mJOA and NDI MCID thresholds at 1 year. Both minor and major AEs significantly increased health resource utilization by reducing the proportion of discharges home and increasing length of stay.

Anterior vs Posterior Surgery for Patients With Degenerative Cervical Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

BACKGROUND AND OBJECTIVES: The advantages and disadvantages of anterior vs posterior surgical approaches for patients with progressive degenerative cervical myelopathy (DCM) remain uncertain. Our primary objective was to evaluate patient-reported disability at 1 year after surgery. Our secondary objectives were to evaluate differences in patient profiles selected for each approach in routine clinical practice and to compare neurological function, neck and arm pain, health-related quality of life, adverse events, and rates of reoperations. METHODS: We analyzed data from patients with DCM who were enrolled in an ongoing multicenter prospective observational cohort study. We controlled for differences in baseline characteristics and numbers of spinal levels treated using multivariable logistic regression. Adverse events were collected according to the Spinal Adverse Events Severity protocol. RESULTS: Among 559 patients, 261 (47%) underwent anterior surgery while 298 (53%) underwent posterior surgery. Patients treated posteriorly had significantly worse DCM severity and a greater number of vertebral levels involved. After adjusting for confounders, there was no significant difference between approaches for odds of achieving the minimum clinically important difference for the Neck Disability Index (odds ratio 1.23, 95% CI 0.82 to 1.86, P = .31). There was also no significant difference for change in modified Japanese Orthopedic Association scores, and differences in neck and arm pain and health-related quality of life did not exceed minimum clinically important differences. Patients treated anteriorly experienced greater rates of dysphagia, whereas patients treated posteriorly experienced greater rates of wound complications, neurological complications, and reoperations. CONCLUSION: Patients selected for posterior surgery had worse DCM and a greater number of vertebral levels involved. Despite this, anterior and posterior surgeries were associated with similar improvements in disability, neurological function, pain, and quality of life. Anterior surgery had a more favorable profile of adverse events, which suggests it might be a preferred option when feasible.

Stand-Alone Anchored Spacer vs Anterior Plate Construct in the Management of Adjacent Segment Disease after Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis of Comparative Studies.

STUDY DESIGN: Systematic Review and Meta-Analysis. OBJECTIVES: This study aimed to evaluate the clinical and radiological outcomes of surgically treated adjacent segment disease (ASDis) following ACDF with either anterior plate construct (APC) or stand-alone anchored spacers (SAAS). METHOD: Multiple databases were searched until December 2022 for pertinent studies. The primary outcome was health-related quality of life outcomes [JOA, NDI, and VAS], whereas, the secondary outcomes included operative characteristics [estimated blood loss (EBL) and operative time (OT)], radiological outcomes [C2-C7 Cobb angle, disc height index (DHI) changes, fusion rate], and complications. RESULTS: A total of 5 studies were included, comprising 210 patients who had been surgically treated for cervical ASDis. Among them, 113 received APC, and 97 received SAAS. Postoperative dysphagia was significantly higher in the APC group [47% vs 11%, OR = 7.7, 95% CI = 3.1-18.9, P < .05]. Similarly, operative time and blood loss were higher in the APC group compared to the SAAS group; [MD = 16.96, 95% CI = 7.87-26.06, P < .05] and [MD = 5.22, 95% CI = .35 - 10.09, P < .05], respectively. However, there was no difference in the rate of prolonged dysphagia and clinical outcomes in terms of JOA, NDI, and VAS. Furthermore, there was no difference in the radiological parameters including the C2-7 Cobb angle and DHI as well as the fusion rate. CONCLUSION: Our meta-analysis demonstrated that both surgical techniques (APC and SAAS) are effective in treating ASDis. However, with low certainty of the evidence, considering patients are at high risk of dysphagia following revision cervical spine surgery SAAS may be the preferred choice.

Annual incidence and assessment of risk factors for early-onset deep surgical site infection following primary total knee arthroplasty in osteoarthritis.

Aims: This study aims to determine difference in annual rate of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis, and to identify risk factors that may be associated with infection. Methods: This is a retrospective population-based cohort study using prospectively collected patient-level data between 1 January 2013 and 1 March 2020. The diagnosis of deep SSI was defined as per the Centers for Disease Control/National Healthcare Safety Network criteria. The Mann-Kendall Trend test was used to detect monotonic trends in annual rates of early-onset deep SSI over time. Multiple logistic regression was used to analyze the effect of different patient, surgical, and healthcare setting factors on the risk of developing a deep SSI within 90 days from surgery for patients with complete data. We also report 90-day mortality. Results: A total of 39,038 patients underwent primary TKA for osteoarthritis during the study period. Of these, 275 patients developed a deep SSI within 90 days of surgery, representing a cumulative incidence of 0.7%. The annual infection rate did not significantly decrease over the seven-year study period (p = 0.162). Overall, 13,885 (35.5%) cases were excluded from the risk analysis due to missing data. Risk factors associated with early-onset deep SSI included male sex, American Society of Anesthesiologists grade ≥ 3, blood transfusion, acute length of stay, and surgeon volume < 30 TKAs/year. Early-onset deep SSI was not associated with increased 90-day mortality. Conclusion: This study establishes a reliable baseline infection rate for early-onset deep SSI after TKA for osteoarthritis using robust Infection Prevention and Control surveillance data, and identifies several potentially modifiable risk factors.

Predictors of Recovery Following Lumbar Microdiscectomy for Sciatica: A Systematic Review and Meta-Analysis of Observational Studies.

Chronic post-surgical pain is reported by up to 40% of patients after lumbar microdiscectomy for sciatica, a complaint associated with disability and loss of productivity. We conducted a systematic review of observational studies to explore factors associated with persistent leg pain and impairments after microdiscectomy for sciatica. We searched eligible studies in MEDLINE, Embase, and CINAHL that explored, in an adjusted model, predictors of persistent leg pain, physical impairment, or failure to return to work after microdiscectomy for sciatica. When possible, we pooled estimates of association using random-effects models using the Grading of Recommendations Assessment, Development, and Evaluation approach. Moderate-certainty evidence showed that the female sex probably has a small association with persistent post-surgical leg pain (odds ratio (OR) = 1.15, 95% confidence interval (CI) = 0.63 to 2.08; absolute risk increase (ARI) = 1.8%, 95% CI = -4.7% to 11.3%), large association with failure to return to work (OR = 2.79, 95% CI = 1.27 to 6.17; ARI = 10.6%, 95% CI = 1.8% to 25.2%), and older age is probably associated with greater postoperative disability (ß = 1.47 points on the 100-point Oswestry Disability Index for every 10-year increase from age (>/=18 years), 95% CI = -4.14 to 7.28). Among factors that were not possible to pool, two factors showed promise for future study, namely, legal representation and preoperative opioid use, which showed large associations with worse outcomes after surgery. The moderate-certainty evidence showed female sex is probably associated with persistent leg pain and failure to return to work and that older age is probably associated with greater post-surgical impairment after a microdiscectomy. Future research should explore the association between legal representation and preoperative opioid use with persistent pain and impairment after microdiscectomy for sciatica.

L5-S1 Pseudoarthrosis Rate with ALIF Versus TLIF in Adult Spinal Deformity Surgeries: A Retrospective Analysis of 100 Patients.

OBJECTIVE: Lumbosacral pseudoarthrosis is a common complication following adult spine deformity (ASD) surgery. This study assessed the reoperation rate for L5-S1 pseudoarthrosis in the ASD population. Compared with transforaminal lumbar interbody fusions (TLIFs), we hypothesized that anterior lumbar interbody fusion (ALIF) would result in lower rates of L5-S1 pseudarthrosis. METHODS: This is a single center study with patient data retrieved from a prospective ASD database. The patients had a long-segment fusion, ALIF or TLIF at the L5-S1 level with a 2-year follow-up and were divided into 2 groups (TLIF and ALIF). The study's primary outcome was to assess the difference in the reoperation rate for clinical pseudoarthrosis between the TLIF and the ALIF groups. The secondary outcomes measured the radiological pseudoarthrosis rate and identified risks for L5-S1 pseudoarthrosis development. RESULTS: A total of 100 patients were included; 49 patients (mean age, 62.9 years; 77.5% females) were in TLIF and 51 patients (mean age, 64.4 years; 70.6% females) were in the ALIF group. Baseline characteristics were similar in both groups. Thirteen (13%) patients with L5-S1 pseudoarthrosis required reoperation. Clinical pseudoarthrosis was higher in the TLIF group than in the ALIF group (12/49 vs. 1/51; P < 0.001). Univariate analysis demonstrated a higher risk of L5-S1 pseudoarthrosis with TLIF than ALIF (risk ratio, 12.4; 95% confidence interval: 1.68-92.4; P < 0.001). Multivariate analysis revealed 4.86 times the risk of L5-S1 clinical pseudoarthrosis with TLIF than with ALIF (risk ratio, 4.86; 95% confidence interval 0.57-47; P = 0.17), but this ratio did not reach statistical significance. CONCLUSIONS: No difference in reoperation risk for L5-S1 pseudarthrosis was observed based on the method of IF. rhBMP-2 was noted as a significant predictor.