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

Severe neck pain among patients with degenerative cervical myelopathy: an observational study from the Canadian Spine Outcomes and Research Network

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. While surgical intervention is widely recognized as the primary treatment to halt disease progression and improve neurological function, its effectiveness in alleviating neck pain remains poorly understood.

PURPOSE

The aims of this study were to identify DCM patients that presented with severe neck pain and to compare their baseline characteristics and surgical outcomes to those who presented with less severe neck pain.

STUDY DESIGN/SETTING

This is a prospective, multicenter observational cohort study of the Canadian Spine Outcomes and Research Network (CSORN).

SAMPLE

Patients surgically treated for DCM between 2015 and 2022 were enrolled.

OUTCOME MEASURE

Baseline demographics, clinical/surgical details, PROs and mJOA were assessed.

METHODS

Baseline demographics, clinical/ surgical details, preoperative PROs and mJOA were compared between the patients with severe patient-rated neck pain (NP, defined as NRS-NP ≥ 8), and those with less severe NP. Between group improvements at 12 months were assessed using ANCOVA to adjust for any baseline significant differences between groups.

RESULTS

We included data from 725 DCM patients, 31.7 % (n=230) of whom presented with severe NP. Patients with severe NP were significantly more likely to be younger, smokers, unemployed, working rather than retired, unmarried, using pain medication, have a history of depression, have more comorbidities, and be physically less active (all p<.05). Baseline PROs (NRS AP and NP, NDI, SF-12 MCS and PCS and EQ5D) were significantly worse (p<.01), but mJOA scores were similar to those without severe NP. Among patients with severe NP, mean NRS-NP improved from 8.6 (SD 0.8) to 3.9 (SD 2.9, p<.01) at 12 months after surgery. Patients with severe NP were more likely to achieve MCID for neck pain in comparison to those without severe NP (74% vs. 33%, p<.01), but mean NRS-NP remained worse in this subgroup (3.9 vs. 2.6, p<.01) at 1 year after surgery. When adjusted for baseline characteristics, there were no differences between the 2 groups for the following PROs at 12 months postoperatively: NRS arm pain, NDI, SF-12 PCS, EQ5D. SF-12 MCS remained significantly worse among patients who presented with severe NP (p<.05). There was no significant difference in mJOA scores (report data) at 1 year after surgery.

CONCLUSION

Severe neck pain affects about a third of the DCM population. Most patients who presented with severe neck pain experienced substantial improvement of their neck pain after surgery. Except for mental health scores which remained worse, patients with severe neck pain experienced similar improvements in other outcome measures such as neurological function and health-related quality of life when compared to those with less severe neck pain. These findings suggest that surgical treatment not only addresses the structural causes of DCM but also provides meaningful improvements across multiple domains, underscoring its value in managing both the physical and psychosocial burdens of the disease.

Recovery Trajectories of Patient-reported Outcomes After Surgery for Degenerative Cervical Myelopathy: A Bayesian Latent Class Modeling Approach

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to identify recovery trajectory clusters after surgery for degenerative cervical myelopathy (DCM), as well as to determine clinical and imaging characteristics associated with functional recovery trajectories.

BACKGROUND

Accurate prediction of postsurgical neurological recovery for the individual patient with DCM is challenging due to varying patterns of functional recovery. Latent class Bayesian models can model individual patient patterns and identify groups of patients with similar phenotypes for personalized prognostication.

METHODS

A prospective single-center study of 70 consecutive patients with DCM undergoing elective cervical spine decompression for DCM between 2010 and 2017 was performed. Outcomes were recorded using the modified Japanese Orthopedic Association (mJOA), Neck Disability Index (NDI), and the Short Form-36 Physical Component Score (SF-36 PCS) at 3, 6, 12, and 24 months. Recovery trajectories were constructed based on unsupervised Bayesian latent class modeling. Clinical and imaging predictors of recovery trajectories were also determined.

RESULTS

Recovery after surgery for DCM showed 3 distinct recovery trajectory clusters for each outcome. The commonest recovery trajectory was sustained improvement for the mJOA (41.1%), stagnation for the NDI (60.3%), and stability for the SF-36 PCS (46.6%). Age, duration of symptoms, and baseline disability were the strongest predictors of each recovery trajectory. Degree of cord compression, neck pain, and intramedullary T2-hyperintensity were predictive of NDI and SF-36 PCS but not mJOA recovery trajectory. Sex was associated with the NDI recovery trajectory but not SF-36 PCS and mJOA recovery trajectories.

CONCLUSION

Using prospective data and a data-driven approach, we identified 3 distinct recovery trajectory clusters and associated factors for mJOA, NDI, and SF-36 PCS in the first 24 months after surgery for DCM. Our results can enhance personalized clinical prognostication and guide patient expectations at different time points after surgery for DCM.

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 nontraumatic spinal cord injury worldwide. Surgery is a common treatment for DCM; however, outcomes often vary across patients.

PURPOSE

To inform preoperative education and counseling, we performed a responder analysis to identify factors associated with treatment response.

STUDY DESIGN/SETTING

An observational cohort study was conducted utilizing prospectively collected data from the Canadian Spine Outcomes Research Network (CSORN) registry collected between 2015-2022.

PATIENT SAMPLE

We included all surgically treated DCM patients with complete 12-month follow-up and patient-reported outcomes (PROs) available at 1-year.

OUTCOME MEASURES

Treatment response was measured using the minimal clinically important difference (MCID) in PROs including the Neck Disability Index (NDI) and EuroQol-5D (EQ-5D) at 12 months postsurgery.

METHODS

A Least Absolute Shrinkage and Selection Operator (LASSO) machine learning model was used to identify significant associations between 14 preoperative patient factors and likelihood of treatment response measured by achievement of the MCID in NDI, and EQ-5D. Variable importance was measured using standardized coefficients. To test robustness of findings we trained a separate XGBOOST model, with variable importance measured using SHAP values.

RESULTS

Among the 554 DCM patients included, 229 (41.3%) and 330 (59.6%) patients responded to treatment by meeting or surpassing MCID thresholds for NDI and EQ-5D at 1-year, respectively. LASSO regression for likelihood of treatment response measured through NDI found the variable importance rank order to be baseline NDI (OR 1.06 per 1 point increase; 95% CI 1.04-1.07), then symptom duration (OR 0.65; 95% CI 0.44-0.97). For EQ-5D, the variable importance rank order was baseline EQ-5D (OR 0.16 per 0.1-point increase; 95% CI 0.03-0.78), living independently (OR 2.17; 95% CI 1.22-3.85), symptom duration (OR 0.62; 95% CI 0.40-0.97), then number of levels affected (OR 0.80 per additional level; 95% CI 0.67-0.96). A separate XGBoost model of treatment response measured through NDI, corroborated findings that patients with higher baseline NDI, and shorter symptom duration were more likely to respond to treatment, and additionally found older patients, and those with kyphosis on baseline upright X-ray were less likely to respond. Similarly, an XGBoost model for treatment response measured through EQ-5D corroborated findings that patients with higher baseline EQ-5D, shorter symptom duration, living independently, with fewer affected levels were more likely to respond to treatment, and additionally found older patients were less likely to respond.

CONCLUSIONS

Our findings suggest patients with shorter symptom duration, higher baseline patient NDI, lower EQ-5D, younger age, living independently, without kyphosis on preoperative X-ray, and fewer affected levels are more likely to respond to treatment. Timing of surgery with respect to patient symptoms is underscored as a crucial and modifiable patient factor associated with improved surgical outcomes in DCM.

1-year data on patient-reported outcome is enough after surgery for degenerative cervical myelopathy: a cohort study from the Swedish Spine register

BACKGROUND AND PURPOSE

 Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Repeated follow-ups after surgery are resource consuming. The aim was to examine whether patient-reported outcome measures (PROMs) change after the first year. The purpose of this study was to investigate whether it is necessary to obtain follow-up data from patients more than 1 year after surgery for DCM.

METHODS

 We included individuals treated surgically for DCM in the Swedish Spine registry (Swespine), with available preoperative, 1-, and 2-year PROMs, primarily the European Myelopathy Scale (EMS) and secondarily the Neck Disability Index (NDI), and the European Quality of life Visual Analogue Scale (EQ-VAS). A tertiary analysis included available 5-year data. Median, interquartile range (IQR), and Bland-Altman plots were used to compare PROM data at different follow-up time points.

RESULTS

 642 individuals had baseline, 1-, and 2-year follow-up data, of whom 347 also had 5-year data. EMS was 14 (12-16) preoperative, 15 (12-17) at the 1-year follow-up, and 15 (12-17) at the 2-year follow-up. Corresponding data for NDI was 38 (24-50), 25 (12-42), and 26 (12-42) and for EQ-VAS 50 (30-60), 60 (42-77), and 60 (40-75). Similar findings were seen in individuals who also had 5-year data. Bland-Altman plots indicated good agreement between 1- and 2-year data, and between 1- and 5-year data and were without proportional bias.

CONCLUSION

 In individuals treated for DCM no clinically meaningful change in PROMs occurred after the 1-year follow-up.

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.

Poor postoperative pain control is associated with poor long-term patient-reported outcomes after elective spine surgery: an observational cohort study

BACKGROUND CONTEXT

A significant proportion of patients experience poorly controlled surgical pain and fail to achieve satisfactory clinical improvement after spine surgery. However, a direct association between these variables has not been previously demonstrated.

PURPOSE

To investigate the association between poor postoperative pain control and patient-reported outcomes after spine surgery.

STUDY DESIGN

Ambispective cohort study.

PATIENT SAMPLE

Consecutive adult patients (≥18-years old) undergoing inpatient elective cervical or thoracolumbar spine surgery.

OUTCOME MEASURE

Poor surgical outcome was defined as failure to achieve a minimal clinically important difference (MCID) of 30% improvement on the Oswestry Disability Index or Neck Disability Index at follow-up (3-months, 1-year, and 2-years).

METHODS

Poor pain control was defined as a mean numeric rating scale score of >4 during the first 24-hours after surgery. Multivariable mixed-effects regression was used to investigate the relationship between poor pain control and changes in surgical outcomes while adjusting for known confounders. Secondarily, the Calgary Postoperative Pain After Spine Surgery (CAPPS) Score was investigated for its ability to predict poor surgical outcome.

RESULTS

Of 1294 patients, 47.8%, 37.3%, and 39.8% failed to achieve the MCID at 3-months, 1-year, and 2-years, respectively. The incidence of poor pain control was 56.9%. Multivariable analyses showed poor pain control after spine surgery was independently associated with failure to achieve the MCID (OR 2.35 [95% CI=1.59-3.46], p<.001) after adjusting for age (p=.18), female sex (p=.57), any nicotine products (p=.041), ASA physical status >2 (p<.001), ≥3 motion segment surgery (p=.008), revision surgery (p=.001), follow-up time (p<.001), and thoracolumbar surgery compared to cervical surgery (p=.004). The CAPPS score was also found to be independently predictive of poor surgical outcome.

CONCLUSION

Poor pain control in the first 24-hours after elective spine surgery was an independent risk factor for poor surgical outcome. Perioperative treatment strategies to improve postoperative pain control may lead to improved patient-reported surgical outcomes.

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.

Racial and Socioeconomic Disparities in Laminoplasty Versus Laminectomy With Fusion in Patients With Cervical Spondylosis

STUDY DESIGN

A retrospective cohort study using prospectively collected data.

OBJECTIVE

The aim of this study was to investigate preoperative differences in racial and socioeconomic factors in patients undergoing laminoplasty (LP) versus laminectomy and fusion (LF) for degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

DCM is prevalent in the United States, requiring surgical intervention to prevent neurological degeneration. While LF is utilized more frequently, LP is an emerging alternative. Previous studies have demonstrated similar neurological outcomes for both procedures. However, treatment selection is primarily at the discretion of the surgeon and may be influenced by social determinants of health that impact surgical outcomes.

MATERIALS AND METHODS

The Quality Outcome Database (QOD), a national spine registry, was queried for adult patients who underwent either LP or LF for the management of DCM. Covariates associated with socioeconomic status, pain and disability, and demographic and medical history were collected. Multivariate logistic regression was performed to assess patient factors associated with undergoing LP versus LF.

RESULTS

Of 1673 DCM patients, 157 (9.4%) underwent LP and 1516 (90.6%) underwent LF. A significantly greater proportion of LP patients had private insurance (P<0.001), a greater than high school level education (P<0.001), were employed (P<0.001), and underwent primary surgery (P<0.001). LP patients reported significantly lower baseline neck/arm pain and Neck Disability Index (P<0.001). In the multivariate regression model, lower baseline neck pain [odds ratio (OR)=0.915, P=0.001], identifying as non-Caucasian (OR=2.082, P<0.032), being employed (OR=1.592, P=0.023), and having a greater than high school level education (OR=1.845, P<0.001) were associated with undergoing LP rather than LF.

CONCLUSIONS

In DCM patients undergoing surgery, factors associated with patients undergoing LP versus LF included lower baseline neck pain, non-Caucasian race, higher education, and employment. While symptomatology may influence the decision to choose LP over LF, there may also be socioeconomic factors at play. The trend of more educated and employed patients undergoing LP warrants further investigation.

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.

Subclinical respiratory dysfunction and impaired ventilatory adaptation in degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is a debilitating neurological condition characterized by chronic compression of the cervical spinal cord leading to impaired upper and lower limb function. Despite damage to areas of the cervical spinal cord that house the respiratory network, respiratory dysfunction is not a common symptom of DCM. However, DCM may be associated with respiratory dysfunction, and this can affect the ventilatory response to respiratory challenges during emergence from anesthesia, exercise, or pulmonary disease. Surgical spinal cord decompression, which is the primary treatment for DCM, leads to improved sensorimotor function in DCM; yet its impact on respiratory function is unknown. Here, using a clinically relevant model of DCM, we evaluate respiratory function during disease progression and assess adaptive ventilation to hypercapnic challenge before and after surgical intervention. We show that despite significant and progressive forelimb and locomotor deficits, there was no significant decline in eupneic ventilation from the early to late phases of spinal cord compression. Additionally, for the first time, we demonstrate that despite normal ventilation under resting conditions, DCM impairs acute adaptive ventilatory ability in response to hypercapnia. Remarkably, akin to DCM patients, surgical decompression treatment improved sensorimotor function in a subset of mice. In contrast, none of the mice that underwent surgical decompression recovered their ability to respond to hypercapnic ventilatory challenge. These findings underscore the impact of chronic spinal cord compression on respiratory function, highlighting the challenges associated with ventilatory response to respiratory challenges in individuals with DCM. This research highlights the impact of cervical spinal cord compression on respiratory dysfunction in DCM, as well as the persistence of adaptive ventilatory dysfunction after surgical spinal cord decompression. These results indicate the need for additional interventions to enhance recovery of respiratory function after surgery for DCM.

Correlation between "Snake-Eyes" Sign and Role of Surgery with a Focus on Postoperative Outcome: A Systematic Review

(1) Background: The "snake-eyes" sign represents a unique finding characterized by bilateral hyperintense symmetric, circular, or ovoid foci on T2-weighted MRI sequences in the anterior horn cells of the spinal cord. There are conflicting opinions as some authors affirm that it does not affect the prognosis of cervical myelopathy while other papers emphasize the opposite, stating how the "snake-eyes" sign constitutes an irreversible lesion and a predictor of poor prognosis. This systematic review evaluates the correlation between the "snake-eyes" sign and the prognosis of cervical myelopathy after surgery including anterior and/or posterior approaches; (2) Methods: A systematic literature review was conducted following the PRISMA statement and a total of seven papers were included; (3) Results: A total of 419 patients were evaluated, with a mean age of 55.72 ± 14.38 years. After surgery, 26.01% of patients experienced a significant clinical improvement, while in 61.81%, there was no significant improvement. In particular, 144 of 196 patients (73.5%) treated through an anterior approach and 114 of 223 (51.1%) that underwent a posterior approach, did not present a significant improvement. Furthermore, in 12.17% of patients, the postoperative outcome was not reported, leading to a high risk of bias in the assessment of the prognostic significance of the "snake-eyes" appearance; (4) Conclusions: The "snake-eyes" sign is usually considered as an unfavorable predictive marker for myelopathic surgical patients, but the pathophysiology is still unclear, and the results have not yet reached unified levels of evidence.