Significant Predictors of Outcome Following Surgery for the Treatment of Degenerative Cervical Myelopathy

Assessment of Surgical Outcomes in Patients with Degenerative Cervical Myelopathy Using the 25-Question Geriatric Locomotive Function Scale: A Longitudinal Observational Study

Introduction

Locomotive syndrome caused by degenerative musculoskeletal diseases is reported to improve with surgical treatment. However, it is unclear whether surgical treatment is effective for the locomotive syndrome developing in patients with degenerative cervical myelopathy (DCM). Thus, this study primarily aimed to longitudinally assess the change in locomotive syndrome stage before and after cervical spinal surgery for patients with DCM using the 25-question geriatric locomotive function scale (GLFS-25). A secondary objective was to identify factors associated with the postoperative improvement in the locomotive syndrome stage.

Methods

We retrospectively reviewed clinical data of patients undergoing cervical spine surgery at our institution from April 2020 to May 2022 who had answered the Japanese Orthopaedic Association Cervical Myelopathy Assessment Questionnaire, visual analog scale, and GLFS-25 preoperatively and at 6 months and 1 year postoperatively. We collected demographic data, medical history, preoperative radiographic parameters, presence or absence of posterior longitudinal ligament ossification, and surgical data.

Results

We enrolled 115 patients (78 men and 37 women) in the present study. Preoperatively, using the GLFS-25, 73.9% of patients had stage 3, 10.4% had stage 2, 9.6% had stage 1, 6.1% had no locomotive syndrome. The stage distribution of locomotive syndrome improved significantly at 6-months and 1-year postoperatively. The multivariable Poisson regression analysis revealed that better preoperative lower extremity function (relative risk: 3.0; 95% confidence interval: 1.01-8.8) was significantly associated with postoperative improvement in the locomotive syndrome stage.

Conclusions

This is the first study to longitudinally assess the locomotive syndrome stage in patients with DCM using GLFS-25. Our results indicated that patients with DCM experienced significant improvement in the locomotive syndrome stage following cervical spine surgery. Particularly, the preoperative lower extremity function was significant in postoperative improvement in the locomotive syndrome stage.

Mapping the Degenerative Cervical Myelopathy Research Landscape: Topic Modeling of the Literature

STUDY DESIGN

Topic modeling of literature.

OBJECTIVES

Our study has 2 goals: (i) to clarify key themes in degenerative cervical myelopathy (DCM) research, and (ii) to evaluate the current trends in the popularity or decline of these topics. Additionally, we aim to highlight the potential of natural language processing (NLP) in facilitating research syntheses.

METHODS

Documents were retrieved from Scopus, preprocessed, and modeled using BERTopic, an NLP-based topic modeling method. We specified a minimum topic size of 25 documents and 50 words per topic. After the models were trained, they generated a list of topics and corresponding representative documents. We utilized linear regression models to examine trends within the identified topics. In this context, topics exhibiting increasing linear slopes were categorized as "hot topics," while those with decreasing slopes were categorized as "cold topics".

RESULTS

Our analysis retrieved 3510 documents that were classified into 21 different topics. The 3 most frequently occurring topics were "OPLL" (ossification of the posterior longitudinal ligament), "Anterior Fusion," and "Surgical Outcomes." Trend analysis revealed the hottest topics of the decade to be "Animal Models," "DCM in the Elderly," and "Posterior Decompression" while "Morphometric Analyses," "Questionnaires," and "MEP and SSEP" were identified as being the coldest topics.

CONCLUSIONS

Our NLP methodology conducted a thorough and detailed analysis of DCM research, uncovering valuable insights into research trends that were otherwise difficult to discern using traditional techniques. The results provide valuable guidance for future research directions, policy considerations, and identification of emerging trends.

Scoping Review with Topic Modeling on the Diagnostic Criteria for Degenerative Cervical Myelopathy

STUDY DESIGN

This study is a scoping review.

OBJECTIVE

There is a broad variability in the definition of degenerative cervical myelopathy (DCM) and no standardized set of diagnostic criteria to date.

METHODS

We interrogated the Myelopathy.org database, a hand-indexed database of primary clinical studies conducted exclusively on DCM in humans between 2005-2021. The DCM inclusion criteria used in these studies were inputted into 3 topic modeling algorithms: Hierarchical Dirichlet Process (HDP), Latent Dirichlet Allocation (LDA), and BERtopic. The emerging topics were subjected to manual labeling and interpretation.

RESULTS

Of 1676 reports, 120 papers (7.16%) had well-defined inclusion criteria and were subjected to topic modeling. Four topics emerged from the HDP model: disturbance from extremity weakness and motor signs; fine-motor and sensory disturbance of upper extremity; a combination of imaging and clinical findings is required for the diagnosis; and "reinforcing" (or modifying) factors that can aid in the diagnosis in borderline cases. The LDA model showed the following topics: disturbance to the patient is required for the diagnosis; reinforcing factors can aid in the diagnosis in borderline cases; clinical findings from the extremities; and a combination of imaging and clinical findings is required for the diagnosis. BERTopic identified the following topics: imaging abnormality, typical clinical features, range of objective criteria, and presence of clinical findings.

CONCLUSIONS

This review provides quantifiable data that only a minority of past studies in DCM provided meaningful inclusion criteria. The items and patterns found here are very useful for the development of diagnostic criteria for DCM.

Patient Characteristics Associated With Worsening of Neck Pain-Related Disability After Surgery for Degenerative Cervical Myelopathy: A Nationwide Study of 1508 Patients

BACKGROUND AND OBJECTIVES

Functional status, pain, and quality of life usually improve after surgery for degenerative cervical myelopathy (DCM), but a subset of patients report worsening. The objective was to define cutoff values for worsening on the Neck Disability Index (NDI) and identify prognostic factors associated with worsening of pain-related disability 12 months after DCM surgery.

METHODS

In this prognostic study based on prospectively collected data from the Norwegian Registry for Spine Surgery, the NDI was the primary outcome. Receiver operating characteristics curve analyses were used to obtain cutoff values, using the global perceived effect scale as an external anchor. Univariable and multivariable analyses were performed using mixed logistic regression to evaluate the relationship between potential prognostic factors and the NDI.

RESULTS

Among the 1508 patients undergoing surgery for myelopathy, 1248 (82.7%) were followed for either 3 or 12 months. Of these, 317 (25.4%) were classified to belong to the worsening group according to the mean NDI percentage change cutoff of 3.3. Multivariable analyses showed that smoking (odds ratio [OR] 3.4: 95% CI 1.2-9.5: P < .001), low educational level (OR 2.5: 95% CI 1.0-6.5: P < .001), and American Society of Anesthesiologists grade >II (OR 2.2: 95% CI 0.7-5.6: P = .004) were associated with worsening. Patients with more severe neck pain (OR 0.8: 95% CI 0.7-1.0: P = .003) and arm pain (OR 0.8: 95% CI 0.7-1.0; P = .007) at baseline were less likely to report worsening.

CONCLUSION

We defined a cutoff value of 3.3 for worsening after DCM surgery using the mean NDI percentage change. The independent prognostic factors associated with worsening of pain-related disability were smoking, low educational level, and American Society of Anesthesiologists grade >II. Patients with more severe neck and arm pain at baseline were less likely to report worsening at 12 months.

The significance of metabolic disease in degenerative cervical myelopathy: a systematic review

Introduction

Degenerative cervical myelopathy (DCM) is a form of chronic spinal cord injury, with a natural history of potential for progression over time. Whilst driven by mechanical stress on the spinal cord from degenerative and congenital pathology, the neurological phenotype of DCM is likely to be modified by multiple systemic factors. The role of metabolic factors is therefore of interest, particularly given that ischaemia is considered a key pathological mechanism of spinal cord injury. The objective was therefore to synthesise current evidence on the effect of metabolism on DCM susceptibility, severity, and surgical outcomes.

Methods

A systematic review in MEDLINE and Embase was conducted following PRISMA guidelines. Full-text papers in English, with a focus on DCM and metabolism, including diabetes, cardiovascular disease, anaemia, and lipid profile, were eligible for inclusion. Risk of methodological bias was assessed using the Joanna Briggs Institute (JBI) critical assessment tools. Quality assessments were performed using the GRADE assessment tool. Patient demographics, metabolic factors and the relationships between metabolism and spinal cord disease, spinal column disease and post-operative outcomes were assessed.

Results

In total, 8,523 papers were identified, of which 57 met criteria for inclusion in the final analysis. A total of 91% (52/57) of included papers assessed the effects of diabetes in relation to DCM, of which 85% (44/52) reported an association with poor surgical outcomes; 42% of papers (24/57) discussed the association between cardiovascular health and DCM, of which 88% (21/24) reported a significant association. Overall, DCM patients with diabetes or cardiovascular disease experienced greater perioperative morbidity and poorer neurological recovery. They were also more likely to have comorbidities such as obesity and hyperlipidaemia.

Conclusion

Metabolic factors appear to be associated with surgical outcomes in DCM. However, evidence for a more specific role in DCM susceptibility and severity is uncertain. The pathophysiology and natural history of DCM are critical research priorities; the role of metabolism is therefore a key area for future research focus.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021268814.

Classification and prognostic factors of patients with cervical spondylotic myelopathy after surgical treatment: a cluster analysis

Identifying potential prognostic factors of CSM patients could improve doctors' clinical decision-making ability. The study retrospectively collected the baseline data of population characteristics, clinical symptoms, physical examination, neurological function and quality of life scores of patients with CSM based on the clinical big data research platform. The modified Japanese Orthopedic Association (mJOA) score and SF-36 score from the short-term follow-up data were entered into the cluster analysis to characterize postoperative residual symptoms and quality of life. Four clusters were yielded representing different patterns of residual symptoms and quality of patients' life. Patients in cluster 2 (mJOA RR 55.8%) and cluster 4 (mJOA RR 55.8%) were substantially improved and had better quality of life. The influencing factors for the better prognosis of patients in cluster 2 were young age (50.1 ± 11.8), low incidence of disabling claudication (5.0%) and pathological signs (63.0%), and good preoperative SF36-physiological function score (73.1 ± 24.0) and mJOA socre (13.7 ± 2.8); and in cluster 4 the main influencing factor was low incidence of neck and shoulder pain (11.7%). We preliminarily verified the reliability of the clustering results with the long-term follow-up data and identified the preoperative features that were helpful to predict the prognosis of the patients. This study provided reference and research basis for further study with a larger sample data, extracting more patient features, selecting more follow-up nodes, and improving clustering algorithm.

Diagnostic and prognostic significance of preoperative evoked potential tests in degenerative cervical myelopathy

BACKGROUND CONTEXT

Decompression surgery is a treatment option for patients with degenerative cervical myelopathy (DCM). Surgical decisions primarily depend on clinical symptoms and radiological examinations. The diagnostic and prognostic significance of evoked potential tests for surgical outcomes in patients with DCM has not been thoroughly examined.

PURPOSE

To identify the diagnostic and prognostic significance of preoperative evoked potential tests in patients with DCM who underwent decompression surgery.

STUDY DESIGN

This was a retrospective observational study.

PATIENT SAMPLE

One hundred two consecutive patients who underwent evoked potential tests and surgical treatment between January 2016 and December 2020 in a single spine center and had a minimum follow-up of 6 months.

OUTCOME MEASURES

Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery.

METHODS

This study evaluated the preoperative central motor conduction time (CMCT), somatosensory evoked potentials, and Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery.

RESULTS

Abnormal CMCT findings were observed in 94 patients (92.2%). Abnormal somatosensory evoked potentials were observed in 77 patients (75.5%). There was a statistically significant correlation between preoperative JOA score and abductor pollicis brevis (APB)-CMCT (r=-0.546, p=.001), tibialis anterior (TA)-CMCT (r=-0.517, p<.001), median nerve (MN)-SSEP (r=-0.353, p=.001), and tibial nerve (TN)-SSEP (r=-0.349, p=.003). There were significant differences in recovery rates associated with diabetes mellitus (DM), preoperative severity of myelopathy, TA-CMCT, MN-SSEP, and TN-SSEP. Stepwise multiple regression analysis showed that the major factors affecting the clinical outcomes were TN-SSEP (β=0.327, p=.004), preoperative JOA score (β=0.278, p=.012), and DM (β=0.241, p=.025).

CONCLUSIONS

Evoked potential testing is a functional diagnostic tool that can indicate the severity of myelopathic symptoms in patients with DCM. Additionally, preoperative TN-SSEP may have significant prognostic value in predicting postoperative clinical outcomes. Thus, preoperative evoked potential tests could be helpful for determining suitable surgical treatment candidates and forecasting postoperative prognosis.

Developing predictive models for surgical outcomes in patients with degenerative cervical myelopathy: a comparison of statistical and machine learning approaches

BACKGROUND CONTEXT

Machine learning (ML) is widely used to predict the prognosis of numerous diseases.

PURPOSE

This retrospective analysis aimed to develop a prognostic prediction model using ML algorithms and identify predictors associated with poor surgical outcomes in patients with degenerative cervical myelopathy (DCM).

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

A total of 406 symptomatic DCM patients who underwent surgical decompression were enrolled and analyzed from three independent medical centers.

OUTCOME MEASURES

We calculated the area under the curve (AUC), classification accuracy, sensitivity, and specificity of each model.

METHODS

The Japanese Orthopedic Association (JOA) score was obtained before and 1 year following decompression surgery, and patients were grouped into good and poor outcome groups based on a cut-off value of 60% based on a previous study. Two datasets were fused for training, 1 dataset was held out as an external validation set. Optimal feature-subset and hyperparameters for each model were adjusted based on a 2,000-resample bootstrap-based internal validation via exhaustive search and grid search. The performance of each model was then tested on the external validation set.

RESULTS

The Support Vector Machine (SVM) model showed the highest predictive accuracy compared to other methods, with an AUC of 0.82 and an accuracy of 75.7%. Age, sex, disease duration, and preoperative JOA score were identified as the most commonly selected features by both the ML and statistical models. Grid search optimization for hyperparameters successfully enhanced the predictive performance of each ML model, and the SVM model still had the best performance with an AUC of 0.93 and an accuracy of 86.4%.

CONCLUSIONS

Overall, the study demonstrated that ML classifiers such as SVM can effectively predict surgical outcomes for patients with DCM while identifying associated predictors in a multivariate manner.

Time course of symptomatic improvement after open-door laminoplasty for cervical spondylotic myelopathy

BACKGROUND

Postoperative outcomes following cervical spondylotic myelopathy (CSM) are excellent overall, but there are few prospective studies using patient-reported outcome measures that have explored how long improvement can be expected after surgery. The aim of this prospective study was to investigate from when and until when symptoms improve after open-door laminoplasty in patients with CSM and the factors that affect surgical outcomes.

METHODS

The subjects were 115 CSM patients who underwent laminoplasty. The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) was used for longitudinal evaluation, and surveys on cervical spine function, upper extremity function, lower extremity function, bladder function, and quality of life were conducted before surgery and at 3, 6, 12, 18, and 24 months after surgery. The patients were classified into 'effective' and 'ineffective' groups based on the points obtained for each domain, and the factors affecting the outcome of surgery were examined by multivariate analysis.

RESULTS

JOACMEQ scores improved significantly at 3 months postoperatively compared to preoperatively for all four domains except cervical spine function, but there was no significant improvement after 3 months postoperatively. Multivariate analysis showed that the preoperative score (cervical spine function and upper extremity function) and the points obtained at 3 months postoperatively (upper and lower extremity function, bladder function, and quality of life) were the factors associated with membership of the effective group at 24 months postoperatively.

CONCLUSIONS

Although upper and lower extremity function, bladder function, and quality of life domains improved in the relatively early postoperative period, improvement after 3 months postoperatively was limited. The results suggest that the preoperative score and the superiority of the improvement obtained up to 3 months after surgery may be indicators of postoperative outcomes, and this may provide new insights into the selection of surgical indications and patient explanations.

Pathophysiology and surgical decision-making in central cord syndrome and degenerative cervical myelopathy: correcting the somatotopic fallacy

Our understanding of Central Cord Syndrome (CCS), a form of incomplete spinal cord injury characterized by disproportionate upper extremity weakness, is evolving. Recent advances challenge the traditional somatotopic model of corticospinal tract organization within the spinal cord, suggesting that CCS is likely a diffuse injury rather than focal lesion. Diagnostic criteria for CCS lack consensus, and varied definitions impact patient identification and treatment. Evidence has mounted for early surgery for CCS, although significant variability persists in surgical timing preferences among practitioners. A demographic shift toward an aging population has increased the overlap between CCS and Degenerative Cervical Myelopathy (DCM). Understanding this intersection is crucial for comprehensive patient care. Assessment tools, including quantitative measures and objective evaluations, aid in distinguishing CCS from DCM. The treatment landscape for CCS in the context of pre-existing DCM is complex, requiring careful consideration of pre-existing neurologic injury, patient factors, and injury factors. This review synthesizes emerging evidence, outlines current guidelines in diagnosis and management, and emphasizes the need for ongoing research to refine our understanding and treatment strategies for this evolving patient population.

Cervical muscle morphometry and composition demonstrate prognostic value in degenerative cervical myelopathy outcomes

Objectives

This study aimed to examine whether preoperative cervical muscle size, composition, and asymmetry from magnetic resonance imaging (MRI) can predict post-operative outcomes in patients with degenerative cervical myelopathy (DCM).

Methods

A total of 171 patients with DCM were included. Relative total cross-sectional area (RCSA), functional CSA (fat-free area, FCSA), ratio of FCSA/CSA (fatty infiltration) and asymmetry of the multifidus (MF) and semispinalis cervicis (SCer) together (MF + SCer), and cervical muscle as a group (MF, SCer, semispinalis capitis, and splenius capitis) were obtained from T2-weighted axial MR images at the mid-disk, at the level of maximum cord compression and the level below. Univariate and multivariate linear regression analyses were used to assess the relationship between baseline cervical muscle measurements of interest with the modified Japanese Orthopedic Association (mJOA), Nurick Classification, Neck Disability Index (NDI), and SF-36 health survey at 6-month and 12-month post-surgery.

Results

Lower RCSA of MF + SCer, less CSA MF + SCer asymmetry and greater FCSA/CSA for the cervical muscle group (e.g., less fatty infiltration), and younger age were significant predictors of higher mJOA scores (e.g., less disability) at 6-month and 12-month post-surgery (all p < 0.05). Greater CSA asymmetry in MF + SCer and lower FCSA/CSA (e.g., more fatty infiltration) for the cervical muscle group were significant predictors of higher Nurick scores (e.g., more disability) at 6-month and 12-month post-surgery (all p < 0.05). Lower FCSA MF + Scer asymmetry, lower FCSA/CSA asymmetry of the muscle group, and greater RCSA MF + SCer were significant predictors of higher NDI scores at 6-month and 12-month post-surgery. Finally, greater FCSA/CSA asymmetry of the MF + SCer, greater FCSA asymmetry of the muscle group, greater RCSA of the muscle group, and greater CSA asymmetry of MF + SCer were significant predictors of lower post-operative SF-36 scores at 6- and 12-month post-surgery.

Conclusion

Our result suggested that cervical paraspinal muscle morphology, specifically greater asymmetry, and fatty infiltration may be important predictors of functional recovery and post-surgical outcomes in patients with DCM.

Osteopathy in the Early Diagnosis and Management of Degenerative Cervical Myelopathy: National Survey

BACKGROUND

Degenerative cervical myelopathy (DCM) is a common and disabling neurodegenerative condition. Surgical decompression is the only evidence-based treatment to halt disease progression; however, diagnosis and access to timely treatment are often delayed, which contribute to significant disability and dependence. Supporting early diagnosis and access to timely treatment is a critical priority. Exploring these challenges, Myelopathy.org has observed that people with DCM may seek osteopathy care for their symptoms, both before and after diagnosis.

OBJECTIVE

This study aimed to describe the current interaction between osteopaths and people with DCM and understand how this may be targeted to enhance the DCM diagnostic pathway.

METHODS

Registered osteopaths in the United Kingdom completed a web-based survey hosted by the Institute of Osteopathy, as part of their institute's 2021 census. Responses were collected from February to May 2021. Demographic information about the respondents was captured, including age, gender, and ethnicity. Professional information captured included the year of qualification; region of practice; type of practice; and number of undiagnosed, operated diagnosed, and unoperated diagnosed DCM cases encountered per year. The completion of the survey was voluntary; however, a prize draw incentive was offered to participants.

RESULTS

The demographics were heterogenous for the 547 practitioners who completed the survey. There was representation from a wide range of demographic groups, including the level of experience, gender, age, and the region of United Kingdom. At least 68.9% (377/547) of osteopaths reported encounters with DCM each year. Osteopaths most frequently encountered patients with undiagnosed DCM, with a mean of 3 patient encounters per year. This compares to 2 encounters per year with patients with diagnosed DCM. The level of practitioner experience was positively correlated with the detection of undiagnosed DCM (P<.005). The influence of practitioner experience was corroborated by a subgroup analysis looking at the relationship between practitioner age on the detection of undiagnosed DCM. Osteopaths older than 54 years encountered an average of 4.2 cases per year, whereas those younger than 35 years detected 2.9 cases per year. Osteopaths in private clinics reported encounters with a greater mean number (4.4) of undiagnosed DCM cases per year than osteopaths in other clinic types (3.0).

CONCLUSIONS

Osteopaths reported that they frequently consult people with DCM, including those suspected to have undiagnosed or presurgical DCM. Given this concentrated presentation of early DCM and a workforce professionally trained to examine musculoskeletal disease, osteopaths could have an important role in accelerating access to timely treatment. We included a decision support tool and specialist referral template as a tool to support onward care.

Diffusion basis spectrum imaging predicts long-term clinical outcomes following surgery in cervical spondylotic myelopathy

BACKGROUND CONTEXT

A major shortcoming in improving care for cervical spondylotic myelopathy (CSM) patients is the lack of robust quantitative imaging tools to guide surgical decision-making. Diffusion basis spectrum imaging (DBSI), an advanced diffusion-weighted MRI technique, provides objective assessments of white matter tract integrity that may help prognosticate outcomes in patients undergoing surgery for CSM.

PURPOSE

To examine the ability of DBSI to predict clinically important CSM outcome measures at 2-years follow-up.

STUDY DESIGN/SETTING

Prospective cohort study.

PATIENT SAMPLE

Patients undergoing decompressive cervical surgery for CSM.

OUTCOME MEASURES

Neurofunctional status was assessed by the mJOA, MDI, and DASH. Quality-of-life was measured by the SF-36 PCS and SF-36 MCS. The NDI evaluated self-reported neck pain, and patient satisfaction was assessed by the NASS satisfaction index.

METHODS

Fifty CSM patients who underwent cervical decompressive surgery were enrolled. Preoperative DBSI metrics assessed white matter tract integrity through fractional anisotropy, fiber fraction, axial diffusivity, and radial diffusivity. To evaluate extra-axonal diffusion, DBSI measures restricted and nonrestricted fractions. Patient-reported outcome measures were evaluated preoperatively and up to 2-years follow-up. Support vector machine classification algorithms were used to predict surgical outcomes at 2-years follow-up. Specifically, three feature sets were built for each of the seven clinical outcome measures (eg, mJOA), including clinical only, DBSI only, and combined feature sets.

RESULTS

Twenty-seven mild (mJOA 15-17), 12 moderate (12-14) and 11 severe (0-11) CSM patients were enrolled. Twenty-four (60%) patients underwent anterior decompressive surgery compared with 16 (40%) posterior approaches. The mean (SD) follow-up was 23.2 (5.6, range 6.1-32.8) months. Feature sets built on combined data (ie, clinical+DBSI metrics) performed significantly better for all outcome measures compared with those only including clinical or DBSI data. When predicting improvement in the mJOA, the clinically driven feature set had an accuracy of 61.9 [61.6, 62.5], compared with 78.6 [78.4, 79.2] in the DBSI feature set, and 90.5 [90.2, 90.8] in the combined feature set.

CONCLUSIONS

When combined with key clinical covariates, preoperative DBSI metrics predicted improvement after surgical decompression for CSM with high accuracy for multiple outcome measures. These results suggest that DBSI may serve as a noninvasive imaging biomarker for CSM valuable in guiding patient selection and informing preoperative counseling.

LEVEL OF EVIDENCE

II.

Predictors of poor clinical outcome in patients with cervical spondylotic myelopathy undergoing cervical laminectomy and fusion

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a common degenerative disease that arises from spinal cord compression and injury. Laminectomy with posterior spinal fusion (LPSF) is one of the most common approaches used to treat patients with CSM. The present study aimed to evaluate predictors of poor clinical outcome in patients with CSM undergoing LPSF.

METHODS

We retrospectively evaluated 157 patients with CSM who underwent LPSF at our center between April 2014 and June 2019. The neurological outcome was assessed using the modified Japanese Orthopaedic Association (mJOA) scale before the surgery and at the last follow-up visit. Based on the clinical outcomes, all patients were divided into two groups [the good group (recovery rates ≥ 75%) and the poor group (recovery rates < 75%)]. The following suggested variables as potential predictors for the poor clinical outcome were compared between the two groups:age, gender, body mass index (BMI), smoking, diabetes, number of laminectomy levels, presence of signal changes in Magnetic Resonance Imaging (MRI), duration of symptoms, preoperative JOA scale, preoperative Pavlov ratio, preoperative cervical curvature, and preoperative cervical range of motion (ROM).

RESULTS

There were 86 males (54.8%) and 71 females (45.2%) with the mean follow-up time of 24.96 ± 1.67 months. Overall, 114 patients (72.6%) had a good clinical outcome. However, 43 subjects (27.4%) failed to achieve a good outcome. According to the binary logistic regression analysis, age (odds ratio [OR], 2.14; 95% confidence interval [95% CI], 1.87-2.63; P = 0.014) and preoperative JOA scale (OR, 3.73; 95% CI 2.96-4.87; p < 0.001) were independent predictors of poor clinical outcome.

CONCLUSIONS

The results of the present study showed that age and preoperative JOA scale were predictors of poor clinical outcome in patients with CSM undergoing LPSF. These findings will be of great value in preoperative counseling and management of postoperative expectations.

Technical Aspects of Intra-Operative Ultrasound for Spinal Cord Injury and Myelopathy: A Practical Review

OBJECTIVES

To compile intra-operative techniques, established imaging parameters, available equipment and software, and clinical applications of intraoperative ultrasound imaging (IOUSI) for spinal cord injury (SCI) and myelopathy.

METHODS

PubMed and Google Scholar were searched for relevant articles. The articles were reviewed and selected by 2 independent researchers. After article selection, data were extracted and summarized into research domains. PRISMA systematic review process was followed.

RESULTS

Of the 2477 articles screened, 16 articles met the inclusion criteria. In patients with SCI and myelopathy, common quantitative measurements obtained using IOUSI were noted: 1) ultrasound elastography, 2) midsagittal anteroposterior diameter, 3) transverse, 4) transverse diameter, 5) maximum spinal cord compression, and 6) compression ratioTo ensure adequate decompression and to look for residual compression, the lateral and the craniocaudal margins of the laminectomy site were inspected in both axial and sagittal planes. In instances where quantitative assessment was not possible, cord decompression and degree of residual compression were gauged by inspecting the interface between the ventral border of the spinal cord and any potentially compressive elements, and by searching for symmetric and rhythmic cerebrospinal fluid pulsations. Use of contrast-enhanced ultrasoundand molecular imaging are additional advances in objective assessments for SCI and myelopathy.

CONCLUSIONS

This review outlines the potential of IOUSI in patients presenting with SCI and myelopathy. Moreover, by identifying potential for inter-operator variability in certain subjective measurements, we illustrate the need for further research to quantify and standardize those assessments.

Influence of clinical and radiological parameters on the likelihood of neurological improvement after surgery for degenerative cervical myelopathy

OBJECTIVE

Degenerative cervical myelopathy (DCM) is routinely treated with surgical decompression, but disparate postoperative outcomes are frequently observed, ranging from complete neurological recovery to persistent decline. Although numerous clinical and radiological factors have been independently associated with failure to improve, the relative impact of these proposed risk factors remains obscure. In this study, the authors assess the combined role of clinical and radiographic parameters in contributing to failure to attain neurological improvement after surgery.

METHODS

A consecutive series of patients who underwent surgery for DCM between July 2013 and August 2018 at a single institution was identified from a prospectively maintained database. Retrospective chart review was undertaken to record perioperative clinical and radiographic parameters. Failure to improve on the last follow-up evaluation after surgery, defined as a change in modified Japanese Orthopaedic Association (mJOA) score less than 2, was the primary outcome in univariate and multivariate analyses.

RESULTS

The authors included 183 patients in the final cohort. In total, 109 (59.6%) patients improved (i.e., responders with ΔmJOA score ≥ 2) after surgery and 74 (40.4%) were nonresponders with ΔmJOA score < 2. Baseline demographic variables and comorbidity rates were similar, whereas baseline Nurick score was the only clinical variable that differed between responders and nonresponders (2.7 vs 3.0, p = 0.02). In contrast, several preoperative radiographic variables differed between the groups, including presence and degree of cervical kyphosis, number of levels with bidirectional cord compression, presence and number of levels with T2-weighted signal change, intramedullary lesion (IML) length, Torg ratio, and both narrowest spinal canal and cord diameter. On multivariate analysis, preoperative degree of kyphosis at C2-7 (OR 1.19, p = 0.004), number of levels with bidirectional compression (OR 1.83, p = 0.003), and IML length (OR 1.14, p < 0.001) demonstrated the highest predictive power for nonresponse (area under the receiver operating characteristic curve 0.818). A risk factor point system that predicted failure of improvement was derived by incorporating these 3 variables.

CONCLUSIONS

When a large spectrum of both clinical and radiographic variables is considered, the degree of cervical kyphosis, number of levels with bidirectional compression, and IML length are the most predictive of nonresponse after surgery for DCM. Assessment of these radiographic factors can help guide surgical decision-making and more appropriately stratify patients in clinical trials.

Lateral Approach to the Cervical Spine to Manage Degenerative Cervical Myelopathy and Radiculopathy

BACKGROUND

The cervical lateral approach can enlarge the spinal canal and foramen to achieve an effective neural decompression without needing spine stabilization. For this review, the authors' main objective was to illustrate the rationale, advantages, disadvantages, complications, and pitfalls of this technique, highlighting also areas for future development.

MATERIALS AND METHODS

A Medline via PubMed database search was carried out by using both keywords, namely "cervical oblique corpectomy," "multilevel oblique corpectomy and foraminotomy," and "lateral vertebrectomy," and Medical Subject Headings (MeSH) terms from 1 January 1991, up to 31 December 2021.

RESULTS

The analyzed articles suggested that the use of such a technique has declined over time; only 29 clinical studies met all the inclusion criteria and were retained for data analysis, including 1200 patients undergoing such an approach for the management of degenerative cervical myelopathies (DCMs) or of radiculopathies. The main etiopathogeneses were cervical stenosis, degenerative disk disease, or a mix of them-78% of which had a favorable outcome; the most frequent complications were transient and permanent Horner syndrome in 13.6% and 9.2% of cases, respectively. Long-term stability was reported in 97% of patients.

CONCLUSION

Multilevel cervical oblique vertebrectomy and/or lateral foraminotomy allow wide neural structure decompression and optimal stability given that the physiological spinal motion is preserved.

Prognostic effect of increased postoperative MRI T2WI high signal intensity in degenerative cervical myelopathy

BACKGROUND CONTEXT

High cord signals (HCS) are common in patients undergoing surgery for degenerative cervical myelopathy (DCM). Few studies have investigated the prognostic effects of postoperative HCS changes.

PURPOSE

To investigate whether different changes in the postoperative magnetic resonance imaging (MRI) T2-weighted images (T2WIs) signal intensity ratio (SIR) is related to patient outcomes, predictors of unsatisfactory recovery, and the factors associated with changes in postoperative SIR.

STUDY DESIGN

A retrospective chart review at a single institution.

PATIENT SAMPLE

The study population included all consecutive patients who showed HCS in preoperative MRI T2WIs and underwent double-door laminoplasty for DCM from December 2017 to December 2020.

OUTCOME MEASURES

Patient self-reported measures included the Japanese Orthopedic Association (JOA) score, 36-Item Short Form Survey (SF-36) physical component score, and SF-36 mental component score. Imaging measures included SIR, length of HCS, and canal narrowing ratio (CNR).

METHODS

We reviewed patient records and analyzed the statistical associations of MRI T2WI measures with the JOA score, SF-36 physical, and mental component scores.

RESULTS

Fifty-three patients were categorized into three groups based on the postoperative HCS changes, identified from MRI T2WI before and after surgery: reduced (Group A, N=26); unchanged (Group B, N=12); and increased (Group C, N=15). The neurological recovery rates 12 months after surgery were 67.72%±17.45% in Group A, 51.53%±16.00% in Group B, and 13.35%±21.35% in Group C (p<.001). Significant differences across the three groups were found in symptom duration, postoperative SIR and length of HCS, pre- and postoperative CNR, recovery rate, JOA, SF-36 scores, with patients in Group C having the worst outcomes. Longer DCM symptom duration, greater preoperative CNR, and increased postoperative HCS were prognostic factors for a recovery rate<50%. Preoperative CNR, with an optimal threshold of 57.303%, was an independent risk factor for increased postoperative HCS.

CONCLUSIONS

Less than one-third of DCM patients with preoperative HCS exhibited an increase in HCS after double-door laminoplasty and reported worse outcomes at the 12-month follow-up when compared to patients with decreased or unchanged postoperative HCS.

Quantitative physical performance tests can effectively detect Degenerative Cervical Myelopathy: A systematic review and meta-analysis

PURPOSE

This review aimed to identify effective physical performance tests (PPT) as clinical outcome indicators for detecting and monitoring degenerative cervical myelopathy (DCM).

METHODS

A comprehensive literature search was performed on seven electronic databases on the effectiveness in detection and monitoring of DCM by PPT. All included studies were reviewed and undergone quality assessments on the risk-of-bias by Newcastle-Ottawa Scale and were pooled by random-effect analysis with level of significance at 0.05. Homogeneity among studies was assessed by I²-statistics and effect of PPT was confirmed by Cohen's d effect size and confidence intervals.

RESULTS

Totally, 3111 articles were retrieved, and 19 studies were included for review and meta-analysis. There were 13 studies investigating PPT regarding the upper limbs and 12 studies regarding the lower limbs. Performance in 10-second-Grip-and-Release Test (G&R) and 9-Hole-Peg Test (9HPT) was studied in 10 and 3 articles, respectively, while 10-second-Stepping Test (SST), 30-meter-Walking Test (30MWT) and Foot-Tapping Test (FTT) for lower limbs were studied in 5, 4, and 3 articles correspondingly. Only 1 study utilized the Triangle-Stepping Test. High-quality study with fair risk-of-bias was revealed from Newcastle-Ottawa scale. Large effect size facilitated detection and monitoring in DCM was unveiling for G&R, 9HPT, SST, and 30MWT. FTT, while also effective, was hindered by a high-degree heterogeneity in the meta-analysis.

CONCLUSION

Effective PPT including G&R, 9HPT, SST, 30MWT, and FTT was identified for disease detection and monitoring in DCM.

Do Patients With Chronic Diabetes Have Worse Motor Outcomes After Cervical ASIA C Traumatic Spinal Cord Injury?

STUDY DESIGN

This was a level IV retrospective prognostic study.

OBJECTIVE

The objective of this study was to determine if patients with chronic diabetes have worse functional outcomes and motor recovery after cervical traumatic spinal cord injury (TSCI).

SUMMARY OF BACKGROUND DATA

Diabetes mellitus has multiple deleterious neurological effects and has been shown to worsen elective cervical spine surgery outcomes. Prior literature has scarcely characterized the impact of chronic diabetes on motor and functional outcomes after TSCI.

METHODS

The National Spinal Cord Injury Statistical Center (NSCISC) database was utilized to retrospectively collect data on cervical American Spinal Injury Association (ASIA) C TSCI between 2011 and 2016. Patients were divided into diabetes and nondiabetes groups. Primary outcomes included wheelchair requirement and ambulatory status 1 year after injury. Secondary outcomes were motor score collected at the time of rehab admission, rehab discharge, and 1-year follow-up. All outcome variables were analyzed using univariate and multivariate regression to assess for differences between diabetes and nondiabetes groups and possible confounders.

RESULTS

A total of 219 patients met the inclusion criteria for the study: 193 without diabetes and 26 with diabetes (12.0%). After controlling for confounders, patients with diabetes had had significantly increased wheelchair requirement (83.3% vs. 51.8%, relative risk=1.63, 95% confidence interval: 1.20-1.83, P =0.009 multivariate) and decreased ambulatory rates (50% vs. 67.9%, relative risk=0.55, 95% confidence interval: 0.25-0.98, P =0.042 multivariate) at 1 year. They also had no difference in average total motor scores at rehab admission but significantly worse total motor scores at rehab discharge (50.6±23.3 vs. 60.3±21.4, P =0.033 univariate, P =0.002 multivariate).

CONCLUSIONS

Patients with diabetes have increased wheelchair requirement and decreased ambulatory ability at 1 year after the injury as well as diminished recovery in motor scores after motor-incomplete cervical TSCI. These patients may be targets for aggressive diabetic screening and intervention to minimize negative outcomes.

Long-term functional outcome of surgical treatment for degenerative cervical myelopathy

OBJECTIVE

Degenerative cervical myelopathy (DCM) is a major global cause of spinal cord dysfunction. Surgical treatment is considered a safe and effective way to improve functional outcome, although information about long-term functional outcome remains scarce despite increasing longevity. The objective of this study was to describe functional outcome 10 years after surgery for DCM.

METHODS

A prospective observational cohort study was undertaken in a university-affiliated neurosurgery department. All patients who underwent surgery for DCM between 2008 and 2010 as part of the multicenter Cervical Spondylotic Myelopathy International trial were included. Participants were approached for additional virtual assessment 10 years after surgery. Functional outcome was assessed according to the modified Japanese Orthopaedic Association (mJOA; scores 0-18) score at baseline and 1, 2, and 10 years after surgery. The minimal clinically important difference was defined as 1-, 2-, or 3-point improvement for mild, moderate, and severe myelopathy, respectively. Outcome was considered durable when stabilization or improvement after 2 years was maintained at 10 years. Self-evaluated effect of surgery was assessed using a 4-point Likert-like scale. Demographic, clinical, and surgical data were compared between groups that worsened and improved or remained stable using descriptive statistics. Functional outcome was compared between various time points during follow-up with linear mixed models.

RESULTS

Of the 42 originally included patients, 37 participated at follow-up (11.9% loss to follow-up, 100% response rate). The mean patient age was 56.1 years, and 42.9% of patients were female. Surgical approaches were anterior (76.2%), posterior (21.4%), or posterior with fusion (2.4%). The mean follow-up was 10.8 years (range 10-12 years). The mean mJOA score increased significantly from 13.1 (SD 2.3) at baseline to 14.2 (SD 3.3) at 10 years (p = 0.01). A minimal clinically important difference was achieved in 54.1%, and stabilization of functional status was maintained in 75.0% in the long term. Patients who worsened were older (median 63 vs 52 years, p < 0.01) and had more comorbidities (70.0% vs 25.9%, p < 0.01). A beneficial effect of surgery was self-reported by 78.3% of patients.

CONCLUSIONS

Surgical treatment for DCM results in satisfactory improvement of functional outcome that is maintained at 10-year follow-up.

Optimizing the Application of Surgery for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 10]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To introduce the number 10 research priority for Degenerative Cervical Myelopathy: Individualizing Surgery.

METHODS

This article summarizes the current recommendations and indications for surgery, including how known prognostic factors such as injury time, age, disease severity, and associated comorbidities impact surgical outcome. It also considers key areas of uncertainty that should be the focus of future research.

RESULTS

While a small proportion of conservatively managed patients may remain stable, the majority will deteriorate over time. To date, surgical decompression is the mainstay of treatment, able to halt disease progression and improve neurologic function and quality of life for most patients. Whilst this recognition has led to recommendations on when to offer surgery, there remain many uncertainties including the type of surgery, or timing in milder and/or asymptomatic cases. Their clarification has the potential to transform outcomes, by ensuring surgery offers each individual its maximum benefit.

CONCLUSION

Developing the evidence to better guide surgical decision-making at the individual patient level is a research priority for Degenerative Cervical Myelopathy.

Improving Assessment of Disease Severity and Strategies for Monitoring Progression in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 4]

STUDY DESIGN

Narrative Review.

OBJECTIVE

To (i) discuss why assessment and monitoring of disease progression is critical in Degenerative cervical myelopathy (DCM); (ii) outline the important features of an ideal assessment tool and (iii) discuss current and novel strategies for detecting subtle deterioration in DCM.

METHODS

Literature review.

RESULTS

Degenerative cervical myelopathy is an overarching term used to describe progressive injury to the cervical spinal cord by age-related changes of the spinal axis. Based on a study by Smith et al (2020), the prevalence of DCM is approximately 2.3% and is expected to rise as the global population ages. Given the global impact of this disease, it is essential to address important knowledge gaps and prioritize areas for future investigation. As part of the AO Spine RECODE-DCM (Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy) project, a priority setting partnership was initiated to increase research efficiency by identifying the top ten research priorities for DCM. One of the top ten priorities for future DCM research was: What assessment tools can be used to evaluate functional impairment, disability and quality of life in people with DCM? What instruments, tools or methods can be used or developed to monitor people with DCM for disease progression or improvement either before or after surgical treatment?

CONCLUSIONS

With the increasing prevalence of DCM, effective surveillance of this population will require both the implementation of a monitoring framework as well as the development of new assessment tools.

Is surgery beneficial for patients with concurrent multiple sclerosis and degenerative cervical myelopathy? A review of literature

Introduction

Due to an overlap in symptoms, there is significant delay in surgical treatment of patients that have concomitant multiple sclerosis (MS) and degenerative cervical Myelopathy (DCM). The purpose of this review is to evaluate if surgical intervention is beneficial to patients that have concurrent presentations.

Research question

Is surgery beneficial in concurrent MS and DCM?

Materials and methods

A literature search with no date restrictions was conducted on Pubmed and Medline databases. Keywords searched: Degenerative Cervical Myelopathy, Multiple sclerosis, Treatment, Surgery, Quality of Life. Randomised controlled trials, prospective, retrospective, and case series reporting timing of surgery, post-operative outcomes such as improvement in myelopathic symptoms, quality of life, and any serious complications were included.

Results

The literature search yielded a total of 8 studies across all databases. Seven articles were selected for full text review, and all of them were sectioned for inclusion in this review. Seven studies evaluated 160 participants with concurrent multiple sclerosis and degenerative cervical myelopathy. Earlier studies had discouraged performing surgery in this subset of patients, the majority of studies found it worthwhile to perform early surgery for patients with concomitant multiple sclerosis and degenerative cord compression, if the patients had radiculopathy. Quality of life for MS patients did not improve as much as it did for patients that did not have MS.

Discussion and conclusion

Patients with radiculopathy, neck pain and cord compression are most likely to benefit from early surgery. There is no need for delaying to offer surgery unless other medical/anaesthetic contraindications exist.

Machine Learning Approach in Predicting Clinically Significant Improvements After Surgery in Patients with Cervical Ossification of the Posterior Longitudinal Ligament

STUDY DESIGN

A retrospective analysis of prospectively collected data.

OBJECTIVE

This study aimed to create a prognostic model for surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) using machine learning (ML).

SUMMARY OF BACKGROUND DATA

Determining surgical outcomes helps surgeons provide prognostic information to patients and manage their expectations. ML is a mathematical model that finds patterns from a large sample of data and makes predictions outperforming traditional statistical methods.

METHODS

Of 478 patients, 397 and 370 patients had complete follow-up information at 1 and 2 years, respectively, and were included in the analysis. A minimal clinically important difference (MCID) was defined as an acquired Japanese Orthopedic Association (JOA) score of ≥2.5 points, after which a ML model that predicts whether MCID can be achieved 1 and 2 years after surgery was created. Patient background, clinical symptoms, and imaging findings were used as variables for analysis. The ML model was created using LightGBM, XGBoost, random forest, and logistic regression, after which the accuracy and area under the receiver-operating characteristic curve (AUC) were calculated.

RESULTS

The mean JOA score was 10.3 preoperatively, 13.4 at 1 year after surgery, and 13.5 at 2 years after surgery. XGBoost showed the highest AUC (0.72) and high accuracy (67.8) for predicting MCID at 1 year, whereas random forest had the highest AUC (0.75) and accuracy (69.6) for predicting MCID at 2 years. Among the included features, total preoperative JOA score, duration of symptoms, body weight, sensory function of the lower extremity sub-score of the JOA, and age were identified as having the most significance in most of ML models.

CONCLUSION

Constructing a prognostic ML model for surgical outcomes in patients with OPLL is feasible, suggesting the potential application of ML for predictive models of spinal surgery.Level of Evidence: 4.

Association of ≥ 12 months of delayed surgical treatment for cervical myelopathy with worsened postoperative outcomes: a multicenter analysis of the Quality Outcomes Database

OBJECTIVE

Degenerative cervical myelopathy (DCM) results in significant morbidity. The duration of symptoms prior to surgical intervention may be associated with postoperative surgical outcomes and functional recovery. The authors' objective was to investigate whether delayed surgical treatment for DCM is associated with worsened postoperative outcomes.

METHODS

Data from 1036 patients across 14 surgical centers in the Quality Outcomes Database were analyzed. Baseline demographic characteristics and findings of preoperative and postoperative symptom evaluations, including duration of symptoms, were assessed. Postoperative functional outcomes were measured using the Neck Disability Index (NDI) and modified Japanese Orthopaedic Association (mJOA) scale. Symptom duration was classified as either less than 12 months or 12 months or greater. Univariable and multivariable regression were used to evaluate for the associations between symptom duration and postoperative outcomes.

RESULTS

In this study, 513 patients (49.5%) presented with symptom duration < 12 months, and 523 (50.5%) had symptoms for 12 months or longer. Patients with longer symptom duration had higher BMI and higher prevalence of anxiety and diabetes (all p < 0.05). Symptom duration ≥ 12 months was associated with higher average baseline NDI score (41 vs 36, p < 0.01). However, improvements in NDI scores from baseline were not significantly different between groups at 3 months (p = 0.77) or 12 months (p = 0.51). Likewise, the authors found no significant differences between groups in changes in mJOA scores from baseline to 3 months or 12 months (both p > 0.05).

CONCLUSIONS

Surgical intervention resulted in improved mJOA and NDI scores at 3 months, and this improvement was sustained in both patients with short and longer initial symptom duration. Patients with DCM can still undergo successful surgical management despite delayed presentation.

Machine learning algorithms for prediction of health-related quality-of-life after surgery for mild degenerative cervical myelopathy

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction worldwide. Current guidelines recommend management based on the severity of myelopathy, measured by the modified Japanese Orthopedic Association (mJOA) score. Patients with moderate to severe myelopathy, defined by an mJOA below 15, are recommended to undergo surgery. However, the management for mild myelopathy (mJOA between 15 and 17) is controversial since the response to surgery is more heterogeneous.

PURPOSE

To develop machine learning algorithms predicting phenotypes of mild myelopathy patients that would benefit most from surgery.

STUDY DESIGN

Retrospective subgroup analysis of prospectively collected data.

PATIENT SAMPLES

Data were obtained from 193 mild DCM patients who underwent surgical decompression and were enrolled in the multicenter AOSpine CSM clinical trials.

OUTCOME MEASURES

The mJOA score, an assessment of functional status, was used to isolate patients with mild DCM. The primary outcome measures were change from baseline for the Short Form-36 (SF-36) mental component summary (MCS) and physical component summary (PCS) at 1-year postsurgery. These changes were dichotomized according to whether they exceeded the minimal clinically important difference.

METHODS

The data were split into training (75%) and testing (25%) sets. Model predictors included baseline demographic variables and clinical presentation. Seven machine learning algorithms and a logistic regression model were trained and optimized using the training set, and their performances were evaluated using the testing set. For each outcome (improvement in MCS or PCS), the machine learning algorithm with the greatest area under the curve (AUC) on the training set was selected for further analysis.

RESULTS

The generalized boosted model (GBM) and earth models performed well in the prediction of significant improvement in MCS and PCS respectively, with AUCs of 0.72 to 0.78 on the training set. This performance was replicated on the testing set, in which the GBM and earth models showed AUCs of 0.77 and 0.78, respectively, as well as fair to good calibration across the predicted range of probabilities. Female patients with a low initial MCS were less likely to experience significant improvement in MCS than males. The presence of certain signs and symptoms (eg, lower limb spasticity, clumsy hands) were also predictive of worse outcome.

CONCLUSIONS

Machine learning models showed good predictive power and provided information about the phenotypes of mild DCM patients most likely to benefit from surgical intervention. Overall, machine learning may be a useful tool for management of mild DCM, though external validation and prospective analysis should be performed to better solidify its role.

The influence of ApoE4 on the clinical outcomes and pathophysiology of degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most common cause of nontraumatic spinal cord injury in adults worldwide. Surgical decompression is generally effective in improving neurological outcomes and halting progression of myelopathic deterioration. However, a subset of patients experience suboptimal neurological outcomes. Given the emerging evidence that apolipoprotein E4 (ApoE4) allelic status influences neurodegenerative conditions, we examined whether the presence of the ApoE4 allele may account for the clinical heterogeneity of treatment outcomes in patients with DCM. Our results demonstrate that human ApoE4⁺ DCM patients have a significantly lower extent of improvement after decompression surgery. Functional analysis of our DCM mouse model in targeted-replacement mice expressing human ApoE4 revealed delayed gait recovery, forelimb grip strength, and hind limb mechanical sensitivity after decompression surgery, compared with their ApoE3 counterparts. This was accompanied by an exacerbated proinflammatory response resulting in higher concentrations of TNF-α, IL-6, CCL3, and CXCL9. At the site of injury, there was a significant decrease in gray matter area, an increase in the activation of microglia/macrophages, and increased astrogliosis after decompression surgery in the ApoE4 mice. Our study is the first to our knowledge to investigate the pathophysiological underpinnings of ApoE4 in DCM, which suggests a possible personalized medicine approach for the treatment of DCM in ApoE4 carriers.

Smoking Is an Independent Risk Factor for 90-Day Readmission and Reoperation Following Posterior Cervical Decompression and Fusion

BACKGROUND

Posterior cervical decompression and fusion (PCF) is a common procedure used to treat various cervical spine pathologies, but the 90-d outcomes following PCF surgery continue to be incompletely defined.

OBJECTIVE

To identify risk factors associated with 90-d readmission and reoperation following PCF surgery.

METHODS

Adults undergoing PCF from 2012 to 2020 were identified. Demographic and radiographic data, surgical characteristics, and 90-d outcomes were collected. Univariate analysis was performed using Student's t-test, chi square, and Fisher exact tests as appropriate. Multivariable logistic regression models with lasso penalty were used to analyze various risk factors.

RESULTS

A total of 259 patients were included. The 90-d readmission and reoperation rates were 9.3% and 4.6%, respectively. The most common reason for readmission was surgical site infection (SSI) (33.3%) followed by new neurological deficits (16.7%). Patients who smoked tobacco had 3-fold greater odds of readmission compared to nonsmokers (odds ratio [OR]: 3.48; 95% CI 1.87-6.67; P = .0001). Likewise, the most common reason for reoperation was SSI (33.3%) followed by seroma and implant failure (25.0% each). Smoking was also an independent risk factor for reoperation, associated with nearly 4-fold greater odds of return to the operating room (OR: 3.53; 95% CI 1.53-8.57; P = .003).

CONCLUSION

Smoking is a significant predictor of 90-d readmission and reoperation in patients undergoing PCF surgery. Smoking cessation should be strongly considered preoperatively in elective PCF cases to minimize the risk of 90-d readmission and reoperation.

Long-term Radiologic and Clinical Outcomes after Three-level Contiguous Anterior Cervical Diskectomy and Fusion without Plating: A Multicentric Retrospective Study

BACKGROUND

 Anterior cervical diskectomy and fusion (ACDF) has been providing good surgical, clinical, and radiologic outcomes in patients suffering from cervical degenerative disk disease (DDD). However, the role of anterior plating is still debated, especially in three-level procedures. This study aimed to investigate long-term clinical and radiologic outcomes and complications after three-level contiguous ACDF without plating for cervical DDD.

METHODS

 Two institutional databases were retrieved (January 2009-December 2014) for patients treated with three-level contiguous ACDF without plating. Minimum follow-up (FU) was 5 years. Demographical data, smoking status, implant types, Neck Disability Index (NDI), visual analog scale (VAS) for neck pain, complications, fusion rate, adjacent segment degeneration (ASD), cervical lordosis (CL), and residual segmental mobility were evaluated.

RESULTS

 We enrolled 21 patients. Tantalum and carbon fiber cages were implanted, respectively, in 13 and 8 patients. The mean FU length was 5.76 ± 0.87 years. Mean NDI score was 78.29 ± 9.98% preoperatively and 8.29 ± 1.67% at last FU (p < 0.01), whereas mean VAS score decreased from 7.43 ± 1.14 preoperatively to 0.95 ± 0.95 at last FU (p < 0.01). Complications were one postoperative hematoma, one superficial wound infection, and five cases of postoperative dysphagia (recovered within 3 days). The fusion rate was 90% and ASD was reported in three (14%) cases. The mean CL was 6.33 ± 2.70 degrees preoperatively, 8.19 ± 1.97 degrees 3 months after surgery (p = 0.02), and 7.62 ± 1.96 degrees at latest FU. There was no residual mobility on every operated segment at last FU. The smoking status was an independent risk factor for nonfusion in this case series (p = 0.02).

CONCLUSIONS

 Three-level contiguous ACDF without plating seems to be an effective treatment for cervical DDD. Properly designed comparative clinical trials are needed to further investigate this topic.

Prediction of Worse Functional Status After Surgery for Degenerative Cervical Myelopathy: A Machine Learning Approach

BACKGROUND

Surgical decompression for degenerative cervical myelopathy (DCM) is one of the mainstays of treatment, with generally positive outcomes. However, some patients who undergo surgery for DCM continue to show functional decline.

OBJECTIVE

To use machine learning (ML) algorithms to determine predictors of worsening functional status after surgical intervention for DCM.

METHODS

This is a retrospective analysis of prospectively collected data. A total of 757 patients enrolled in 2 prospective AO Spine clinical studies, who underwent surgical decompression for DCM, were analyzed. The modified Japanese Orthopedic Association (mJOA) score, a marker of functional status, was obtained before and 1 yr postsurgery. The primary outcome measure was the dichotomized change in mJOA at 1 yr according to whether it was negative (worse functional status) or non-negative. After applying an 80:20 training-testing split of the dataset, we trained, optimized, and tested multiple ML algorithms to evaluate algorithm performance and determine predictors of worse mJOA at 1 yr.

RESULTS

The highest-performing ML algorithm was a polynomial support vector machine. This model showed good calibration and discrimination on the testing data, with an area under the receiver operating characteristic curve of 0.834 (accuracy: 74.3%, sensitivity: 88.2%, specificity: 72.4%). Important predictors of functional decline at 1 yr included initial mJOA, male gender, duration of myelopathy, and the presence of comorbidities.

CONCLUSION

The reasons for worse mJOA are frequently multifactorial (eg, adjacent segment degeneration, tandem lumbar stenosis, ongoing neuroinflammatory processes in the cord). This study successfully used ML to predict worse functional status after surgery for DCM and to determine associated predictors.

Inadequate spinal cord expansion in intraoperative ultrasound after decompression may predict neurological recovery of degenerative cervical myelopathy

OBJECTIVE

To compare the neurological recovery between patients with adequate and inadequate immediate spinal cord expansion after sufficient decompression in degenerative cervical myelopathy (DCM).

METHODS

Twenty-seven patients subjected to French-door laminoplasty underwent the guidance of intraoperative ultrasound (IOUS) and were prospectively included. The modified Japanese Orthopedic Association (mJOA) score was evaluated before surgery and at 12 months postoperatively. The maximum spinal cord compression (MSCC) after sufficient decompression was calculated on the IOUS image; patients were divided into adequate (MSCC ≥ 0.95) and inadequate (MSCC < 0.95) expansion groups according to the MSCC. The mJOA score, spinal cord hyperechogenicity, age at surgery, symptom duration, occupational rate of the spinal canal, and the minimum anteroposterior diameter of the spinal cord between the two groups were compared.

RESULTS

Initially, 2 cases showed residual compression on IOUS; after further decompression, all patients acquired sufficient decompression. All patients achieved improvements in mJOA scores with an average recovery rate of 68.6 ± 20.3%. The recovery rate of the mJOA score of the inadequate expansion group was significantly inferior to that of the adequate expansion group (59.2 ± 21.7% versus 76.2 ± 16.2%, p = 0.028). The spinal cord hyperechogenicity was more common in the inadequate expansion group, while the spinal cord anteroposterior diameter of the inadequate expansion group was significantly smaller than that of the adequate expansion group.

CONCLUSIONS

The application of IOUS in French-door laminoplasty could help to confirm sufficient decompression for the treatment of DCM. Inadequate spinal cord expansion after sufficient decompression had the high possibility of predicting less satisfactory neurological recovery of DCM.

KEY POINTS

• The intraoperative ultrasound revealed that not all degenerative cervical myelopathy patients acquired adequate spinal cord expansion after sufficient decompression. • Patients who failed to acquire adequate spinal cord expansion commonly combined with spinal cord hyperechogenicity and trended to achieve less satisfactory neurological recovery after surgical decompression. • Inadequate spinal cord expansion after sufficient decompression had the high possibility of predicting less satisfactory neurological recovery of patients with degenerative cervical myelopathy.

Intensity of Intraoperative Spinal Cord Hyperechogenicity as a Novel Potential Predictive Indicator of Neurological Recovery for Degenerative Cervical Myelopathy

OBJECTIVE

To analyze the correlations between intraoperative ultrasound and MRI metrics of the spinal cord in degenerative cervical myelopathy and identify novel potential predictive ultrasonic indicators of neurological recovery for degenerative cervical myelopathy.

MATERIALS AND METHODS

Twenty-two patients who underwent French-door laminoplasty for multilevel degenerative cervical myelopathy were followed up for 12 months. The Japanese Orthopedic Association (JOA) scores were assessed preoperatively and 12 months postoperatively. Maximum spinal cord compression and compression rates were measured and calculated using both intraoperative ultrasound imaging and preoperative T2-weight (T2W) MRI. Signal change rates of the spinal cord on preoperative T2W MRI and gray value ratios of dorsal and ventral spinal cord hyperechogenicity on intraoperative ultrasound imaging were measured and calculated. Correlations between intraoperative ultrasound metrics, MRI metrics, and the recovery rate JOA scores were analyzed using Spearman correlation analysis.

RESULTS

The postoperative JOA scores improved significantly, with a mean recovery rate of 65.0 ± 20.3% (p < 0.001). No significant correlations were found between the operative ultrasound metrics and MRI metrics. The gray value ratios of the spinal cord hyperechogenicity was negatively correlated with the recovery rate of JOA scores (ρ = -0.638, p = 0.001), while the ventral and dorsal gray value ratios of spinal cord hyperechogenicity were negatively correlated with the recovery rate of JOA-motor scores (ρ = -0.582, p = 0.004) and JOA-sensory scores (ρ = -0.452, p = 0.035), respectively. The dorsal gray value ratio was significantly higher than the ventral gray value ratio (p < 0.001), while the recovery rate of JOA-motor scores was better than that of JOA-sensory scores at 12 months post-surgery (p = 0.028).

CONCLUSION

For degenerative cervical myelopathy, the correlations between intraoperative ultrasound and preoperative T2W MRI metrics were not significant. Gray value ratios of the spinal cord hyperechogenicity and dorsal and ventral spinal cord hyperechogenicity were significantly correlated with neurological recovery at 12 months postoperatively.

Pattern and Rate of Functional Recovery After Surgery for Cervical Spondylotic Myelopathy: Egyptian Prospective Study

OBJECTIVE

To study pattern and rate of neurological functional recovery after surgery for cervical spondylotic myelopathy (CSM).

METHODS

This prospective study comprised 25 patients with CSM who underwent surgical decompression at our institution. Upper limb, lower limb, and sphincter functions were assessed using the modified Japanese Orthopaedic Association score (mJOA). Assessment was done before the operation and at 1 month, 3 months, and 1 year after surgery.

RESULTS

The mJOA score did not significantly increase at 1 month after surgery (P = 0.051); however, increase in mJOA score was statistically significant at 3 and 1 year after surgery (P < 0.001 and P < 0.001, respectively). Upper limb motor dysfunction improved in 65% of patients, lower limb motor dysfunction improved in 52% of patients, upper limb sensory dysfunction improved in 48% of patients, and sphincter dysfunction improved in 14.2% of patients. There was a significant positive correlation between preoperative and postoperative mJOA score at 1 month, 3 months, and 1 year after surgery.

CONCLUSIONS

Minimal improvement occurred in the first month after CSM surgery to reach a peak at 3 months after surgery and steady improvement up to 1 year after surgery. Upper limbs recovered better and earlier than lower limbs and sphincter function. Preoperative severity of CSM is one of the main predictors of postoperative neurological outcome.

Drivers of in-hospital opioid consumption in patients undergoing lumbar fusion surgery

Background

With the current opioid crisis, as many as 38% of patients are still on opioids one year after elective spine surgery. Identifying drivers of in-hospital opioid consumption may decrease subsequent opioid dependence. We aimed to identify the drivers of in-hospital opioid consumption in patients undergoing 1-2-level instrumented lumbar fusions.

Methods

This is a retrospective cohort study. Electronic medical record analysts identified consecutive patients undergoing 1-2 level instrumented lumbar fusions for degenerative lumbar conditions from 2016 to 2018 from a single-center hospital administrative database. Oral, intravenous, and transdermal opioid dose administrations were converted to morphine milligram equivalents (MME). Linear regression analysis was used to determine associations between postoperative day (POD) 4 cumulative in-hospital MMEs and the patients' baseline characteristics including body mass index (BMI), race, American Society of Anesthesiologists (ASA) grade, smoking status, marital status, insurance type, zip code, number of fused levels, approach and preoperative opioid use.

Results

A total of 1,502 patients were included. The mean cumulative MMEs at POD 4 was 251.5. Linear regression analysis yielded four drivers including younger age, preoperative opioid use, current smokers and more levels fused. There were no associations with surgical approach, zip code, ASA grade, marital status, BMI, race or insurance type.

Conclusions

Use of preoperative opioids and smoking are modifiable risk factors for higher in-hospital opioid consumption and can be targets for intervention prior to surgery in order to decrease in-hospital opioid use.

Compressive Cervical Myelopathy in Patients With Demyelinating Disease of the Central Nervous System: Improvement After Surgery Despite a Late Diagnosis

Objective We aimed to assess the impact of surgical intervention on outcome in patients diagnosed with demyelinating disorders and cervical degenerative disease warranting surgical intervention. Methods The records of patients with a diagnosis of a demyelinating disorder of the central nervous system who underwent cervical spine surgery at a single institution from 2016 to 2020 were reviewed. Demyelinating disease included multiple sclerosis (MS), neuromyelitis optica, and transverse myelitis (TM). The dates of initial spine symptom onset, recognition of spinal pathology by the primary provider, referral to spine surgery, and spine surgery procedures were collected. Hospital length of stay (LOS) and postoperative outcomes and complications were recorded. Results A total of 19 patients with a diagnosis of demyelinating disorders underwent cervical spine surgery at our institution. Seventeen patients had MS. The average time interval between a documented diagnosis of myelopathy or radiculopathy and referral to the Spine clinic was 67.95 months (M=40, SD=64.87). Twelve patients had imaging studies depicting degenerative spine disease that would warrant surgical intervention at the time of examination by their primary physician. The average delay for referral to the Spine clinic for these patients was 16.5 months (M=5; SD=25.36). More than 89% of patients experienced significant neurologic improvement postoperatively. Conclusions There is a delay in the recognition of cervical spine disease amenable to a surgical resolution in patients with demyelinating disorders. Surgical treatment can lead to significant clinical improvement in this patient population even if delayed, and likely carries similar risk to that of the general population.

Prediction of outcome following laminoplasty of cervical spondylotic myelopathy: Focus on the minimum clinically important difference

The minimum clinically important difference (MCID) of the Japanese Orthopaedic Association (JOA) score has been reported to be around 2.5 points in cervical myelopathy. This study sought to define significant predictive factors on achieving the MCID following laminoplasty in a large series of patients with cervical spondylotic myelopathy (CSM). A total of 485 consecutive patients with CSM (295 males and 190 females; mean age: 67.0 years; age range: 42-91 years) who underwent laminoplasty were prospectively enrolled. The average postoperative follow-up period was 26.6 months (range: 12-66 months). We calculated the achieved JOA score. The relationships between outcomes and various clinical and imaging predictors including comorbidity and quantitative performance tests were examined. Logistic regression analysis was conducted to identify the predictors correlated with a JOA score of 2.5 points or more. Clinically meaningful gains were exhibited in 299 patients (61.6%) with a JOA score of ≥2.5 points, whereas 186 patients (38.4%) achieved a JOA score of <2.5 points. Univariate logistic regression analysis showed the predictive factors with a shorter duration of CSM symptoms, lower preoperative JOA scores, absence of hypertension, no use of anticoagulant/antiplatelet agents, and nonsmoking status. Multivariate logistic regression analysis determined that the duration of CSM symptoms (odds ratio: 0.771, 95% confidence interval: 0.705-0.844; p < 0.01) was the only significant predictive factor for achieving JOA scores of ≥2.5 points. An important predictor of MCID achievement following laminoplasty was shorter duration of CSM symptoms.

Frailty Is a Better Predictor than Age of Mortality and Perioperative Complications after Surgery for Degenerative Cervical Myelopathy: An Analysis of 41,369 Patients from the NSQIP Database 2010-2018

Background: The ability of frailty compared to age alone to predict adverse events in the surgical management of Degenerative Cervical Myelopathy (DCM) has not been defined in the literature. Methods: 41,369 patients with a diagnosis of DCM undergoing surgery were collected from the National Surgical Quality Improvement Program (NSQIP) Database 2010–2018. Univariate analysis for each measure of frailty (modified frailty index 11- and 5-point; MFI-11, MFI-5), modified Charlson Co-morbidity index and ASA grade) were calculated for the following outcomes: mortality, major complication, unplanned reoperation, unplanned readmission, length of hospital stay, and discharge to a non-home destination. Multivariable modeling of age and frailty with a base model was performed to define the discriminative ability of each measure. Results: Age and frailty have a significant effect on all outcomes, but the MFI-5 has the largest effect size. Increasing frailty correlated significantly with the risk of perioperative adverse events, longer hospital stay, and risk of a non-home discharge destination. Multivariable modeling incorporating MFI-5 with age and the base model had a robust predictive value (0.85). MFI-5 had a high categorical assessment correlation with a MFI-11 of 0.988 (p < 0.001). Conclusions and Relevance: Measures of frailty have a greater effect size and a higher discriminative value to predict adverse events than age alone. MFI-5 categorical assessment is essentially equivalent to the MFI-11 score for DCM patients. A multivariable model using MFI-5 provides an accurate predictive tool that has important clinical applications.

Magnetization Transfer Ratio and Morphometrics of the Spinal Cord Associates with Surgical Recovery in Patients with Degenerative Cervical Myelopathy

OBJECTIVES

We assessed the prognostic value of the preoperative magnetization transfer ratio (MTR) and morphometrics of the spinal cord in patients with degenerative cervical myelopathy (DCM) in a longitudinal cohort study.

METHODS

Thirteen subjects with DCM underwent 3T magnetization transfer imaging. The MTR was calculated for the spinal cord regions and specific white matter tracts. Morphometric measures were extracted. Clinical (modified Japanese Orthopaedics Association [mJOA] and Nurick scale scores) and health-related quality of life scores were assessed before and after cervical decompression surgery. The association between the magnetic resonance imaging (MRI) metrics and postoperative recovery was assessed (Spearman's correlation). Receiver operating characteristics were used to assess the accuracy of MRI metrics in identifying ≥50% recovery in function.

RESULTS

Preoperative anterior cord MTRs were associated with recovery in mJOA scores (ρ = 0.608; P = 0.036; area under the curve [AUC], 0.66). Preoperative lateral cord MTR correlated with the neck disability index (ρ = 0.699; P = 0.011) and pain interference scale (ρ = 0.732; P = 0.007). Preoperative rubrospinal tract MTR was associated with mJOA score recovery (ρ = 0.573; P = 0.041; AUC, 0.86). Preoperative corticospinal tract and reticulospinal MTRs were related to recovery in pain interference scores (ρ = 0.591; P = 0.033; and ρ = 0.583; P = 0.035, respectively). Eccentricity of the cord was associated with Nurick scores (ρ = 0.606; P = 0.028) and mJOA scores (ρ = 0.651; P = 0.025; AUC, 0.92).

CONCLUSIONS

Preoperative MTR and eccentricity measurements of the spinal cord have prognostic value in assessing the response to surgery and recovery in patients with DCM. Advanced MRI and atlas-based postprocessing techniques can inform interventions and advance the healthcare received by patients with DCM.

A partial least squares analysis of functional status, disability, and quality of life after surgical decompression for degenerative cervical myelopathy

Previous studies aimed at identifying predictors of clinical outcomes following surgical decompression for degenerative cervical myelopathy (DCM) are limited by multicollinearity among predictors, whereby the high degree of correlation between covariates precludes detection of potentially significant findings. We apply partial least squares (PLS), a data-driven approach, to model multi-dimensional variance and dissociate patient phenotypes associated with functional, disability, and quality of life (QOL) outcomes in DCM. This was a post-hoc analysis of DCM patients enrolled in the prospective, multi-center AOSpine CSM-NA/CSM-I studies. Baseline clinical covariates evaluated as predictors included demographic (e.g., age, sex), clinical presentation (e.g., signs and symptoms), and treatment (e.g., surgical approach) characteristics. Outcomes evaluated included change in functional status (∆mJOA), disability (∆NDI), and QOL (∆SF-36) at 2 years. PLS was used to derive latent variables (LVs) relating specific clinical covariates with specific outcomes. Statistical significance was estimated using bootstrapping. Four hundred and seventy-eight patients met eligibility criteria. PLS identified 3 significant LVs. LV1 indicated an association between presentation with hand muscle atrophy, treatment by an approach other than laminectomy alone, and greater improvement in physical health-related QOL outcomes (e.g., SF-36 Physical Component Summary). LV2 suggested the presence of comorbidities (respiratory, rheumatologic, psychological) was associated with lesser improvements in functional status post-operatively (i.e., mJOA score). Finally, LV3 reflected an association between more severe myelopathy presenting with gait impairment and poorer mental health-related QOL outcomes (e.g., SF-36 Mental Component Summary). Using PLS, this analysis uncovered several novel insights pertaining to patients undergoing surgical decompression for DCM that warrant further investigation: (1) comorbid status and frailty heavily impact functional outcome; (2) presentation with hand muscle atrophy is associated with better physical QOL outcomes; and (3) more severe myelopathy with gait impairment is associated with poorer mental QOL outcomes.

Study protocol for an observational study of cerebrospinal fluid pressure in patients with degenerative cervical myelopathy undergoing surgical deCOMPression of the spinal CORD: the COMP-CORD study

INTRODUCTION

Degenerative cervical myelopathy (DCM) is a disabling spinal disorder characterised by sensorimotor deficits of upper and lower limbs, neurogenic bladder dysfunction and neuropathic pain. When suspected, cervical MRI helps to reveal spinal cord compression and rules out alternative diagnoses. However, the correlation between radiological findings and symptoms is weak. Cerebrospinal fluid pressure (CSFP) analysis may complement the appreciation of cord compression and be used for intraoperative and postoperative monitorings in patients undergoing surgical decompression.

METHODS AND ANALYSIS

Twenty patients diagnosed with DCM undergoing surgical decompression will receive standardised lumbar CSFP monitoring immediately before, during and 24 hours after operation. Rest (ie, opening pressure, CSF pulsation) and stimulated (ie, Valsalva, Queckenstedt's) CSFP-findings in DCM will be compared with 20 controls and results from CSFP monitoring will be related to clinical and neurophysiological findings. Arterial blood pressure will be recorded perioperatively and postoperatively to calculate spinal cord perfusion pressure and spinal vascular reactivity index. Furthermore, measures of CSFP will be compared with markers of spinal cord compression by means of MR imaging.

ETHICS AND DISSEMINATION

The study protocol conformed to the latest revision of the Declaration of Helsinki and was approved by the local Ethics Committee of the University Hospital of Zurich (KEK-ZH number PB-2016-00623). The main publications from this study will cover the CSFP fluid dynamics and pressure analysis preoperative, perioperative and postoperative correlated with imaging, clinical scores and neurophysiology. Other publications will deal with preoperative and postoperative spinal perfusion. Furthermore, we will disseminate an analysis on waveform morphology and the correlation with blood pressure and ECG. Parts of the data will be used for computational modelling of cervical stenosis.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT02170155).

Zonisamide ameliorates progression of cervical spondylotic myelopathy in a rat model

Cervical spondylotic myelopathy (CSM) is caused by chronic compression of the spinal cord and is the most common cause of myelopathy in adults. No drug is currently available to mitigate CSM. Herein, we made a rat model of CSM by epidurally implanting an expanding water-absorbent polymer underneath the laminae compress the spinal cord. The CSM rats exhibited progressive motor impairments recapitulating human CSM. CSM rats had loss of spinal motor neurons, and increased lipid peroxidation in the spinal cord. Zonisamide (ZNS) is clinically used for epilepsy and Parkinson's disease. We previously reported that ZNS protected primary spinal motor neurons against oxidative stress. We thus examined the effects of ZNS on our rat CSM model. CSM rats with daily intragastric administration of 0.5% methylcellulose (n = 11) and ZNS (30 mg/kg/day) in 0.5% methylcellulose (n = 11). Oral administration of ZNS ameliorated the progression of motor impairments, spared the number of spinal motor neurons, and preserved myelination of the pyramidal tracts. In addition, ZNS increased gene expressions of cystine/glutamate exchange transporter (xCT) and metallothionein 2A in the spinal cord in CSM rats, and also in the primary astrocytes. ZNS increased the glutathione (GSH) level in the spinal motor neurons of CSM rats. ZNS potentially ameliorates loss of the spinal motor neurons and demyelination of the pyramidal tracts in patients with CSM.

Transthoracic microsurgical anterior decompression without fusion for ossification of the posterior longitudinal ligament in the thoracic spine

OBJECTIVE

The authors aimed to analyze outcomes following transthoracic microsurgical anterior decompression of thoracic ossification of the posterior longitudinal ligament (T-OPLL), which was causing myelopathy, and determine the predictive factors for surgical outcomes.

METHODS

Patients who underwent transthoracic microsurgical anterior decompression without fusion for the treatment of T-OPLL from December 2014 to May 2019 were included. Demographic, radiological, and perioperative data and clinical outcomes of 35 patients were analyzed. The modified Japanese Orthopaedic Association (mJOA) score and recovery rate were used to evaluate functional outcomes.

RESULTS

A total of 35 consecutive patients (8 men and 27 women; mean age 52.2 ± 10.8 years) were enrolled in this study, and the mean follow-up period was 65.5 ± 51.9 months. The mean mJOA score significantly improved after surgery (5.9 ± 1.8 vs 8.3 ± 1.5, p < 0.001), with a mean recovery rate of 47.7% ± 24.5%. The visual analog scale (VAS) score significantly improved after surgery (7.3 ± 1.3 vs 4.3 ± 0.7, p < 0.001). The outcome was excellent in 4 patients (11.4%), good in 21 patients (60.0%), fair in 4 patients (11.4%), unchanged in 5 patients (14.3%), and worsened in 1 patient (2.9%). There were 12 cases of CSF leakage, 1 case of epidural hematoma, 1 case of pleural effusion, and 1 case of pneumothorax. Age, preoperative kyphotic angle, anteroposterior length of T-OPLL at the maximally affected level, and mass occupying rate were identified as predictors associated with postoperative outcome. A multivariate regression analysis revealed that age and preoperative kyphotic angle were independent risk factors for postoperative outcomes.

CONCLUSIONS

Transthoracic microsurgical anterior decompression without fusion achieved favorable clinical and radiological outcomes for treating T-OPLL with myelopathy. Patient age and preoperative kyphotic angle were independent risk factors for lower recovery rate.

Short-term predictive potential of quantitative assessment of spinal cord impairment in patients undergoing French-door Laminoplasty for degenerative cervical myelopathy: preliminary results of an exploratory study exploiting intraoperative ultrasound data

BACKGROUND

To study the correlation of neurological function in degenerative cervical myelopathy (DCM) patients with quantitative assessment of spinal cord compression and impairment by intraoperative ultrasound imaging (IOUSI).

METHODS

Twenty-three patients who underwent French-Door laminoplasty for multilevel DCM were followed for 6 months. Modified Japanese Orthopaedic Association (mJOA) score and cervical MRI were assessed before surgery and at postoperative 6 months. IOUS, used to guide decompression, were recorded. The anteroposterior diameter (APD) and the gray values of the IOUSI hyperechogenicity of the midsagittal IOUSI at the narrowest level and at the lesion-free level, and the APD and traverse diameter at the traverse maximum compression level of IOUSI were measured. Maximum spinal cord compression (MSCC), compression rate (CR), and IOUSI gray value ratio (R_gray) were calculated. The appearance of preoperative T2W MRI increased signal intensity (ISI), and the signal change rate (SCR) on postoperative T2W MRI of 9 patients were also measured and calculated, and compared with that of IOUSI hyperechogenicity.

RESULTS

Average mJOA score increased significantly from 11.57 ± 2.67 before surgery to 15.39 ± 1.50 at 6 months after surgery, with an average recovery rate (RR) of 71.11 ± 22.81%. The difference between the appearance of preoperative T2W MRI ISI and IOUSI hyperechogenicity was not significant. Spearman correlation analysis found that the IOUSI R_gray were negatively correlated with the RR of mJOA score with a coefficient of - 0.77, and the IOUSI R_gray was not correlated with the postoperative MRI SCR.

CONCLUSIONS

In DCM patients, the gray values of IOUSI can be measured accurately. The IOUSI R_gray correlated with postoperative neurological recovery significantly.

Cervical Decompression for Myelopathy in a Resource-Poor Region: Initial Experience

BACKGROUND

The aim of this study was to document the initial experience and challenges of cervical decompression in a resource-poor region.

METHODS

Forty-three patients with cervical myelopathy who had surgery were included in the study. Details including evaluations pre- and postoperative (at 6 weeks and 6 months) using the Nurick score were recorded prospectively. Details of surgery were also documented.

RESULTS

The mean age at surgery was 58.0 years. There were 37 men and 6 women. Surgeries performed were anterior cervical decompression and fusion (51.2%), cervical laminectomy (32.6%), corpectomy and occipitocervical fixation (2.3% each), and decompression with lateral mass fixation (11.6%). Four patients presented within 3 months of onset of symptoms (early), whereas 39 after 3 months (late). The Nurick grade significantly improved in 41 patients (97.6%) following surgery (P < 0.001). The average Nurick preoperative score was 3.2, and postoperative it was 2.12 and 1.14 at 6 weeks and 6 months, respectively. In the early presentation group, scores improved from an average preoperative of 2.5-0.5 at 6 months, whereas in the late presentation group, score improved from an average of 3.3 preoperative to 1.2 at 6 months postoperative.

CONCLUSIONS

Despite the challenges of poverty, late presentation, and lack of basic standard instruments and equipment, patients with cervical myelopathy in the resource-poor setting had outcomes similar to other well-established centers after surgical decompression. We infer that challenges in setting up a spine unit in a resource-poor region can be circumvented safely.

Degenerative Cervical Myelopathy: Review of Surgical Outcome Predictors and Need for Multimodal Approach

Degenerative cervical myelopathy is the most common cause of spinal cord injury in the elderly population in the developed world, and it significantly affects the quality of life of patients and their caregivers. Surgery remains the only treatment option able to halt disease progression and provide neurological recovery for most patients. Although it has remained challenging to predict exactly who will experience improvement after surgery, increasingly it has been shown that clinical, imaging, and electrophysiological factors can predict, with relatively good capacity, those more likely to benefit. Clinically, the baseline neurological impairment appears to be strongly related to the outcome, and the magnetic resonance imaging findings of T1-weighted hypointensity and the length of T2-weighted hyperintensity appear to be the most prognostic. In this context, electrophysiology findings (both motor and sensory evoked potentials) have shown some predictive capacity. However, large studies are lacking. Although multivariate models have been conducted using clinical and magnetic resonance imaging data, no multimodal prediction models are available that encompass the predictive capacity of clinical, imaging, and electrophysiological data. In the present review, we examined the rationale for clinical, imaging, and electrophysiological usage in clinical practice and discussed a model of multimodal assessment for the management of degenerative cervical myelopathy.