Who Gets Better After Surgery for Degenerative Cervical Myelopathy? A Responder Analysis from the Multicenter Canadian Spine Outcomes and Research Network.

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is the most common cause of acquired non-traumatic 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 (EQ-5D) at 12 months post-surgery. METHODS: A Least Absolute Shrinkage and Selection Operator (LASSO) machine learning model was used to identify significant associations between 14 pre-operative 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 pre-operative 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.

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.

Focal compression of the cervical spinal cord alone does not indicate high risk of neurological deterioration in patients with a diagnosis of mild degenerative cervical myelopathy.

Degenerative Cervical Myelopathy (DCM) is the functional derangement of the spinal cord resulting from vertebral column spondylotic degeneration. Typical neurological symptoms of DCM include gait imbalance, hand/arm numbness, and upper extremity dexterity loss. Greater spinal cord compression is believed to lead to a higher rate of neurological deterioration, although clinical experience suggests a more complex mechanism involving spinal canal diameter (SCD). In this study, we utilized machine learning clustering to understand the relationship between SCD and different patterns of cord compression (i.e. compression at one disc level, two disc levels, etc.) to identify patient groups at risk of neurological deterioration. 124 MRI scans from 51 non-operative DCM patients were assessed through manual scoring of cord compression and SCD measurements. Dimensionality reduction techniques and k-means clustering established patient groups that were then defined with their unique risk criteria. We found that the compression pattern is unimportant at SCD extremes (≤14.5 mm or > 15.75 mm). Otherwise, severe spinal cord compression at two disc levels increases deterioration likelihood. Notably, if SCD is normal and cord compression is not severe at multiple levels, deterioration likelihood is relatively reduced, even if the spinal cord is experiencing compression. We elucidated five patient groups with their associated risks of deterioration, according to both SCD range and cord compression pattern. Overall, SCD and focal cord compression alone do not reliably predict an increased risk of neurological deterioration. Instead, the specific combination of narrow SCD with multi-level focal cord compression increases the likelihood of neurological deterioration in mild DCM patients.

Advanced MRI metrics improve the prediction of baseline disease severity for individuals with degenerative cervical myelopathy.

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is the most common form of atraumatic spinal cord injury globally. Degeneration of spinal discs, bony osteophyte growth and ligament pathology results in physical compression of the spinal cord contributing to damage of white matter tracts and grey matter cellular populations. This results in an insidious neurological and functional decline in patients which can lead to paralysis. Magnetic resonance imaging (MRI) confirms the diagnosis of DCM and is a prerequisite to surgical intervention, the only known treatment for this disorder. Unfortunately, there is a weak correlation between features of current commonly acquired MRI scans ("community MRI, cMRI") and the degree of disability experienced by a patient. PURPOSE: This study examines the predictive ability of current MRI sequences relative to "advanced MRI" (aMRI) metrics designed to detect evidence of spinal cord injury secondary to degenerative myelopathy. We hypothesize that the utilization of higher fidelity aMRI scans will increase the effectiveness of machine learning models predicting DCM severity and may ultimately lead to a more efficient protocol for identifying patients in need of surgical intervention. STUDY DESIGN/SETTING: Single institution analysis of imaging registry of patients with DCM. PATIENT SAMPLE: A total of 296 patients in the cMRI group and 228 patients in the aMRI group. OUTCOME MEASURES: Physiologic measures: accuracy of machine learning algorithms to detect severity of DCM assessed clinically based on the modified Japanese Orthopedic Association (mJOA) scale. METHODS: Patients enrolled in the Canadian Spine Outcomes Research Network registry with DCM were screened and 296 cervical spine MRIs acquired in cMRI were compared with 228 aMRI acquisitions. aMRI acquisitions consisted of diffusion tensor imaging, magnetization transfer, T2-weighted, and T2*-weighted images. The cMRI group consisted of only T2-weighted MRI scans. Various machine learning models were applied to both MRI groups to assess accuracy of prediction of baseline disease severity assessed clinically using the mJOA scale for cervical myelopathy. RESULTS: Through the utilization of Random Forest Classifiers, disease severity was predicted with 41.8% accuracy in cMRI scans and 73.3% in the aMRI scans. Across different predictive model variations tested, the aMRI scans consistently produced higher prediction accuracies compared to the cMRI counterparts. CONCLUSIONS: aMRI metrics perform better in machine learning models at predicting disease severity of patients with DCM. Continued work is needed to refine these models and address DCM severity class imbalance concerns, ultimately improving model confidence for clinical implementation.

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.

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.

Development of the cervical myelopathy severity index: a new patient reported outcome measure to quantify impairments and functional limitations.

BACKGROUND CONTEXT: Existing degenerative cervical myelopathy (DCM) severity scales have significant shortcomings, creating a strong impetus for the development of a practical measurement tool with sound psychometric properties. PURPOSE: This work reports the item generation and reduction of the Cervical Myelopathy Severity Index (CMSI), a new DCM patient-reported outcome measure of symptoms and functional limitations. DESIGN: Prospective observational study. PATIENT SAMPLE: Adult DCM patients belonging to one of three distinct treatment groups: (1) observation cohort, (2) preoperative surgical cohort, (3) 6 to 12 months postoperative cohort. OUTCOME MEASURES: Patient-reported outcome measure of symptoms and functional limitations. METHODS: Item generation was performed using semi-structured patient focus groups emphasizing symptoms experienced and functional limitations. Readability was assessed through think-aloud patient interviews. Item reduction involved surveys of DCM patients with a spectrum of disease severity and board-certified spine surgeons experienced in the treatment of DCM. A priori criteria for item removal included: patient median importance/severity <2 (of 4), 30% or more no severity (response of zero), item severity correlations ≤ 0.80 (Spearman), item severity reliability (weighted kappa <0.60) based on a 2-week interval and clinician median importance <2 with retention of items with very high clinical importance. RESULTS: There were 42 items generated from a combination of specialist input and patient focus groups. Items captured sensorimotor symptoms and limitations related to upper and lower extremities as well as sphincter dysfunction. Ninety-eight patients (43, 30, 25 observation, pre- and postsurgery respectively) and 51 surgeons completed the assessment. Twenty-three items remained after application of median importance and severity thresholds and weighted kappa cutoffs. After elimination of highly correlated (>0.80) items and combining two similar items, the final CMSI questionnaire list included 14 items. CONCLUSIONS: The CMSI is a new DCM patient-reported clinical measurement tool developed using patient and clinician input to inform item generation and reduction. Future work will evaluate the reliability, validity, and responsiveness of the CMSI in relation to existing myelopathy measurement indices.

Does Ending a Posterior Construct Proximally at C2 Versus C3 Impact Patient Reported Outcomes in Degenerative Cervical Myelopathy Patients up to 24 months After the Surgery?

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The primary objective was to evaluate the impact of the upper instrumented level (UIV) being at C2 vs C3 in posterior cervical construct on patient reported outcomes (PROs) up to 24 months after surgery for cervical degenerative myelopathy (DCM). Secondary objectives were to compare operative time, intra-operative blood loss (IOBL), length of stay (LOS), adverse events (AEs) and re-operation. METHODOLOGY: Patients who underwent a posterior cervical instrumented fusion (3 and + levels) with a C2 or C3 UIV, with 24 months follow-up were analyzed. PROs (NDI, EQ5D, SF-12 PCS/MCS, NRS arm/neck pain) were compared using ANCOVA. Operative duration, IOBL, AEs, and re-operation were compared. Subgroup analysis was performed on patient presenting with pre-operative malalignment (cervical sagittal vertical axis ≥40 mm and/or T1slope- cervical lordosis >15°). RESULTS: 173 patients were included, of which 41 (24%) had a C2 UIV and 132 (76%) a C3 UIV. There was no statistically significant difference between the groups for the changes in PROs up to 24 months. Subgroup analysis of patients with pre-operative malalignment showed a trend towards greater improvement in the NDI at 12 months with a C2 UIV (P = .054). Operative time, IOBL and peri-operative AEs were more in C2 group (P < .05). There was no significant difference in LOS and re-operation (P > .05). CONCLUSION: In this observational study, up to 24 months after surgery for posterior cervical fusion in DCM greater than 3 levels, PROs appear to evolve similarly.

Deterioration After Surgery for Degenerative Cervical Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

STUDY DESIGN: A Prospective cohort study. OBJECTIVE: To investigate the incidence, etiology, and outcomes of patients who experience neurological deterioration after surgery for Degenerative Cervical Myelopathy (DCM). SUMMARY OF BACKGROUND DATA: Postoperative neurological deterioration is one of the most undesirable complications that can occur after surgery for DCM. METHODS: We analyzed data from the Canadian Spine Outcomes and Research Network DCM prospective cohort study. We defined postoperative neurological deterioration as any decrease in modified Japanese Orthopaedic Association (mJOA) score by at least one point from baseline to three months after surgery. Adverse events were collected using the Spinal Adverse Events Severity protocol. Secondary outcomes included patient-reported pain, disability, and health-related quality of life. RESULTS: Among a study cohort of 428 patients, 50 (12%) deteriorated by at least one mJOA point after surgery for DCM (21 by one point, 15 by two points, and 14 by three points or more). Significant risk factors included older age, female sex, and milder disease. Among those who deteriorated, 13 experienced contributing intraoperative or postoperative adverse events, six had alternative non-DCM diagnoses, and 31 did not have an identifiable reason for deterioration. Patients who deteriorated had significantly lower mJOA scores at one year after surgery [13.5 (SD 2.7) vs. 15.2 (SD 2.2), P <0.01 and those with larger deteriorations were less likely to recover their mJOA to at least their preoperative baseline, but most secondary measures of pain, disability, and health-related quality of life were unaffected. CONCLUSIONS: The incidence of deterioration of mJOA scores after surgery for DCM was approximately one in 10, but some deteriorations were unrelated to actual spinal cord impairment and most secondary outcomes were unaffected. These findings can inform patient and surgeon expectations during shared decision-making, and they demonstrate that the interpretation of mJOA scores without clinical context can sometimes be misleading.

Timing of Recovery After Surgery for Patients With Degenerative Cervical Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

BACKGROUND: The time course over which postoperative neurological recovery occurs after surgery for degenerative cervical myelopathy occurs is poorly understood. OBJECTIVE: To determine the time point at which patients experience significant neurological improvement. METHODS: We reviewed data from an ongoing prospective multicenter cohort study. We measured neurological function at 3 months, 1 year, and 2 years after surgery using the modified Japanese Orthopedic Association (mJOA) scale. We implemented minimal clinical important differences (MCIDs) to guide interpretation of mJOA scores, and we used 1-way analysis of variance to compare changes between follow-up intervals. RESULTS: Among 330 patients, the mean overall mJOA improved from 12.9 (SD 2.6) to 14.6 (SD 2.4) at 3 months, 14.7 (SD 2.4) at 1 year, and 14.8 (SD 2.5) at 2 years. The difference in means was statistically significant (P < .01) at the interval from baseline to 3 months postoperatively, but not from 3 months to 1 year or 1 year to 2 years. The MCID was reached by 161 patients at 3 months, 32 more at 1 year, and 15 more at 2 years, with a statistically significant difference only at 3 months. Patients with moderate or severe disease reached the MCID more frequently than those with mild disease. CONCLUSION: Among patients who underwent surgery for degenerative cervical myelopathy, most significant neurological improvement occurred by 3 months after surgery. These findings will facilitate valid discussions about postoperative expectations during shared clinical decision making between patients and their surgeons.

Does extending a posterior cervical fusion construct into the upper thoracic spine impact patient-reported outcomes as long as 2 years after surgery in patients with degenerative cervical myelopathy?

OBJECTIVE: In multilevel posterior cervical instrumented fusion, extension of fusion across the cervicothoracic junction (CTJ) at T1 or T2 has been associated with decreased rates of reoperation and pseudarthrosis but with longer surgical time and increased blood loss. The impact on patient-reported outcomes (PROs) remains unclear. The primary objective was to determine whether extension of fusion through the CTJ influenced PROs at 3, 12, and 24 months after surgery. The secondary objective was to compare the number of patients who reached the minimal clinically important differences (MCIDs) for the PROs, modified Japanese Orthopaedic Association (mJOA) score, operative time, intraoperative blood loss, length of stay, discharge disposition, adverse events (AEs), reoperation within 24 months of surgery, and patient satisfaction. METHODS: This was a retrospective observational cohort study of prospectively collected multicenter data of patients with degenerative cervical myelopathy. Patients who underwent posterior instrumented fusion of 4 levels or greater (between C2 and T2) between January 2015 and October 2020 and received 24 months of follow-up were included. PROs (scores on the Neck Disability Index [NDI], EQ-5D, physical component summary and mental component summary of SF-12, and numeric rating scale for arm and neck pain) and mJOA scores were compared using ANCOVA and adjusted for baseline differences. Patient demographic characteristics, comorbidities, and surgical details were abstracted. The proportions of patients who reached the MCIDs for these outcomes were compared with the chi-square test. Operative duration, intraoperative blood loss, AEs, reoperation, discharge disposition, length of stay, and satisfaction was compared by using the chi-square test for categorical variables and the independent-samples t-test for continuous variables. RESULTS: A total of 198 patients were included in this study (101 patients with fusion not crossing the CTJ and 97 with fusion crossing the CTJ). Patients with a construct extending through the CTJ were more likely to be female and have worse baseline NDI scores (p > 0.05). When adjusted for baseline differences, there were no statistically significant differences between the two groups in terms of the PROs and mJOA scores at 3, 12, and 24 months. Surgical duration was longer (p < 0.001) and intraoperative blood loss was greater in the group with fusion extending to the upper thoracic spine (p = 0.013). There were no significant differences between groups in terms of AEs (p > 0.05). Fusion with a construct crossing the CTJ was associated with reoperation (p = 0.04). Satisfaction with surgery was not significantly different between groups. The proportions of patients who reached the MCIDs for the PROs were not statistically different at any time point. CONCLUSIONS: There were no statistically significant differences in PROs between patients with a posterior construct extending to the upper thoracic spine and those without such extension for as long as 24 months after surgery. The AE profiles were not significantly different, but longer surgical time and increased blood loss were associated with constructs extending across the CTJ.

Predictors of home discharge after scheduled surgery for degenerative cervical myelopathy.

OBJECTIVE: Degenerative cervical myelopathy (DCM) is an important public health issue. Surgery is the mainstay of treatment for moderate and severe DCM. Delayed discharge of patients after DCM surgery is associated with increased healthcare costs. There is a paucity of data regarding predictive factors for discharge destination after scheduled surgery for patients with DCM. The purpose of this study was to identify factors predictive of home versus nonhome discharge after DCM surgery. METHODS: Patients undergoing scheduled DCM surgery who had been enrolled in a prospective DCM substudy of the Canadian Spine Outcomes and Research Network registry between January 2015 and October 2020 were included in this retrospective analysis. Patient data were evaluated to identify potential factors predictive of home discharge after surgery. Logistic regression was used to identify independent factors predictive of home discharge. A multivariable model was then used as a final model. RESULTS: Overall, 639 patients were included in the initial analysis, 543 (85%) of whom were discharged home. The mean age of the entire cohort was 60 years (SD 11.8 years), with a BMI of 28.9 (SD 5.7). Overall, 61.7% of the patients were female. The mean length of stay was 2.72 days (SD 1.7 days). The final internally validated bootstrapped multivariable model revealed that younger age, higher 9-Item Patient Health Questionnaire score, lower Neck Disability Index scores, fewer operated levels, mJOA scores indicating mild disease, anterior cervical discectomy and fusion procedure, and no perioperative adverse effects were predictive of home discharge. CONCLUSIONS: Younger age, less neck-related disability, fewer operated levels, more significant depression, less severe myelopathy, anterior cervical discectomy and fusion procedure, and no perioperative adverse effects are predictive of home discharge after surgery for DCM. These factors can help to guide clinical decision-making and optimize postoperative care pathways.

Cervical Sagittal Alignment in Patients with Cervical Spondylotic Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Among patients with CSM, we aimed to evaluate the extent to which: (1) Preoperative cervical sagittal alignment is associated with health-related quality of life, function, and symptoms; (2) Surgery leads to changes in cervical sagittal alignment; and (3) Postoperative cervical sagittal alignment is associated with health-related quality of life, function, and symptoms at 12 months of follow-up. SUMMARY OF BACKGROUND DATA: The importance of maintaining or improving cervical sagittal alignment in the surgical management of patients with CSM has not been established. METHODS: We measured C2-C7 Cobb angle, T1 slope, and C2-C7 cervical sagittal vertical axis (cSVA). We tested for associations with Neck Disability Index, Pain Scales for neck and arm pain, EuroQol 5D, Short Form 12 Physical and Mental Component Summaries, and modified Japanese Orthopaedic Association scores. We adjusted for potential confounders using multiple linear regression, and we performed various prespecified subgroup (cSVA > 40 mm, surgical approach) and sensitivity analyses. RESULTS: Among 250 patients, adjusted analyses yielded significant inverse associations prior to surgery between each of cSVA and T1 slope with SF12 Physical Component Summaries (T1 slope: -0.14, 95% CI -0.26 to -0.01, P = 0.03; C2-C7 cSVA: -0.13, 95% CI --0.21 to -0.05 P < 0.01). Surgery was associated with a small but statistically significant increase in cSVA across the cohort (+5.8 mm [SD 11.7], P < 0.01) but no change in Cobb angle or T1 slope. At 12-months after surgery, there were no significant associations between alignment parameters or change in alignment and any measures of health-related quality of life, function, or symptoms. Results were consistent across subgroup and sensitivity analyses. CONCLUSION: Increased cSVA and T1 slope were associated with inferior health-related quality of life at presentation among patients with CSM, but no significant associations were observed following surgical treatment.Level of Evidence: 3.

Factors Associated With Return to Work After Surgery for Degenerative Cervical Spondylotic Myelopathy: Cohort Analysis From the Canadian Spine Outcomes and Research Network.

STUDY DESIGN: Retrosepctive analysis of prospectively collected data from the multicentre Canadian Surgical Spine Registry (CSORN). OBJECTIVE: Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in North America. Few studies have evaluated return to work (RTW) rates after DCM surgery. Our goals were to determine rates and factors associated with postoperative RTW in surgically managed patients with DCM. METHODS: Data was derived from the prospective, multicenter Canadian Spine Outcomes and Research Network (CSORN). From this cohort, we included all nonretired patients with at least 1-year follow-up. The RTW rate was defined as the proportion of patients with active employment at 1 year from the time of surgery. Unadjusted and adjusted analyses were used to identify patient characteristics, disease, and treatment variables associated with RTW. RESULTS: Of 213 surgically treated DCM patients, 126 met eligibility, with 49% working and 51% not working in the immediate period before surgery; 102 had 12-month follow-up data. In both the unadjusted and the adjusted analyses working preoperatively and an anterior approach were associated with a higher postoperative RTW (P < .05), there were no significant differences between the postoperative employment groups with respect to age, gender, preoperative mJOA (modified Japanese Orthopaedic Association) score, and duration of symptoms (P > .05). Active preoperative employment (odds ratio = 15.4, 95% confidence interval = 4.5, 52.4) and anterior surgical procedures (odds ratio = 4.7, 95% confidence interval = 1.2, 19.6) were associated with greater odds of RTW at 1 year. CONCLUSIONS: The majority of nonretired patients undergoing surgery for DCM had returned to work 12 months after surgery; active preoperative employment and anterior surgical approach were associated with RTW in this analysis.

Spinal Cord Signal Change on Magnetic Resonance Imaging May Predict Worse Clinical In- and Outpatient Outcomes in Patients with Spinal Cord Injury: A Prospective Multicenter Study in 459 Patients.

Prognostic factors for clinical outcome after spinal cord (SC) injury (SCI) are limited but important in patient management and education. There is a lack of evidence regarding magnetic resonance imaging (MRI) and clinical outcomes in SCI patients. Therefore, we aimed to investigate whether baseline MRI features predicted the clinical course of the disease. This study is an ancillary to the prospective North American Clinical Trials Network (NACTN) registry. Patients were enrolled from 2005-2017. MRI within 72 h of injury and a minimum follow-up of one year were available for 459 patients. Patients with American Spinal Injury Association impairment scale (AIS) E were excluded. Patients were grouped into those with (n = 354) versus without (n = 105) SC signal change on MRI T2-weighted images. Logistic regression analysis adjusted for commonly known a priori confounders (age and baseline AIS). Main outcomes and measures: The primary outcome was any adverse event. Secondary outcomes were AIS at the baseline and final follow-up, length of hospital stay (LOS), and mortality. A regression model adjusted for age and baseline AIS. Patients with intrinsic SC signal change were younger (46.0 (interquartile range (IQR) 29.0 vs. 50.0 (IQR 20.5) years, p = 0.039). There were no significant differences in the other baseline variables, gender, body mass index, comorbidities, and injury location. There were more adverse events in patients with SC signal change (230 (65.0%) vs. 47 (44.8%), p < 0.001; odds ratio (OR) = 2.09 (95% confidence interval (CI) 1.31-3.35), p = 0.002). The most common adverse event was cardiopulmonary (186 (40.5%)). Patients were less likely to be in the AIS D category with SC signal change at baseline (OR = 0.45 (95% CI 0.28-0.72), p = 0.001) and in the AIS D or E category at the final follow-up (OR = 0.36 (95% CI 0.16-0.82), p = 0.015). The length of stay was longer in patients with SC signal change (13.0 (IQR 17.0) vs. 11.0 (IQR 14.0), p = 0.049). There was no difference between the groups in mortality (11 (3.2%) vs. 4 (3.9%)). MRI SC signal change may predict adverse events and overall LOS in the SCI population. If present, patients are more likely to have a worse baseline clinical presentation (i.e., AIS) and in- or outpatient clinical outcome after one year. Patients with SC signal change may benefit from earlier, more aggressive treatment strategies and need to be educated about an unfavorable prognosis.

Effectiveness of Surgical Decompression in Patients With Degenerative Cervical Myelopathy: Results of the Canadian Prospective Multicenter Study.

BACKGROUND: Conflicting evidence exists regarding the effectiveness of surgery for degenerative cervical myelopathy (DCM), particularly in mild DCM. OBJECTIVE: To prospectively evaluate the impact of surgery on patient-reported outcomes in patients with mild (modified Japanese Orthopaedic Association [mJOA] ≥ 15), moderate (mJOA 12-14), and severe (mJOA < 12) DCM. METHODS: Prospective, multicenter cohort study of patients with DCM who underwent surgery between 2015 and 2019 and completed 1-yr follow-up. Outcome measures (mJOA, Neck Disability Index [NDI], EuroQol-5D [EQ-5D], Short Form [SF-12] Physical Component Score [PCS]/Mental Component Score [MCS], numeric rating scale [NRS] neck, and arm pain) were assessed at 3 and 12 mo postoperatively and compared to baseline, stratified by DCM severity. Changes in outcome measures that were statistically significant (P < .05) and met their respective minimum clinically important differences (MCIDs) were deemed clinically meaningful. Responder analysis was performed to compare the proportion of patients between DCM severity groups who met the MCID for each outcome measure. RESULTS: The cohort comprised 391 patients: 110 mild, 163 moderate, and 118 severe. At 12 mo after surgery, severe DCM patients experienced significant improvements in all outcome measures; moderate DCM patients improved in mJOA, NDI, EQ-5D, and PCS; mild DCM patients improved in EQ-5D and PCS. There was no significant difference between severity groups in the proportion of patients reaching MCID at 12 mo after surgery for any outcome measure, except NDI. CONCLUSION: At 12 mo after surgery, patients with mild, moderate, and severe DCM all demonstrated improved outcomes. Severe DCM patients experienced the greatest breadth of improvement, but the proportion of patients in each severity group achieving clinically meaningful changes did not differ significantly across most outcome measures.

Spinal Cord Morphology in Degenerative Cervical Myelopathy Patients; Assessing Key Morphological Characteristics Using Machine Vision Tools.

Despite Degenerative Cervical Myelopathy (DCM) being the most common form of spinal cord injury, effective methods to evaluate patients for its presence and severity are only starting to appear. Evaluation of patient images, while fast, is often unreliable; the pathology of DCM is complex, and clinicians often have difficulty predicting patient prognosis. Automated tools, such as the Spinal Cord Toolbox (SCT), show promise, but remain in the early stages of development. To evaluate the current state of an SCT automated process, we applied it to MR imaging records from 328 DCM patients, using the modified Japanese Orthopedic Associate scale as a measure of DCM severity. We found that the metrics extracted from these automated methods are insufficient to reliably predict disease severity. Such automated processes showed potential, however, by highlighting trends and barriers which future analyses could, with time, overcome. This, paired with findings from other studies with similar processes, suggests that additional non-imaging metrics could be added to achieve diagnostically relevant predictions. Although modeling techniques such as these are still in their infancy, future models of DCM severity could greatly improve automated clinical diagnosis, communications with patients, and patient outcomes.

Clinical predictors of achieving the minimal clinically important difference after surgery for cervical spondylotic myelopathy: an external validation study from the Canadian Spine Outcomes and Research Network.

OBJECTIVE: Recently identified prognostic variables among patients undergoing surgery for cervical spondylotic myelopathy (CSM) are limited to two large international data sets. To optimally inform shared clinical decision-making, the authors evaluated which preoperative clinical factors are significantly associated with improvement on the modified Japanese Orthopaedic Association (mJOA) scale by at least the minimum clinically important difference (MCID) 12 months after surgery, among patients from the Canadian Spine Outcomes and Research Network (CSORN). METHODS: The authors performed an observational cohort study with data that were prospectively collected from CSM patients at 7 centers between 2015 and 2017. Candidate variables were tested using univariable and multiple binomial logistic regression, and multiple sensitivity analyses were performed to test assumptions about the nature of the statistical models. Validated mJOA MCIDs were implemented that varied according to baseline CSM severity. RESULTS: Among 205 patients with CSM, there were 64 (31%) classified as mild, 86 (42%) as moderate, and 55 (27%) as severe. Overall, 52% of patients achieved MCID and the mean change in mJOA score at 12 months after surgery was 1.7 ± 2.6 points (p < 0.01), but the subgroup of patients with mild CSM did not significantly improve (mean change 0.1 ± 1.9 points, p = 0.8). Univariate analyses failed to identify significant associations between achieving MCID and sex, BMI, living status, education, smoking, disability claims, or number of comorbidities. After adjustment for potential confounders, the odds of achieving MCID were significantly reduced with older age (OR 0.7 per decade, 95% CI 0.5-0.9, p < 0.01) and higher baseline mJOA score (OR 0.8 per point, 95% CI 0.7-0.9, p < 0.01). The effects of symptom duration (OR 1.0 per additional month, 95% CI 0.9-1.0, p = 0.2) and smoking (OR 0.4, 95% CI 0.2-1.0, p = 0.06) were not statistically significant. CONCLUSIONS: Surgery is effective at halting the progression of functional decline with CSM, and approximately half of all patients achieve the MCID. Data from the CSORN confirmed that older age is independently associated with poorer outcomes, but novel findings include that patients with milder CSM did not experience meaningful improvement, and that symptom duration and smoking were not important. These findings support a nuanced approach to shared decision-making that acknowledges some prognostic uncertainty when weighing the various risks, benefits, and alternatives to surgical treatment.

The impact of machine learning on patient care: A systematic review.

BACKGROUND: Despite the expanding use of machine learning (ML) in fields such as finance and marketing, its application in the daily practice of clinical medicine is almost non-existent. In this systematic review, we describe the various areas within clinical medicine that have applied the use of ML to improve patient care. METHODS: A systematic review was performed in accordance with the PRISMA guidelines using Medline(R), EBM Reviews, Embase, Psych Info, and Cochrane Databases, focusing on human studies that used ML to directly address a clinical problem. Included studies were published from January 1, 2000 to May 1, 2018 and provided metrics on the performance of the utilized ML tool. RESULTS: A total of 1909 unique publications were reviewed, with 378 retrospective articles and 8 prospective articles meeting inclusion criteria. Retrospective publications were found to be increasing in frequency, with 61 % of articles published within the last 4 years. Prospective articles comprised only 2 % of the articles meeting our inclusion criteria. These studies utilized a prospective cohort design with an average sample size of 531. CONCLUSION: The majority of literature describing the use of ML in clinical medicine is retrospective in nature and often outlines proof-of-concept approaches to impact patient care. We postulate that identifying and overcoming key translational barriers, including real-time access to clinical data, data security, physician approval of "black box" generated results, and performance evaluation will allow for a fundamental shift in medical practice, where specialized tools will aid the healthcare team in providing better patient care.