Pathophysiology and natural history of cervical spondylotic myelopathy

Recent advances in the management of cervical spondylotic myelopathy: bibliometric analysis and surgical perspectives

OBJECTIVE

Cervical spondylotic myelopathy (CSM) has become a prevalent cause of spinal cord dysfunction among the aging population worldwide. Although great strides have been made in spine surgery in past decades, the optimal timing and surgical strategy to treat CSM have remained controversial. In this article the authors aimed to analyze the current trends in studies of CSM and to summarize the recent advances of surgical techniques in its treatment.

METHODS

The PubMed database was searched using the keywords pertaining to CSM in human studies that were published between 1975 and 2018. Analyses of both the bibliometrics and contents, including the types of papers, authors, affiliations and countries, number of patients, and the surgical approaches were conducted. A systematic review of the literature was also performed with emphasis on the diagnosis and treatment of mild CSM.

RESULTS

A total of 1008 papers published during the span of 44 years were analyzed. These CSM studies mainly focused on the natural history, diagnosis, and treatment, and only a few prospective randomized trials were reported. For the authors and affiliations, there was a shift of clustering of papers toward Asian countries in the past decades. Regarding the treatment for CSM, there was an exponential growth of surgical series published, and there was a trend toward slightly more anterior than posterior approaches through the past decade. Patients with CSM had increased risks of neurological deterioration or spinal cord injury with nonoperative management. Because surgery might reduce the risks, and early surgery was likely to be correlated with better outcomes, there was a trend toward attention to mildly symptomatic CSM.

CONCLUSIONS

There is emerging enthusiasm for research on CSM worldwide, with more publications originating in Asian countries over the past few decades. The surgical management of CSM is evolving continuously toward early and anterior approaches. More prospective investigations on the optimal timing and choices of surgery are therefore needed.

A Systematic Review of Definitions for Neurological Complications and Disease Progression in Patients Treated Surgically for Degenerative Cervical Myelopathy

STUDY DESIGN

Systematic review.

OBJECTIVE

This review aims to (1) outline how neurological complications and disease progression are defined in the literature and (2) evaluate the quality of definitions using a novel four-point rating system.

SUMMARY OF BACKGROUND DATA

Degenerative cervical myelopathy (DCM) is a progressive, degenerative spine disease that is often treated surgically. Although uncommon, surgical decompression can be associated with neurological complications, such as C5 nerve root palsy, perioperative worsening of myelopathy, and longer-term deterioration. Unfortunately, important questions surrounding these complications cannot be fully addressed due to the heterogeneity in definitions used across studies. Given this variability, there is a pressing need to develop guidelines for the reporting of surgical complications in order to accurately evaluate the safety of surgical procedures.

METHODS

An electronic database search was conducted in MEDLINE, MEDLINE in Process, EMBASE and Cochrane Central Register of Controlled Trials for studies that reported on complications related to DCM surgery and included at least 10 surgically treated patients. Data extracted included study design, surgical details, as well as definitions and rates of surgical complications. A four-point rating scale was developed to assess definition quality for each complication.

RESULTS

Our search yielded 2673 unique citations, 42 of which met eligibility criteria and were summarized in this review. Defined complications included neurological deterioration, late onset deterioration, perioperative worsening of myelopathy, C5 palsy, nerve root or upper limb palsy or radiculopathy, surgery failure, inadequate decompression and progression of ossified lesions. Reported rates of these complications varied substantially, especially those for neurological deterioration (0.2%-33.3%) and progression of ossified lesions (0.0%-86.7%).

CONCLUSION

Reported incidences of various complications vary widely in DCM surgery, especially for neurological deterioration and progression of ossified lesions. This summary serves as a first step for standardizing definitions and developing guidelines for accurately reporting surgical complications.

LEVEL OF EVIDENCE

2.

Degenerative Cervical Myelopathy; A Review of the Latest Advances and Future Directions in Management

The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical technology to ensure the best outcome is achieved for each individual patient.

Risk Factors for Rapidly Progressive Neurological Deterioration in Cervical Spondylotic Myelopathy

STUDY DESIGN

A retrospective single-center study.

OBJECTIVE

This study sought to clarify the risk factors and to evaluate the surgical outcome in patients with rapidly progressive cervical spondylotic myelopathy (rp-CSM).

SUMMARY OF BACKGROUND DATA

CSM is a degenerative spine disease presenting a slow development of myelopathy. Some patients, however, show rapidly progressive neurological deterioration (especially gait disturbances) without any trauma. At present, there is little information about this condition.

METHODS

We studied 71 consecutive CSM patients (52 men, 19 women) with a mean age of 67.1 years, and the follow-up period was 1 year. Patients were divided into two groups: rp-CSM and chronic-CSM (c-CSM) groups. The Japanese Orthopaedic Association score and various clinical differences, including age, sex, comorbidity, the waiting period from symptomatic onset to surgery, cervical range of motion, and intramedullary MR T2-hyperintensity were analyzed, and independent risk factors were determined using a logistic regression analysis.

RESULTS

Eighteen of 71 patients (25.4%) were diagnosed with rp-CSM. There were no significant differences between the two groups with regard to age, sex, or cervical range of motion. In the rp-CSM group, the preoperative upper/lower extremities and bladder functions were worse, and the waiting period for surgery was shorter (rp-CSM 1.2 mo, c-CSM 25.7 mo). Patients with rp-CSM had a history of cardiovascular event (CVE) (rp-CSM 44.4%, c-CSM 15.1%) and presented with MR T2-hyperintensity (rp-CSM 94.4%, c-CSM 58.5%), especially at the C4/5 disc level. Independent risk factors were a history of CVE (odds ratio = 4.7) and MR T2-hyperintensity (odds ratio  = 12.5). The rp-CSM group showed a better neurological recovery after decompression surgery (the Japanese Orthopaedic Association recovery rate: rp-CSM 64.5%, c-CSM 40.7%).

CONCLUSION

A history of CVE and MR T2-hyperintensity were risk factors for rp-CSM. Despite rapid neurological deterioration, rp-CSM patients showed a good neurological recovery after surgery, and thus indicating that rp-CSM is a reversible condition.

LEVEL OF EVIDENCE

4.

Effect of Modified Japanese Orthopedic Association Severity Classifications on Satisfaction With Outcomes 12 Months After Elective Surgery for Cervical Spine Myelopathy

STUDY DESIGN

This study retrospectively analyzes prospectively collected data.

OBJECTIVE

Here, we aim to determine the influence of preoperative and 12-month modified Japanese Orthopedic Association (mJOA) on satisfaction and understand the change in mJOA severity classification after surgical management of degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

DCM is a progressive degenerative spine disease resulting from cervical cord compression. The natural progression of DCM is variable; some patients experience periods of stability, while others rapidly deteriorate following disease onset. The mJOA is commonly used to grade and categorize myelopathy symptoms, but its association with postoperative satisfaction has not been previously explored.

METHODS

The quality and outcomes database (QOD) was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9 to 13), or severe (<9) categories on the mJOA scores. A McNemar-Bowker test was used to assess whether a significant proportion of patients changed mJOA category between preoperative and 12 months postoperative. A multivariable proportional odds ordinal logistic regression model was fitted with 12-month satisfaction as the outcome of interest.

RESULTS

We identified 1963 patients who underwent elective surgery for DCM and completed 12-months follow-ups. Comparing mJOA severity level preoperatively and at 12 months revealed that 55% remained in the same category, 37% improved, and 7% moved to a worse category. After adjusting for baseline and surgery-specific variables, the 12-month mJOA category had the highest impact on patient satisfaction (P < 0.001).

CONCLUSION

Patient satisfaction is an indispensable tool for measuring quality of care after spine surgery. In this sample, 12-month mJOA category, regardless of preop mJOA, was significantly correlated with satisfaction. Given these findings, it is important to advise patients of the probability that surgery will change their mJOA severity classification and the changes required to achieve postoperative satisfaction.

LEVEL OF EVIDENCE

3.

The correlation between hypoxia-inducible factor-1α, matrix metalloproteinase-9 and functional recovery following chronic spinal cord compression

The molecular mechanisms underlying cervical spondylotic myelopathy (CSM) are poorly understood. To assess the correlation between HIF-1α, MMP-9 and functional recovery following chronic cervical spinal cord compression (CSCI). Rats in the sham group underwent C5 semi-laminectomy, while a water-absorbable polyurethane polymer was implanted into the C6 epidural space in the chronic CSCI group. Basso, Beattie and Bresnahan score and somatosensory evoked potentials were used to evaluate neurological function. Hematoxylin and eosin staining was performed to assess pathological changes in the spinal cord, while immunohistochemical analysis was used to examine HIF-1α and MMP-9 expression on days 7, 28, 42 and 70 post-surgery. Normal rats were only used for HE staining. The BBB score was significantly reduced on day 28 following CSCI, while SEPs exhibited decreased amplitude and increased latency. In chronic CSCI group, the BBB score and SEPs significantly improved on day 70 compared with day 28. HE staining revealed different level of spinal cord edema after chronic CSCI. Compared with the sham group, immunohistochemical analyses revealed that HIF-1α- and MMP-9-positive cells were increased on day 7 and peaked on day 28. HIF-1α and MMP-9 expression were demonstrated to be significantly positively correlated, whereas HIF-1α expression and BBB score were significantly negatively correlated, as well MMP-9 expression and BBB score. HIF-1α and MMP-9 expression are increased following chronic spinal cord compression and are positively correlated with one another. Decreased expression of HIF-1α and MMP-9 may contribute to functional recovery following CSCI. This expression pattern of HIF-1α and MMP-9 may give a new perspective on the molecular mechanisms of CSM.

The effect of dural release on extended laminoplasty for the treatment of multi-level cervical myelopathy

Objective

The effects of dural release on extended laminoplasty for the treatment of multi-level cervical myelopathy were explored and discussed.

Method

Patients, who underwent extended laminoplasty combined with dural release for the treatment of multi-level cervical myelopathy (35 cases, group A), were compared with patients who underwent simple extended laminoplasty (38 cases, group B). The JOA score, improvement rate, VAS score, distance of retroposition of the spinal cord, cervical lordosis were compared between the two groups.

Results

Dural laceration occurred to five patients during surgery, three in group A and two in group B; cerebrospinal fluid leakage occurred to five patients, three in group A and two in group B. All patients were followed up for 10 to 48 months (mean 20.3 months). JOA scores and VAS scores in the last follow up period were significantly improved in the two groups than preoperative scores (p < 0.05). The improvement rate and JOA scores in group A were significantly higher than group B, while VAS scores in group A were significantly lower than group B (p < 0.05). There were no significant differences in cervical lordosis in the two groups in the last follow up (p > 0.05), and the distance of retroposition of the spinal cord in group A was higher than B (p < 0.05). No shut-up of the ‘door’ of vertebral lamina occurred in the period of follow-up.

Conclusion

Dural release on extended laminoplasty can achieve retroposition of the spinal cord for multi-level cervical myelopathy, which is more effective than simple extended laminoplasty.

Using a machine learning approach to predict outcome after surgery for degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is a spinal cord condition that results in progressive non-traumatic compression of the cervical spinal cord. Spine surgeons must consider a large quantity of information relating to disease presentation, imaging features, and patient characteristics to determine if a patient will benefit from surgery for DCM. We applied a supervised machine learning approach to develop a classification model to predict individual patient outcome after surgery for DCM. Patients undergoing surgery for DCM as a part of the AOSpine CSM-NA or CSM-I prospective, multi-centre studies were included in the analysis. Out of 757 patients 605, 583, and 539 patients had complete follow-up information at 6, 12, and 24 months respectively and were included in the analysis. The primary outcome was improvement in the SF-6D quality of life indicator score by the minimum clinically important difference (MCID). The secondary outcome was improvement in the modified Japanese Orthopedic Association (mJOA) score by the MCID. Predictor variables reflected information about pre-operative disease severity, disease presentation, patient demographics, and comorbidities. A machine learning approach of feature engineering, data pre-processing, and model optimization was used to create the most accurate predictive model of outcome after surgery for DCM. Following data pre-processing 48, 108, and 101 features were chosen for model training at 6, 12, and 24 months respectively. The best performing predictive model used a random forest structure and had an average area under the curve (AUC) of 0.70, classification accuracy of 77%, and sensitivity of 78% when evaluated on a testing cohort that was not used for model training. Worse pre-operative disease severity, longer duration of DCM symptoms, older age, higher body weight, and current smoking status were associated with worse surgical outcomes. We developed a model that predicted positive surgical outcome for DCM with good accuracy at the individual patient level on an independent testing cohort. Our analysis demonstrates the applicability of machine-learning to predictive modeling in spine surgery.

Comparison of Health-related Quality of Life Between Double-door Laminoplasty and Selective Laminoplasty for Degenerative Cervical Myelopathy, With a Minimum Follow-up of 5 Years

STUDY DESIGN

A retrospective analysis of prospectively collected multicenter observational data.

OBJECTIVE

The aim of this study was to compare the health-related quality of life (HR-QOL) of double-door laminoplasty (DDL) and selective laminoplasty (SL) in patients with degenerative cervical myelopathy (DCM) in two institutions, with a minimum follow-up of 5 years.

SUMMARY OF BACKGROUND DATA

No study has compared DDL and SL regarding postoperative HR-QOL with a follow-up of more than 5 years.

METHODS

One-hundred ninety patients who underwent DDL (n = 77) or SL (n = 113) participated in this study. Short-form 36 (SF-36), Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), Neck Disability Index (NDI), and visual analog scale (VAS) values were compared between the groups.

RESULTS

Thirty-seven DDL and 52 SL patients were evaluated. The mean follow-up period was 8 years and the follow-up rate was 46.8%. No significant differences were found regarding age and JOA score at baseline. At the follow-up, there were no significant differences in SF-36, JOACMEQ, and VAS score, while the NDI score for headache and sleeping were higher in the SL group. After dividing the SL group into short and long SL subgroups, the long SL subgroup showed a significantly lower score in bodily pain in SF-36, lower and bladder function in JOACMEQ, and pain intensity, personal care, headaches, and sleeping in NDI compared with the other groups.

CONCLUSION

No significant differences were found in SF-36, JOA score, and NDI, except for the NDI subscale of headache and sleeping. The subgroup analysis showed that the long SL group showed a decreased QOL compared with the short SL and DDL groups.

LEVEL OF EVIDENCE

3.

Clinical comparison between simple laminectomy and laminectomy plus posterior instrumentation in surgical treatment of cervical myelopathy

BACKGROUND

Posterior stabilization in patients treated with laminectomy for spondylotic cervical myelopathy is still a debate. Despite both being reported in literature by several authors, some controversies still exist. The aim of this study is to compare clinical and radiological outcomes in patients treated with laminectomy or laminectomy with posterior stabilization.

MATERIAL AND METHODS

We retrospectively evaluated 42 patients affected by cervical myelopathy (mean age 70.43 ± 5.03 years), 19 treated with laminectomy (group A) and 23 with laminectomy and posterior instrumentation (group B). Neurological status was assessed with Nurick scale, pain with VAS and radiological parameters with C2-C7 SVA, T1 slope and C2-C7 lordosis, clinical function with modified Japanese Orthopaedic Association score (JOA). Also, surgery time and blood loss were recorded. Student's t test was used for continuous variables, while Kruskal-Wallis test was used for categorical values.

RESULTS

No differences were found in postoperative Nurick scale (p = 0.587), VAS (p = 0.62), mJOA (p = 0.197) and T1 slope (p = 0.559), while laminectomy with fusion showed better postoperative cervical lordosis (p = 0.007) and C2-C7 SVA (p < 0.00001), but higher blood loss (p < 0.00001) and surgical time (p < 0.00001). Both groups showed better Nurick scale (p = 0.00017 for group A and p = 0.00081 for group B), VAS (p = 0.02 for group A and p = 0.046 for group B) and mJOA (p < 0.00001 for both groups) than preoperative values.

CONCLUSIONS

Both treatments are a valuable choice, offering some benefits and disadvantages against each other. Each procedure must be carefully evaluated on the basis of patients' general status, preoperative pain, signs of instability and potential benefits from cervical alignment correction.

Role of Subaxial Spinal and Atlantoaxial Instability in Multisegmental Cervical Spondylotic Myelopathy

AIM

In this paper the role of atlantoaxial and multilevel subaxial spinal instability as the primary nodal point of the pathogenesis of degenerative cervical spinal disease-related myelopathy, and the focus of surgical treatment for it, is evaluated.

MATERIALS AND METHODS

The series analyses the treatment of 73 patients with single or multilevel degenerative cervical spinal disease by fixation of the involved spinal segment(s) alone, aimed at arthrodesis. No bone decompression or disc/osteophyte resection was done. In 23 patients, the atlantoaxial joint was included in the spinal fixation, as atlantoaxial instability was identified by facetal malalignment on imaging or by observations on direct bone manipulation during surgery. There were 70 males and 3 females. The ages of the patients ranged from 35 to 76 years (average 57 years). The transarticular screw method was deployed for subaxial spinal fixation and a lateral mass plate/rod and screw technique was used for atlantoaxial fixation.

RESULTS

During the follow-up period, which ranged from 3 to 42 months (average 27 months), all patients improved in terms of their clinical symptoms. There were no surgery- or implant-related complications.

CONCLUSION

Atlantoaxial joint instability is frequently associated with subaxial multilevel spinal instability in degenerative spinal disease. Fixation of the spinal segments provides a safe, effective and rational treatment for single or multilevel spinal degeneration.

Assessment of degenerative cervical myelopathy differs between specialists and may influence time to diagnosis and clinical outcomes

INTRODUCTION

Degenerative Cervical Myelopathy [DCM] often presents with non-specific symptoms and signs. It progresses insidiously and leads to permanent neurological dysfunction. Decompressive surgery can halt disease progression, however significant delays in diagnosis result in increased disability and limit recovery. The nature of early DCM symptoms is unknown, moreover it has been suggested incomplete examination contributes to missed diagnosis. This study examines how DCM is currently assessed, if assessment differs between stages of healthcare, and whether this influences patient management.

STUDY DESIGN

Retrospective cohort study.

METHODS

Cervical MRI scans (N = 1123) at a tertiary neurosciences center, over a single year, were screened for patients with DCM (N = 43). Signs, symptoms, and disease severity of DCM were extracted from patient records. Patients were considered at 3 phases of clinical assessment: primary care, secondary care, and surgical assessment.

RESULTS

Upper limb paraesthesia and urinary dysfunction were consistently the most and least prevalent symptoms respectively. Differences between assessing clinicians were present in the reporting of: limb pain (p<0.005), objective limb weakness (p = 0.01), hyperreflexia (p<0.005), Hoffmann reflex (p<0.005), extensor plantar reflex (p = 0.007), and lower limb spasticity (p<0.005). Pathological reflexes were least frequently assessed by primary care doctors.

CONCLUSION

DCM assessment varies significantly between assessors. Reporting of key features of DCM is especially low in primary care. Incomplete assessment may hinder early diagnosis and referral to spinal surgery.

3-dimensional printing for anterior cervical surgery: a review

Age-related degenerative changes and non-spondylotic pathologies of the cervical spine such as trauma and tumor can lead to compression of neurological structures and result in substantial alteration of the structural anatomy. The end-goal of surgical intervention is to decompress the neural structures which can be achieved via an anterior or a posterior approach, and stabilization of segments to restore stability and alignment. Three-dimensional printing (3DP or Additive Manufacturing) has been applied to the field of medicine, in particular orthopedics and neurosurgery. Coupled with advances of medical imaging such as computed tomography (CT) scans and magnetic resonance imaging (MRI), accurate 3D models of patient anatomy can be produced, and patient-specific implants (PSIs) for complex anatomical reconstruction have all been applied with positive outcomes. 3D printed implants have been applied in particular to the cervical spine predominantly due to the complex and relatively small osteological anatomy and the proximity of important neurovascular structures to the surgical sites. The purpose of this review is to evaluate the current application of 3DP for cervical spinal implants. This includes a review on the available literature on 3D printed PSIs and current available 3D printed "off-the-shelf" (OTS) implants (3D-OTS). Suitable materials for 3DP of spinal implants and the future prospect of cervical implants will be discussed. The review will be concluded with a suggested guide for carrying future studies to evaluate the efficacy and safety of 3DP for cervical spinal implants.

Treatment of Cervical Myelopathy: Long-term Outcomes of Arthroplasty for Myelopathy Versus Radiculopathy, And Arthroplasty Versus Arthrodesis for Myelopathy

STUDY DESIGN

Analysis of 2- and 7-year outcomes from a clinical trial comparing 2-level cervical disk arthroplasty (CDA) to anterior cervical discectomy and fusion (ACDF) in 287 patients with radiculopathy alone, and 110 patients with myelopathy alone or myelopathy with radiculopathy.

OBJECTIVE

To compare the long-term safety and effectiveness of CDA for myelopathy versus radiculopathy.

SUMMARY OF BACKGROUND DATA

CDA for myelopathy is safe and effective in short term.

MATERIALS AND METHODS

We analyzed Neck Disability Index (NDI), neck/arm pain, SF-36, neurological status, adverse events (AEs), and secondary surgeries at index and adjacent levels.

RESULTS

All groups improved significantly for NDI, neck/arm pain, and physical component summary (PCS) scores from preoperative to postoperative. CDA Myelopathy versus CDA Radiculopathy: 2- and 7-year improvements were not significantly different. The 7-year score improvements for CDA Myelopathy and CDA Radiculopathy were: NDI (37.8 vs. 35.8, P=0.352), neck pain (12.0 vs. 12.1, P=0.477), arm pain (11.6 vs. 9.6, P=0.480), and PCS (14.1 vs. 13.7, P=0.863). The 2 groups had similar proportions of patients who maintained or improved their neurological status (87.2% vs. 93.5%, P=0.218), similar rates of serious AEs (54.5% vs. 57.5%, P=0.291) and similar rates of secondary surgeries at index (3.7% vs. 4.4%, P=0.839) and adjacent levels (3.7% vs. 7.6%, P=0.367). CDA Myelopathy versus ACDF myelopathy: 2 and 7-year improvements were not significantly different. The 7-year CDA and ACDF score improvements were: NDI (37.8 vs. 31.1, P=0.147), neck pain (12.0 vs. 10.4, P=0.337), arm pain (11.6 vs. 11.4, P=0.791), and PCS (14.1 vs. 11.2, P=0.363). The 2 groups had statistically similar proportions who maintained or improved their neurological status (87.2% vs. 96.2%, P=0.409), statistically similar overall rates of secondary surgeries at the index levels (3.7% vs. 9.4%, P=0.374), and statistically similar rates of secondary surgeries at adjacent levels (3.7% vs. 15.4%, P=0.088). CDA group demonstrated lower rates of serious AEs than ACDF (54.5% vs. 65.9%, P=0.019).

CONCLUSIONS

CDA for myelopathy is a safe and effective long-term treatment.

Association of VDR-FokI and VDBP-Thr420Lys polymorphisms with cervical spondylotic myelopathy: A case-control study in the population of China

BACKGROUND

Cervical spondylotic myelopathy (CSM), a common degenerative disorder, is characterized by chronic progressive compression of the cervical spinal cord. The present case-control study aimed to explore the potential role of VDR-FokI and VDBP-Thr420Lys polymorphisms in the susceptibility to CSM in the Chinese population.

METHODS

The study enrolled 318 CSM patients and 282 healthy individuals whose clinical data were retrospectively analyzed. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to genotype VDR-FokI and VDBP-Thr420Lys polymorphisms. The severity of CSM was assessed using the Japanese Orthopaedic Association (JOA) score with magnetic resonance imaging (MRI) of cervical vertebra. A nonconditional binary logistic regression model was conducted for assessing the risk factors of CSM.

RESULTS

Patients in the CSM group had longer time duration to bend over desk working than the control group. The ff genotype and f allele frequency of VDR-FokI were elevated in CSM patients. Elevated Ff + ff genotype and f allele frequency of VDR-FokI might increase the risk of CSM. The VDR-FokI polymorphism was associated with nucleus pulposus capillary invasion, necrosis, hyaline degeneration and fibrosis, genesis and hyperplasia of cartilage-like cells, and fibrocyst in the fibrous ring. The VDR-FokI and VDBP-Thr420Lys genotypes conformed to Hardy-Weinberg equilibrium which showed that VDR-FokI and VDBP-Thr420Lys had group representation characteristics.

CONCLUSION

Binary logistic regression analysis confirmed that VDR-FokI polymorphism and the time to bend over desk working were risk factors of CSM. Our results indicate that VDR-FokI polymorphism may be closely associated with the risk of CSM.

Is Preoperative Duration of Symptoms a Significant Predictor of Functional Outcomes in Patients Undergoing Surgery for the Treatment of Degenerative Cervical Myelopathy?

BACKGROUND

Preoperative duration of symptoms may significantly impact outcomes in patients treated surgically for degenerative cervical myelopathy (DCM).

OBJECTIVE

To (i) analyze whether duration of symptoms is associated with preoperative functional impairment, disability, and quality of life and (ii) determine the optimal timing for decompressive surgery.

METHODS

Patients with DCM were prospectively enrolled in either the AOSpine North American or International study at 26 global sites (n = 757). Postoperative functional impairment was evaluated at 1-yr using the modified Japanese Orthopaedic Association (mJOA) score. Change scores between baseline and 1-yr were computed for the mJOA. Duration of symptoms was dichotomized into a “short” and “long” group at several cut-offs. Analysis of covariance was used to evaluate differences in change scores on the mJOA between duration of symptoms groups in 4-mo increments.

RESULTS

Our cohort consisted of 424 men and 255 women, with a mean duration of symptoms of 26.1 ± 36.4 mo (0.25-252 mo). Duration of symptoms was not correlated with preoperative mJOA, Nurick, Neck Disability Index, or Short-Form (SF)-36 Physical and Mental Component Scores. Patients with a duration of symptoms shorter than 4 mo had significantly better functional outcomes on the mJOA than patients with a longer duration of symptoms (>4 mo). Thirty-two months was also a significant cut-off.

CONCLUSION

Patients who are operated on within 4 mo of symptom presentation have better mJOA outcomes than those treated after 4 mo. It is recommended that patients with DCM are diagnosed in a timely fashion and managed appropriately.

Impact of global spine balance and cervical regional alignment on determination of postoperative cervical alignment after laminoplasty

The aim of this study is to analyze the combined impact of preoperative T1 slope (T1S) and C2-C7 sagittal vertical axis (C2-C7 SVA) on determination of cervical alignment after laminoplasty.Forty patients undergoing laminoplasty for cervical spondylotic myelopathy (CSM) with more than 2 years follow-up were enrolled. Three parameters, including cervical lordosis, T1S, and C2-C7 SVA, were measured by preoperative and postoperative radiographs. Receiver operating characteristics (ROC) curve analysis was used to determine the optimal cut-off values of preoperative T1S and C2-C7 SVA for predicting postoperative loss of cervical lordosis. Patients were classified into 4 categories based on cut-off values of preoperative T1S and C2-C7 SVA. The primary outcome was postoperative C2-C7 SVA. Change in radiographic parameters between 4 groups were compared and analyzed.Optimal cut-off values for predicting loss of cervical lordosis were T1S of 20 degrees and C2-C7 SVA of 22 mm. Patients with small C2-C7 SVA, no matter what the value of T1S, got slight loss of cervical lordosis and increase in C2-C7 SVA. Patients with low T1S and large SVA (T1 ≤20° and SVA >22 mm) got postoperative correction of kyphosis and decrease of C2-C7 SVA. However, patients with high T1S and large SVA (T1 >20° and SVA >22 mm) got mean postoperative C2-C7 SVA value of 37.06 mm, close to the threshold value of 40 mm.Determination of cervical alignment after laminoplasty relies on the equilibrium between destruction of cervical structure, kyphotic force, and adaptive compensation of whole spine, lordotic force. Lower T1S means bigger compensatory ability to adjust different severity of cervical sagittal malalignment, and vice versa.

The Impact of Comorbid Mental Health Disorders on Complications Following Cervical Spine Surgery With Minimum 2-Year Surveillance

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To improve understanding of the impact of comorbid mental health disorders (MHDs) on long-term outcomes following cervical spinal fusion in cervical radiculopathy (CR) or cervical myelopathy (CM) patients.

SUMMARY OF BACKGROUND DATA

Subsets of patients with CR and CM have MHDs, and their impact on surgical complications is poorly understood.

METHODS

Patients admitted from 2009 to 2013 with CR or CM diagnoses who underwent cervical surgery with minimum 2-year surveillance were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System. Patients with a comorbid MHD were compared against those without (no-MHD). Univariate analysis compared demographics, complications, readmissions, and revisions between MHD and no-MHD cohorts. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: age, sex, Charlson/Deyo score, and surgical approach).

RESULTS

A total of 20,342 patients (MHD: n = 4819; no-MHD: n = 15,523) were included. MHDs identified: depressive (57.8%), anxiety (28.1%), sleep (25.2%), and stress (2.9%). CR patients had greater prevalence of comorbid MHD than CM patients (P = 0.015). Two years postoperatively, all patients with MHD had significantly higher rates of complications (specifically: device-related, infection), readmission for any indication, and revision surgery (all P < 0.05); regression modeling corroborated these findings and revealed combined surgical approach as the strongest predictor for any complication (CR, odds ratio [OR]: 3.945, P < 0.001; CM, OR: 2.828, P < 0.001) and MHD as the strongest predictor for future revision (CR, OR: 1.269, P = 0.001; CM, OR: 1.248, P = 0.008) in both CR and CM cohorts.

CONCLUSION

Nearly 25% of patients admitted for CR and CM carried comorbid MHD and experienced greater rates of any complication, readmission, or revision, at minimum, 2 years after cervical spine surgery. Results must be confirmed with retrospective studies utilizing larger national databases and with prospective cohort studies. Patient counseling and psychological screening/support are recommended to complement surgical treatment.

LEVEL OF EVIDENCE

3.

Cervical spondylotic myelopathy patients with prior cerebral infarction: Clinical characteristics, surgical outcomes and prognostic value of "prior cerebral infarction"

OBJECTIVE

To investigate the clinical characteristics and surgical outcomes of patients with cervical spondylotic myelopathy (CSM) and prior cerebral infarction (CI); to identify whether "prior CI" correlates with poor surgical outcomes.

PATIENTS AND METHODS

Twenty-two patients with CSM and prior CI were retrospectively reviewed and included as the CI group while 100 CSM patients without CI were included as the control group (matched for gender, age, symptom duration and surgical approach). Extensive demographic and surgery-related data for patients in both groups were collected and compared. Multivariate logistic regression analysis was performed to assess all potential factors affecting surgical outcomes.

RESULTS

Compared to the control group, the CI group had the following: significantly higher percentages of hypertension, "progressive myelopathy", "rapid progressive myelopathy" and "intramedullary T2-weighted hyperintensity on MRI"; lower mean "preoperative mJOA score" and "postoperative mJOA score"; higher percentages of "preoperative mJOA score ≤11″ and "recovery rate of mJOA score <50%". In the CI group, 14 patients had CI within 6 months before CSM, and their percentage of "rapid progressive myelopathy" was higher than that of patients who had CI over 6 months before CSM. Logistic regression analysis showed that smoking, "symptom duration ≥12 months", "T2-weighted hyperintensity" and "prior CI" correlated with poor surgical outcome.

CONCLUSION

Rapid progressive myelopathy with advanced neurological impairment and "intramedullary T2-weighted hyperintensity" are common in patients with CSM and prior CI. Surgical outcomes in these patients are poorer than those of ordinary CSM patients. "Prior CI" is a risk factor for predicting poor surgical outcomes.

Integrative Korean medicine as a possible conservative treatment for mild cervical spondylotic myelopathy: One-year follow-up case report (CARE-compliant)

RATIONALE

Cervical spondylotic myelopathy (CSM) is the most common spinal cord disorder in older patients. The purpose of this case report is to introduce conservative treatment with integrative Korean medicine (KM) as a possible alternative to surgery in patients with mild CSM.

PATIENT CONCERNS

An 81-year-old male with both hand weakness and dysesthesia was diagnosed with CSM and was recommended laminectomy. However, considering the patient's age and the underlying disease, he refused immediate surgery and preferred KM treatment DIAGNOSES:: The diagnosis of mild CSM was based on a modified Japanese Orthopedic Association (mJOA) score as well as the presence of compression on the spinal cord in magnetic resonance imaging findings INTERVENTIONS:: Integrative KM treatment consisting of acupuncture, acupotomy, Bee venom herbal acupuncture, cupping therapy, moxibustion, and herbal medicine was provided during the 12-week admission.

OUTCOMES

Clinical improvement was detected with a mJOA score (11 to 17), a numerical rating scale for dysesthesia intensity (5 to 2), finger escape sign (+/+ to +/-), grip and release test (11/14 to 32/31) and grasp power measured by dynamometer (3.1/9.7 to 10.8/18.3 kg) at 12 weeks. This improvement was maintained without surgery until 1 year.

LESSONS

This case suggests that integrative KM was a possible conservative management option for mild CSM.

Clinico-Radiographic Discordance: An Evidence-Based Commentary on the Management of Degenerative Cervical Spinal Cord Compression in the Absence of Symptoms or With Only Mild Symptoms of Myelopathy

STUDY DESIGN

Narrative review with commentary.

OBJECTIVES

The growing use of magnetic resonance imaging (MRI) often leaves clinicians faced with scenarios where imaging findings are inconsistent with the clinical picture. This is particularly relevant for degenerative cervical spinal cord compression (CSCC). In this article, we provide a focused narrative literature review to address whether (1) surgery should be offered to asymptomatic patients with CSCC and (2) should MRI spinal cord signal changes influence clinical decisions for a patient with mild myelopathy from CSCC?

METHODS

Illustrative cases are presented with expert commentary which is supplemented by a focused literature review.

RESULTS

The literature suggests that CSCC from degenerative pathology is a common incidental radiographic finding. For those without symptoms of myelopathy, the short-term risk of progression is low. There is a lack of evidence to support surgery for asymptomatic individuals with CSCC who have no risk factors for progression. For these patients, the authors suggest non-operative management that includes education on the symptoms of myelopathy, clinical follow-up within 6 to 12 months, and avoidance of high-risk activities. Conversely, symptomatic patients have a notable risk of progression. Surgical intervention improves neurological function and quality of life regardless of severity. The authors support surgery as an option for all patients with mild myelopathy who are appropriate operative candidates. Intramedullary signal change on MRI has not been shown to reliably predict progression.

CONCLUSIONS

While MRI technologies are under evolution, we advise that surgical decisions for patients with CSCC should rely on clinical assessment and not imaging findings.

Outcomes of Surgical Decompression in Patients With Very Severe Degenerative Cervical Myelopathy

STUDY DESIGN

A prospective observational international study.

OBJECTIVE

The aim of this study was to evaluate outcomes of decompressive surgery in patients with very severe degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Although decompressive surgery has been evidenced as a safe and effective approach for patients with myelopathic deficiencies, studies have suggested residual disability following treatment in patients with more severe disease presentation.

METHODS

Postoperative outcomes of 60 patients with very severe DCM (modified Japanese Orthopaedic Association [mJOA] score ≤8) were compared to outcomes of 188 patients with severe DCM (mJOA 9-11). Postimputation follow-up rate was 93.1%. Unadjusted and adjusted analyses were performed using two-way repeated measures of covariance.

RESULTS

The two cohorts were similar in demographics, length of duration of myelopathy symptoms, source of stenosis, and surgical approaches used to decompress the spine. The very severe and severe cohorts differed in preoperative Nurick grades (4.97 vs. 3.91, respectively, P < 0.0001) and Neck Disability Index scores (45.20 vs. 56.21, respectively, P = 0.0006). There were no differences in Short Form 36 (SF-36v2) physical (PCS) and mental (MCS) component summary scores. Both cohorts improved in mJOA, Nurick, Neck Disability Index, and SF-36v2 PCS and MCS scores. Despite the substantial postoperative improvements, patients in both cohorts had considerable residual symptoms. Two-thirds of the patients in the very severe cohort had severe (mJOA ≤11) or moderate (mJOA ≤ 14) myelopathy symptoms at 24 months follow-up. Longer duration of disease was associated with poorer treatment response.

CONCLUSION

Decompressive surgery is effective in patients with very severe DCM; however, patients have significant residual symptoms and disability. The very severe subgroup (mJOA ≤8) of patients with DCM represents a distinct group of patients and their different clinical trajectory is important for clinicians and patients to recognize. Duration of symptoms negatively affects chances for recovery. Whenever possible, patients with DCM should be treated before developing very severe symptomatology.

LEVEL OF EVIDENCE

2.

CLINICAL AND FUNCTIONAL RESULTS IN PATIENTS WITH CERVICAL SPONDYLOTIC MYELOPATHY TREATED SURGICALLY BY ANTERIOR APPROACH IN A TERTIARY HEALTH CARE CENTER

ABSTRACT Objective: To evaluate the clinical and functional results in patients with cervical spondylotic myelopathy treated surgically by anterior approach in a reference center. Methods: An observational, longitudinal, analytical study was carried out. The patients were evaluated using the JOA, Nurick and SF12v2 scales at hospital admission, at 3 and 6 months after surgery, analyzing the data with the Student's T test in the IBM SPSS Statistics version 24. Results: The male sex predominated, the mean age was 61 years; the mean JOA score before surgery, at 3 and 6 months was 8, 10.9, and 11.6, respectively. The Nurick scale obtained a presurgical score, at 3 and 6 months of 2.8, 2.2, and 1.9, respectively. Regarding the quality of life (PCS), 93.3% of the patients were found to be below the mean, 2.2% in the mean, and 4.5% above the mean, while at 6 months, 91.1% of the patients were below the mean, 6.7% in the mean, and 2.2% above the mean. In the preoperative evaluation the SF 12v2 scale, 68.9% of the patients were below the mean, 2.2% in the mean, and 28.9% above the mean, being that at 6 months, 31.1% of the patients were below the mean, 15.6% in the mean, and 53.3% above the mean. A statistically significant improvement was observed with the JOA and Nurick scales from preoperative to 3 and 6 months (p<0.05) with a statistically significant difference in the mental component of quality in the same periods. Conclusions: Anterior approach decompression gives a significant clinical improvement at 3 and 6 months. However, this improvement does not correlate with the patient's perception of his or her health condition. Level of Evidence III; Case control study.

Decompression for botulinum toxin-exacerbated cervical myeloradiculopathy in the setting of congenital stenosis and Arnold-Chiari I malformation

Introduction

We present a case describing the management of a woman with severe, functionally limiting cervical myeloradiculopathy in the setting of congenital cervical canal stenosis and Arnold-Chiari I malformation.

Case presentation

The subject is a 57-year-old woman with prior anterior cervical discectomy and fusion who presented with left-sided neck pain associated with radiculopathy, migraine, gait incoordination, and cervical dystonia. Cervical stenosis and Chiari malformation were confirmed using MRI. Conservative management with botulinum toxin, oral muscle relaxants, and cervical brace led to gradual exacerbation of symptoms. Due to failure of conservative management, surgical decompression with C3-C6 posterior laminoplasty was performed, resulting in complete resolution of all symptoms and markedly improved quality of life.

Discussion

This case reports a severe and nonspecific presentation of cervical myeloradiculopathy. Surgery for cervical myeloradiculopathy is controversial, and conservative therapy is initially preferred. However, in this case, conservative treatments likely led to paraspinal weakness, cervical hypermobility, and biomechanical instability, resulting in exacerbation of symptoms. Stretch/shear forces have been postulated to accelerate cervical myelopathy, and excessive cervical instability and range of motion are significant predictors of deterioration. In this case, surgical decompression with posterior cervical laminoplasty after 1 year of conservative management yielded significant pain relief and functional restoration, indicating the utility of this procedure even in the presence of Arnold-Chiari I malformation. This case illustrates that decompression can be effective for refractory cervical myeloradiculopathy associated with Chiari malformation, congenital stenosis, and prior anterior instrumentation, and highlights the potential risks of prolonged conservative management.

[Degenerative cervical spine diseases: fusion vs. total disc replacement : What can be done when?]

Motion preserving surgery within the cervical spine may be performed by special implants, for example, c spine disc prosthesis or total disc replacement (cTDR), or by simple decompression of the cervical nerve roots. However, also fusion surgery may be performed with good results. Here, we summarize indications as well as contraindications for motion preserving techniques and indications for fusion surgery. cTDR is indicated in special cases of soft disc herniation, especially in younger individuals without signs of myelopathy. Posterior decompression may be used as an alternative, especially if anterior surgery is not possible. If degeneration is severe, in the presence of kyphosis, severe canal encroachment, instability, and in cases of myelopathy, cervical spine fusion seems to be the better way.

Is there a role for postoperative physiotherapy in degenerative cervical myelopathy? A systematic review

Objective:

To review peer-reviewed literature relating to postoperative physiotherapy for degenerative cervical myelopathy (DCM), to determine efficacy in improving clinical outcome and recovery.

Data sources:

MEDLINE, EMBASE, CENTRAL, PEDro, ISRCTN registry, WHO ICTRP and Clinicaltrials.gov . References and citations of relevant articles were searched.

Methods:

A systematic search was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO CRD42016039511) from the origins of the databases till 15 February 2018. Included were all studies investigating physiotherapy as an intervention after surgical treatment of DCM to determine effect on clinical outcome and recovery. Study quality was determined using the Grades of Recommendation, Assessment, Development and Evaluation guidelines.

Results:

In all, 300 records were identified through tailored systematic searches, after removing duplicates. After screening, only one investigated postoperative rehabilitation using physiotherapy for DCM; however, this was retrospective with no controls. This study suggested that rehabilitation including physiotherapy improved postoperative recovery. There are currently two registered trials investigating the use of postoperative physiotherapy for DCM.

Conclusions:

The literature provides insufficient evidence to make any evidence-based recommendations regarding postoperative physiotherapy use in DCM.

Monitoring for myelopathic progression with multiparametric quantitative MRI

Background

Patients with mild degenerative cervical myelopathy (DCM) are often managed non-operatively, and surgery is recommended if neurological progression occurs. However, detection of progression is often subjective. Quantitative MRI (qMRI) directly measures spinal cord (SC) tissue changes, detecting axonal injury, demyelination, and atrophy. This longitudinal study compared multiparametric qMRI with clinical measures of progression in non-operative DCM patients.

Methods

26 DCM patients were followed. Clinical data included modified Japanese Orthopedic Association (mJOA) and additional assessments. 3T qMRI data included cross sectional area, diffusion fractional anisotropy, magnetization transfer ratio, and T2*-weighted white/grey matter signal ratio, extracted from the compressed SC and above/below. Progression was defined as 1) patients’ subjective impression, 2) 2-point mJOA decrease, 3) ≥3 clinical measures worsening ≥5%, 4) increased compression on MRI, or 5) ≥1 of 10 qMRI measures or composite score worsening (p < 0.004, corrected).

Results

Follow-up (13.5 ± 4.9 months) included mJOA in all 26 patients, MRI in 25, and clinical/qMRI in 22. 42.3% reported subjective worsening, compared with mJOA (11.5%), MRI (20%), comprehensive assessments (54.6%), and qMRI (68.2%). Relative to subjective worsening, qMRI showed 100% sensitivity and 53.3% specificity compared with comprehensive assessments (75%, 60%), mJOA (27.3%, 100%), and MRI (18.2%, 81.3%). A decision-making algorithm incorporating qMRI identified progression and recommended surgery for 11 subjects (42.3%).

Conclusions

Quantitative MRI shows high sensitivity to detect myelopathic progression. Our results suggest that neuroplasticity and behavioural adaptation may mask progressive SC tissue injury. qMRI appears to be a useful method to confirm subtle myelopathic progression in individual patients, representing an advance toward clinical translation of qMRI.

Geographic variations in clinical presentation and outcomes of decompressive surgery in patients with symptomatic degenerative cervical myelopathy: analysis of a prospective, international multicenter cohort study of 757 patients

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness.

PURPOSE

The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions.

STUDY DESIGN/SETTING

This is a multicenter international prospective cohort study.

PATIENT SAMPLE

This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine.

OUTCOME MEASURES

The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade.

MATERIALS AND METHODS

The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America.

RESULTS

Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe.

CONCLUSIONS

Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

Bundled payment reimbursement for anterior and posterior approaches for cervical spondylotic myelopathy: an analysis of private payer and Medicare databases

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is a progressive spinal condition that often requires surgery. Studies have shown the clinical equivalency of anterior versus posterior approaches for CSM surgery. The purpose of this study was to determine the amount and type of resources used for anterior and posterior surgical treatment of CSM by using large national databases of clinical and financial information from patients.

METHODS

This study consists of 2 large cohorts of patients who underwent either an anterior or posterior approach for treatment of CSM. These patients were selected from the Medicare 5% National Sample Administrative Database (SAF5) and the Humana orthopedic database (HORTHO), which is a database of patients with private payer health insurance. The outcome measures were the cost of a 90-day episode of care, as well as a breakdown of the cost components for each surgical procedure between 2005 and 2014.

RESULTS

A total of 16,444 patients were included in this analysis. In HORTHO, there were 10,332 and 1556 patients treated with an anterior or posterior approach for CSM, respectively. In SAF5, there were 3851 and 705 patients who were treated by an anterior or posterior approach for CSM, respectively. The mean ± SD reimbursements for anterior and posterior approaches in the HORTHO database were $20,863 ± $2014 and $23,813 ± $4258, respectively (p = 0.048). The mean ± SD reimbursements for anterior and posterior approaches in the SAF5 database were $18,219 ± $1053 and $25,598 ± $1686, respectively (p < 0.0001). There were also significantly higher reimbursements for a rehabilitation/skilled nursing facility and hospital/inpatient care for patients who underwent a posterior approach in both the private payer and Medicare databases. In all cohorts in this study, the hospital-related reimbursement was more than double the surgeon-related reimbursement.

CONCLUSIONS

This study provides resource utilization information for a 90-day episode of care for both anterior and posterior approaches for CSM surgery. There is a statistically significant higher resource utilization for patients undergoing the posterior approach for CSM, which is consistent with the literature. Understanding the reimbursement patterns for anterior versus posterior approaches for CSM will help providers design a bundled payment for patients requiring surgery for CSM, and this study suggests that a subset of patients who require the posterior approach for treatment also require greater resources. The data also suggest that hospital-related reimbursement is the major driver of payments.

Reproducibility, temporal stability, and functional correlation of diffusion MR measurements within the spinal cord in patients with asymptomatic cervical stenosis or cervical myelopathy

OBJECTIVE The purpose of this study was to quantify the reproducibility, temporal stability, and functional correlation of diffusion MR characteristics in the spinal cord in patients with cervical stenosis with or without myelopathy. The association between longitudinal diffusion tensor imaging (DTI) measurements and serial neurological function assessment was explored at both the group and individual level. METHODS Sixty-six nonoperatively treated patients with cervical stenosis were prospectively followed (3 months to > 5 years) using synchronous serial MRI and functional outcome assessment. A total of 183 separate MRI examinations were performed, separated by at least 3 months, and each patient had a minimum of 2 MRI scans (range 2-5 scans). Anatomical and DTI measurements were performed within the spinal cord at the C1-2 region as well as at the area of highest compression. Coefficients of variance (COVs) were compared across measurements in both reference tissue and areas of compression for anatomical measurements, fractional anisotropy (FA), and mean diffusivity (MD). The correlation between diffusion MR measures at the site of compression and evaluations of neurological function assessed using the modified Japanese Orthopaedic Association (mJOA) scale at multiple time points was evaluated. RESULTS The COVs for anatomical measurements (Torg ratio and canal diameter) were between 7% and 10%. The median COV for FA measurements at the site of compression was 9%, and for reference tissue at C1-2 it was 6%. The median COV for MD at the site of compression was approximately 12%, and for reference tissue at C1-2 it was 10%. The FA and MD measurements of C1-2 averaged 0.61 and 0.91 μm²/msec, respectively, whereas the FA and MD measurements at the site of compression averaged 0.51 and 1.26 μm²/msec, respectively. Both FA (slope = 0.037; R² = 0.3281, p < 0.0001) and MD (slope = -0.074; R² = 0.1101, p = 0.0084) were significantly correlated with the mJOA score. The FA decreased by approximately 0.032 units per mJOA unit decrease (R² = 0.2037, p < 0.0001), whereas the MD was increased by approximately 0.084 μm²/msec for every mJOA unit decrease (R² = 0.1016, p < 0.0001). CONCLUSIONS Quantitative DTI measurements of the spinal cord in patients with cervical stenosis with or without myelopathy have a median COV of 5%-10%, similar to anatomical measurements. The reproducibility of these measurements and significant correlation with functional outcome status suggest a potential role in the evaluation and longitudinal surveillance of nonoperatively treated patients. With respect to the specific DTI measurements, FA within the spinal cord appears slightly more sensitive to neurological function and more stable than measures of MD. Therefore, DTI of the spinal cord may be a clinically feasible imaging technique for longitudinally monitoring patients with cervical spondylotic myelopathy.

Global Spinal Alignment in Patients With Cervical Spondylotic Myelopathy

STUDY DESIGN

A prospective radiographic analysis of cervical spondylotic myelopathy (CSM).

OBJECTIVE

The aim of this study was to clarify the pathophysiology of CSM, and use the characteristic of global spinal alignment for determining the surgical strategy.

SUMMARY OF BACKGROUND DATA

Radiographic evaluation of CSM, in general, comprises cervical magnetic resonance imaging (MRI) and regional cervical radiography, which cannot distinguish between cervical hyperlodorsis with spinopelvic compensation and cervical lordorsis with normal global alignment.

METHODS

Our inclusion criteria were preoperative whole spine radiography and cervical MRI and health-related quality of life scores. Global spinal alignment was characterized by cervical lordosis (CL), C7 sagittal vertical axis (SVA), T1 slope (T1S), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and knee flexion angle (KFA). Cervical alignment was characterized by O-C2, C2-4, C5-7, and C2-7 angles; cranial center of gravity (CCG) C7SVA; and C2-7 SVA. Responsible lesion determined using MRI was divided from C2/3 to C7/T1.

RESULTS

Eighty-eight surgically treated CSM patients with EOS full spine imaging were prospectively analyzed. There were 72 normal (Type 1; SVA <50 mm) and 16 positive (Type 2; SVA ≥50 mm) global balance patients. There were significant differences in age, T1S, KFA, T1S-CL, SVA, CCG-SVA, and C2-7 SVA between Type 1 and Type 2. C3/4 lesion was more common in Type 2 than in Type 1. There was a positive correlation between global sagittal, but not regional, balance, and responsible lesion. C3/4 lesion was more frequent in older, male, high SVA, large T1S-CL, large KFA, and large cranial lordosis (C2-4/C5-7 angle) patients.

CONCLUSION

This study indicates the necessity for global alignment evaluation, particularly in older CSM patients because of their compensation mechanism for global malalignment. Surgical strategy for cranial type CSM should be carefully selected considering global balance.

LEVEL OF EVIDENCE

4.

Anterior corpectomy and reconstruction using dynamic cervical plate and titanium mesh cage for cervical spondylotic myelopathy: A minimum 5-year follow-up study

Anterior cervical corpectomy and fusion (ACCF) is an effective surgical technique for cervical spondylotic myelopathy (CSM). However, no data exist regarding long-term outcomes after ACCF with the dynamic cervical plate for CSM. This study aimed to provide minimum 5-year clinical and radiographic outcomes of anterior corpectomy and reconstruction using dynamic cervical plate and titanium mesh cage (TMC) for CSM.Thirty-five patients who underwent single- or 2-level ACCF with dynamic cervical plate and TMC for the treatment of CSM were retrospectively investigated. The Japanese Orthopedic Association (JOA) score was used to assess the clinical outcome. Radiographic evaluations included TMC subsidence, fusion status, cervical lordosis, segmental angle, and segmental height.Twenty-eight patients underwent single-level and 7 patients underwent 2-level corpectomy with a mean follow-up period of 69.5 months. The average preoperative JOA score was 11.3 ± 3.0 and improved significantly to 14.2 ± 2.0 at the last follow-up (P < .001). Both cervical lordosis (P = .013) and segmental angle (P = .001) were significantly increased toward lordosis at the last follow-up. The TMC subsidence rate was 31.4% (n = 11) at the last follow-up. There was no significant difference in JOA recovery rate between subsidence and no subsidence group (P = .43). All patients obtained solid fusion at 1-year follow-up.Anterior corpectomy and reconstruction with dynamic cervical plate and TMC might be an effective method for the treatment of CSM at a minimum 5-year follow-up. It can maintain or restore cervical sagittal alignment. Subsidence of the TMC did not influence the clinical outcome.

Open-door laminoplasty : What can the unilateral approach offer?

OBJECTIVE

Multilevel posterior decompression of subaxial cervical spinal canal stenosis through a less-invasive unilateral approach.

INDICATIONS

Degenerative cervical myelopathy due to multilevel subaxial spinal canal stenosis.

CONTRAINDICATIONS

Cervical kyphosis or instability, bilateral radiculopathy due to foraminal stenosis, involvement of C2 or C7.

SURGICAL TECHNIQUE

Unilateral subaxial approach with detachment of muscles only on one side. The ipsilateral laminae C6 to C3 are cut at the laminofacet junction and opened up. The loss of resistance is usually due to a greenstick fracture in the proximity of the contralateral laminofacet junction. The opened laminae are fixed with Z‑shaped thin titanium plates. If necessary, the laminoplasty can be combined with a unilateral fixation and fusion by the same approach.

POSTOPERATIVE MANAGEMENT

Early mobilization 4-6 h postoperatively. No orthosis necessary.

RESULTS

A total of 131 patients (77 men, mean age 67 years) with a multilevel cervical spondylotic myelopathy (CSM) underwent surgery using a posterior approach. In 52 patients (40%), a unilateral approach was performed (laminoplasty: n = 30; laminoplasty/fusion: n = 22). In this group, the mean operation time was less compared with two other techniques (unilateral approach: 110 min; laminectomy/fusion: 150 min; 360° approach: 210 min). The postoperative European myelopathy score (EMS) improved from 12.8 to 15.2. The overall complication rate was 17% (unilateral approach: 9%; laminectomy/fusion: 18%; 360° approach: 27%).

The Global Spine Care Initiative: a summary of guidelines on invasive interventions for the management of persistent and disabling spinal pain in low- and middle-income communities

PURPOSE

The purpose of this study was to synthesize recommendations on the use of common elective surgical and interventional procedures for individuals with persistent and disabling non-radicular/axial with or without myelopathy, radicular back pain, cervical myelopathy, symptomatic spinal stenosis, and fractures due to osteoporosis. This review was to inform a clinical care pathway on the patient presentations where surgical interventions could reasonably be considered.

METHODS

We synthesized recommendations from six evidence-based clinical practice guidelines and one appropriate use criteria guidance for the surgical and interventional management of persistent and disabling spine pain.

RESULTS

Lower priority surgery/conditions include fusion for lumbar/non-radicular neck pain and higher priority surgery/conditions include discectomy/decompressive surgery for cervical or lumbar radiculopathy, cervical myelopathy, and lumbar spinal stenosis. Epidural steroid injections are less expensive than most surgeries with fewer harms; however, benefits are small and short lived. Vertebroplasty should be considered over kyphoplasty as an option for patients with severe pain and disability due to osteoporotic vertebral compression fracture.

CONCLUSION

Elective surgery and interventional procedures could be limited in medically underserved areas and low- and middle-income countries due to a lack of resources and surgeons and thus surgical and interventional procedures should be prioritized within these settings. There are non-invasive alternatives that produce similar outcomes and are a recommended option where surgical procedures are not available. These slides can be retrieved under Electronic Supplementary Material.

Ultrastructural Features of Neurovascular Units in a Rat Model of Chronic Compressive Spinal Cord Injury

Chronic spinal cord compression is the most common cause of spinal cord impairment worldwide. Objective of this study is to assess the ultrastructural features of the neurovascular unit (NVU) in a rat model of chronic compressive spinal cord injury, 24 SD rats were divided into two groups: the control group (n = 12), and the compression group (n = 12). A C6 semi-laminectomy was performed in the control group, whereas a water-absorbent polyurethane polymer was implanted into the C6 epidural space in the compression group. The Basso Beattie Bresnahan (BBB) scores and the somatosensory evoked potentials (SEP) were used to evaluate neurological functions. Transmission Electron Microscopy (TEM) was performed to investigate the change of NVU at the 28th day after modeling. Compared with the control group, the compression group shows a significant reduction (P < 0.05) of BBB score and a significant severity (P < 0.05) of abnormal SEP. TEM results of the compression group showed a striking increase in endothelial caveolae and vacuoles; a number of small spaces in tight junctions; a significant increase in pericyte processing area and vessel coverage; an expansion of the basement membrane region; swollen astrocyte endfeet and mitochondria; and the degeneration of neurons and axons. Our study revealed that damage to NVU components occurred followed by chronic compressive spinal cord injury. Several compensatory changes characterized by thicker endothelium, expansive BM, increased pericyte processing area and vessel coverage were also observed.

Oblique corpectomy in the cervical spine

STUDY DESIGN

A narrative review.

OBJECTIVES

A literature review of studies reporting on the application of oblique corpectomy (OC) in various pathologies of the cervical spine.

SETTING

UK.

METHODS

A search was carried out using the PubMed and Google Scholar up to 18 March 2017. Finally, 26 studies met the inclusion criteria.

RESULTS

A multilevel OC shows good clinical outcomes in various pathologies in the cervical spine. The clinical improvement in cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament was found to be over 70%. OC allows wide anterior decompression of the spinal cord and complete unilateral nerve root decompression. The approach carries a risk of Horner's syndrome, vertebral artery and accessory nerve injury. OC does not compromise spine stability and osteoarthrodesis with bone grafting is not necessary. Spinal motions are preserved and appear close to normal. OC can be applied in patients with a low fusion rate such as the elderly, diabetics, and heavy smokers. Furthermore, OC was found to be an optimal approach for exta-intradural tumors of the cervical spine.

CONCLUSIONS

OC seems to be a valid alternative for the management of multisegmental CSM in selected cases. It should not be considered a first-line treatment strategy due to the relatively high morbidity. There are no studies comparing OC without fusion to other treatment options in CSM. Therefore, rigorous prospective studies using validated outcome measures with long-term follow-up are required.

Anterior transcorporeal tunnel approach for cervical myelopathy guided by CT-based intraoperative spinal navigation: Technical note

Cervical spondylotic myelopathy (CSM) is the most common degenerative disease of the spine in elderly patients. Although there are several surgical options for the treatment of this disease, minimally invasive techniques for localized decompression of the true clinical generator of the patient's disease has revolutionized spinal surgery recently. This article presents an alternate application of the anterior transcorporeal tunnel approach in combination with computed tomography (CT)-based intraoperative navigation in the treatment of patients with cervical myelopathy secondary to spondylosis. Three clinical cases are used as examples to demonstrate how this procedure can be used to decompress a localized target in cervical spondylotic myelopathy. Clinical images of each case are shown. Cervical decompression was successfully achieved in all three patients, with the improvement of preoperative symptoms. The anterior transcorporeal tunnel approach combined with the use of CT-based intraoperative spinal navigation may be a feasible minimally invasive procedure for the treatment of cervical spondylotic myelopathy in selected cases.

Preoperative cervical sagittal alignment parameters and their impacts on myelopathy in patients with cervical spondylotic myelopathy: a retrospective study

Background

Cervical sagittal alignment plays an important role in the pathogenesis of cervical spondylotic myelopathy (CSM), but there are limited studies on the cervical sagittal parameters in CSM patients and their correlations with myelopathy. The aim of this study is to investigate the correlations among the preoperative cervical sagittal alignment parameters and their correlations with the development of myelopathy in patients with CSM.

Methods

We retrospectively collected 212 patients with CSM who underwent surgical interventions. Gender, age, modified Japanese Orthopedic Association score (mJOA), cervical lordosis (CL), C2–C7 sagittal vertical axis (C2–C7 SVA), T1 slope (T1S), neck tilt (NT) and thoracic inlet angle (TIA) were collected before operation. Interobserver and intraobserver reliability were calculated for all measurements (intraclass correlation coefficient, ICC). Data were analyzed with Pearson and Spearman correlation tests and multiple linear regression analysis.

Results

A total of 212 patients with CSM were included in this study (male: 136, female: 76) with an average age of 54.5 ± 10.1 years old. Intraobserver and interobserver reliability for all included radiographic parameters presented good to excellent agreement (ICC > 0.7). No significant differences in demographic and radiological parameters have been observed between males and females (P > 0.05). We found statistically significant correlations among the following parameters: age with CL (r = 0.135, P = 0.049), age with T1S (r = 0.222, P = 0.001), CL with T1S (r = 0.291, P < 0.001), CL with C2-C7 SVA (r =  − 0.395, P < 0.001), mJOA with age (r =  − 0.274, P < 0.001), mJOA with C2–C7 SVA (r =  − 0.219, P < 0.001) and mJOA with T₁S(r =  − 0.171, p = 0.013). Linear regression analysis showed that C2–C7 SVA was the predictor of CL (adjusted R² = 0.152, P < 0.001) and multiple linear regression showed that age combined with C2–C7 SVA was a sensitive predictor of mJOA (adjusted R² = 0.106, P < 0.001).

Discussion

There were significant correlations among certain preoperative cervical sagittal parameters in CSM patients. CL was the only predictor of C2–C7 SVA. Age combined with C2–C7 SVA could predict the severity of myelopathy.