Prediction of lower limb functional recovery after laminoplasty for cervical myelopathy: focusing on the 10-s step test

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.

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.

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.

Imaging and Electrophysiology for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 9]

STUDY DESIGN

Narrative review.

OBJECTIVE

The current review aimed to describe the role of existing techniques and emerging methods of imaging and electrophysiology for the management of degenerative cervical myelopathy (DCM), a common and often progressive condition that causes spinal cord dysfunction and significant morbidity globally.

METHODS

A narrative review was conducted to summarize the existing literature and highlight future directions.

RESULTS

Anatomical magnetic resonance imaging (MRI) is well established in the literature as the key imaging tool to identify spinal cord compression, disc herniation/bulging, and inbuckling of the ligamentum flavum, thus facilitating surgical planning, while radiographs and computed tomography (CT) provide complimentary information. Electrophysiology techniques are primarily used to rule out competing diagnoses. However, signal change and measures of cord compression on conventional MRI have limited utility to characterize the degree of tissue injury, which may be helpful for diagnosis, prognostication, and repeated assessments to identify deterioration. Early translational studies of quantitative imaging and electrophysiology techniques show potential of these methods to more accurately reflect changes in spinal cord microstructure and function.

CONCLUSION

Currently, clinical management of DCM relies heavily on anatomical MRI, with additional contributions from radiographs, CT, and electrophysiology. Novel quantitative assessments of microstructure, perfusion, and function have the potential to transform clinical practice, but require robust validation, automation, and standardization prior to uptake.

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.

Risk Factors for Poor Outcome of Cervical Laminoplasty: Multivariate Analysis in 505 Patients with Cervical Spondylotic Myelopathy

The risk factors for poor outcome after cervical laminoplasty in patients with cervical spondylotic myelopathy (CSM) were demonstrated. These findings suggest that advanced age, long-term CSM symptoms, and lower score of preoperative 10-second step test are risk factors for poor cervical laminoplasty outcomes in patients with CSM.

Study Design..

A prospective study.

Objective..

The aim of this study was to characterize the risk factors for poor outcome following cervical laminoplasty in patients with cervical spondylotic myelopathy (CSM).

Summary of Background Data..

Previous research has identified a variety of potential predictive factors that might affect outcomes after cervical laminoplasty. However, no study till date has assessed the effects of such risk factors, including internal medicine comorbidity and quantitative performance tests, on the outcome of laminoplasty in a large series of patients with CSM.

Methods..

A total of 505 consecutive patients with CSM (311 males; 194 females; mean age, 66.6 years; age range, 41–91 years) who underwent double-door laminoplasty were prospectively included. The average postoperative follow-up period was 26.5 months (range, 12–66 months). We evaluated the recovery rate (RR) on the basis of the Japanese Orthopaedic Association score. Logistic regression analysis was performed to identify the risk factors for poor outcome, which was defined as a postoperative RR of <50%. Relationship between outcome and various clinical and imaging predictors was examined.

Results..

Two hundred ninety-five patients had good outcomes with RR >50%, whereas 210 patients had poor outcomes with RR <50%. Compared with the good-outcome group, the poor-outcome group had a significantly higher prevalence of diabetes and hypertension and use of anticoagulant/antiplatelet agent and smoking history (P < 0.05). Multivariate logistic regression analysis showed independent risks associated with increased age (odds ratio [ORs]  = 1.029, 95% confidence interval [CI] = 1.004–1054, P = 0.023). Logistic regression analysis determined that symptom duration of CSM (OR = 1.017, 95% CI = 1.008–1.026, P < 0.001) and preoperative 10-second step test (OR = 0.922, 95% CI = 0.865–0.983, P = 0.013) were significant risk factors for poor outcome.

Conclusion..

These findings suggest that advanced age, long-term CSM symptoms, and lower score of preoperative 10-second step test are risk factors for poor outcome in patients with CSM.

Level of Evidence: 2

Baseline severity of myelopathy predicts neurological outcomes after posterior decompression surgery for cervical spondylotic myelopathy: a retrospective study

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVES

To identify the usefulness of the baseline severity of myelopathy for predicting surgical outcomes for cervical spondylotic myelopathy (CSM).

SETTING

Seventeen institutions in Japan.

METHODS

This study included 675 persons with CSM who underwent posterior decompression. According to baseline severity, the individuals were divided into the mild (Japanese Orthopaedic Association [JOA] score ≥ 14.5), moderate (JOA score = 10.5-14), and severe (JOA score ≤ 10) groups. Surgical outcomes and clinical variables were compared between the groups. Logistic regression analysis was used to develop a prediction model for unsatisfactory symptom state (postoperative JOA score ≤ 14, residual moderate or severe myelopathy).

RESULTS

The mean (±standard deviation) age was 67 ± 12 years. The participants in the severe group were older than those in the mild group. Postoperative JOA scores were higher in the mild group than in the severe group. According to multivariate logistic regression analysis, the prediction model included preoperative JOA scores (odds ratio [OR] 0.60; 95% confidence interval [CI] 0.55-0.67) and age (OR 1.06, 95% CI 1.04-1.08). On the basis of the model, a representative combination of the thresholds to maximize the value of "sensitivity - (1 - specificity)" demonstrated a preoperative JOA score of 11.5 as a predictor of postoperative unsatisfactory symptom state in people around the mean age of the study cohort (67 years).

CONCLUSIONS

The combination of the baseline severity of myelopathy and age can predict postoperative symptom states after posterior decompression surgery for CSM.

Degenerative cervical myelopathy presenting as subjective lower limb weakness could be a trap towards misdiagnosis

When patients presenting with subjective lower limb weakness (SLLW) are encountered, it is natural to suspect a lumbar pathology and proceed with related clinical examination, investigations and management. However, SLLW could be a sign of degenerative cervical myelopathy (DCM) due to an evolving cord compression. In such circumstances, if symptoms are not correlated to myelopathy at the earliest, there could be potential complications over time. In this study, we intend to analyse the outcomes after surgical management of the cervical or thoracic cord compression in patients with SLLW. Retrospectively, patients who presented to our center during the years 2010–2016 with sole complaint of bilateral SLLW but radiologically diagnosed to have a solitary cervical or thoracic stenosis, or tandem spinal stenosis and underwent surgical decompression procedures were selected. Their clinical presentation was categorised into three types, myelopathy was graded using Nurick’s grading and JOA scoring; in addition, their lower limb functional status was assessed using the lower extremity functional scale (LEFS). Functional recovery following surgery was assessed at 6 weeks, 3 months, 6 months, one year, and two years. Selected patients (n = 24; Age, 56.4 ± 10.1 years; range 32–78 years) had SLLW for a period of 6.4 ± 3.2 months (range 2–13 months). Their preoperative JOA score was 11.3 ± 1.8 (range 7–15), and LEFS was 34.4 ± 7.7 (range 20–46). Radiological evidence of a solitary cervical lesion and tandem spinal stenosis was found in 6 and 18 patients respectively. Patients gradually recovered after surgical decompression with LEFS 59.8 ± 2.7 (range 56–65) at 1 year and JOA score 13.6 ± 2.7 (range − 17 to 100) at 2 years. The recovery rate at final follow up was 47.5%. Our results indicate the importance of clinically suspecting SLLW as an early non-specific sign of DCM to avoid misdiagnosis, especially in patients without conventional upper motor neuron signs. In such cases, surgical management of the cord compression resulted in significant functional recovery and halted the progression towards permanent disability.

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.

Degenerative cervical myelopathy - update and future directions

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults worldwide. DCM encompasses various acquired (age-related) and congenital pathologies related to degeneration of the cervical spinal column, including hypertrophy and/or calcification of the ligaments, intervertebral discs and osseous tissues. These pathologies narrow the spinal canal, leading to chronic spinal cord compression and disability. Owing to the ageing population, rates of DCM are increasing. Expeditious diagnosis and treatment of DCM are needed to avoid permanent disability. Over the past 10 years, advances in basic science and in translational and clinical research have improved our understanding of the pathophysiology of DCM and helped delineate evidence-based practices for diagnosis and treatment. Surgical decompression is recommended for moderate and severe DCM; the best strategy for mild myelopathy remains unclear. Next-generation quantitative microstructural MRI and neurophysiological recordings promise to enable quantification of spinal cord tissue damage and help predict clinical outcomes. Here, we provide a comprehensive, evidence-based review of DCM, including its definition, epidemiology, pathophysiology, clinical presentation, diagnosis and differential diagnosis, and non-operative and operative management. With this Review, we aim to equip physicians across broad disciplines with the knowledge necessary to make a timely diagnosis of DCM, recognize the clinical features that influence management and identify when urgent surgical intervention is warranted.

The Dubousset Functional Test is a Novel Assessment of Physical Function and Balance

BACKGROUND

Currently, the functional status of patients undergoing spine surgery is assessed with quality-of-life questionnaires, and a more objective and quantifiable assessment method is lacking. Dr. Jean Dubousset conceptually proposed a four-component functional test, but to our knowledge, reference values derived from asymptomatic individuals have not yet been reported, and these are needed to assess the test's clinical utility in patients with spinal deformities.

QUESTIONS/PURPOSES

(1) What are the reference values for the Dubousset Functional Test (DFT) in asymptomatic people? (2) Is there a correlation between demographic variables such as age and BMI and performance of the DFT among asymptomatic people?

METHODS

This single-institution prospective study was performed from January 1, 2018 to May 31, 2018. Asymptomatic volunteers were recruited from our college of medicine and hospital staff to participate in the DFT. Included participants did not report any musculoskeletal problems or trauma within 5 years. Additionally, they did not report any history of lower limb fracture, THA, TKA, or patellofemoral arthroplasty. Patients were also excluded if they reported any active medical comorbidities. Demographic data collected included age, sex, BMI, and self-reported race. Sixty-five asymptomatic volunteers were included in this study. Their mean age was 42 ± 15 years; 27 of the 65 participants (42%) were women. Their mean BMI was 26 ± 5 kg/m. The racial distribution of the participants was 34% white (22 of 65 participants), 25% black (16 of 65 participants), 15% Asian (10 of 65 participants), 9% subcontinental Indian (six of 65 participants), 6% Latino (four of 65 participants), and 10% other (seven of 65 participants). In a controlled setting, participants completed the DFT after verbal instruction and demonstration of each test, and all participants were video recorded. The four test components included the Up and Walking Test (unassisted sit-to-stand from a chair, walk forward/backward 5 meters [no turn], then unassisted stand-to-sit), Steps Test (ascend three steps, turn, descend three steps), Down and Sitting Test (stand-to-ground, followed by ground-to-stand, with assistance as needed), and Dual-Tasking Test (walk 5 meters forwards and back while counting down from 50 by 2). Tests were timed, and data were collected from video recordings to ensure consistency. Reference values for the DFT were determined via a descriptive analysis, and we calculated the mean, SD, 95% CI, median, and range of time taken to complete each test component, with univariate comparisons between men and women for each component. Linear correlations between age and BMI and test components were studied, and the frequency of verbal and physical pausing and adverse events was noted.

RESULTS

The Up and Walking Test was completed in a mean of 15 seconds (95% CI, 14-16), the Steps Test was completed in 6.3 seconds (95% CI, 6.0-6.6), the Down and Sitting Test was completed in 6.0 seconds (95% CI, 5.4-6.6), and the Dual-Tasking Test was performed in 13 seconds (95% CI, 12-14). The length of time it took to complete the Down and Sitting (r = 0.529; p = 0.001), Up and Walking (r = 0.429; p = 0.001), and Steps (r = 0.356; p = 0.014) components increased with as the volunteer's age increased. No correlation was found between age and the time taken to complete the Dual-Tasking Test (r = 0.134; p = 0.289). Similarly, the length of time it took to complete the Down and Sitting (r = 0.372; p = 0.005), Up and Walking (r = 0.289; p = 0.032), and Steps (r = 0.366; p = 0.013) components increased with increasing BMI; no correlation was found between the Dual-Tasking Test's time and BMI (r = 0.078; p = 0.539).

CONCLUSIONS

We found that the DFT could be completed by asymptomatic volunteers in approximately 1 minute, although it took longer for older patients and patients with higher BMI.

CLINICAL RELEVANCE

We believe, but did not show, that the DFT might be useful in assessing patients with spinal deformities. The normal values we calculated should be compared in future studies with those of patients before and after undergoing spine surgery to determine whether this test has practical clinical utility. The DFT provides objective metrics to assess function and balance that are easy to obtain, and the test requires no special equipment.

Minimum Clinically Important Difference and Patient Acceptable Symptom State of Japanese Orthopaedic Association Score in Degenerative Cervical Myelopathy Patients

STUDY DESIGN

A retrospective analysis.

OBJECTIVE

The aim of this study was to elucidate the psychometric properties of the original Japanese Orthopaedic Association (JOA) score, including the minimum detectable change (MDC), minimum clinically important difference (MCID), and patient-accepted symptom state (PASS).

SUMMARY OF BACKGROUND DATA

Despite the worldwide popularity of modified JOA score (mJOA), the original JOA score is still commonly used in East Asian countries, including Japan. However, unlike mJOA score, the psychometric properties of JOA score remain poorly understood.

METHODS

We retrospectively reviewed a consecutive series of laminoplasty for degenerative cervical myelopathy patients in a single academic institution. Pre- and postoperative JOA scores were collected, and the recovery rate was calculated. Anchor-based methods were used to determine the cut-off values by a receiver operating characteristic (ROC) curve analysis. The patients were also asked to answer an anchor question analyzing their postoperative health transition used for the MDC and another question assessing the patient satisfaction used for the MCID and PASS.

RESULTS

A total of 101 patients were included in the analysis. The mean preoperative JOA score was 10.3 [standard deviation (SD): 2.4), and the mean postoperative JOA score was 13.4 (SD: 2.5). The mean recovery rate was 44%. A total of 68% of the patients admitted that their health condition was at least "somewhat better" than their preoperative condition, and 66% were at least "somewhat satisfied" with the treatment results. On the basis of ROC curve analyses, the MDC and MCID for JOA score in degenerative cervical myelopathy patients were calculated to be 2.5. The PASS was estimated to be 14.5, and the MCID for JOA recovery rate was 52.8%.

CONCLUSION

The MDC, MCID, and PASS for JOA score for degenerative cervical myelopathy patients were reported by anchor-based ROC curve analyses.

LEVEL OF EVIDENCE

4.

Cervical spondylosis in patients presenting with "severe" myelopathy: Analysis of treatment by multisegmental spinal fixation - A case series

Background:

Surgical strategy of multisegmental spinal fixation that includes atlantoaxial joint for patients having cervical spondylosis-related symptoms of severe myelopathy is analyzed.

Objective:

Surgical outcome of patients presenting with “severe” symptoms of cervical myelopathy having multisegmental degenerative cervical spondylosis and treated by multisegmental spinal fixation is analyzed. Atlantoaxial joint was included in the fixation construct in majority of patients. No bone, soft tissue, osteophyte, or disc resection for decompression was done.

Materials and Methods:

Sixty-four patients having multisegmental cervical spondylosis who presented with symptoms of severe myelopathy were surgically treated during the period from March 2013 to December 2018. On the basis of the concept that instability is the primary cause of spinal degeneration, multisegmental spinal fixation was done in all patients. Atlantoaxial joint was included in the fixation construct in 48 patients. The levels of spinal fixation were determined on the basis of direct observation of facet joints and by manual manipulation and were guided by the presenting clinical features and radiological information. Clinical monitoring was done using Goel clinical grading, modified Japanese Orthopedic Association Score, and visual analog score parameters. Patient satisfaction index assessed the functional and symptomatic improvement.

Results:

During the follow-up that ranged from 6 to 75 months, all patients improved in their clinical status. Fifty-five (85.9%) patients could walk independently or with mild support.

Conclusions:

Multisegmental spinal fixation that includes atlantoaxial joint in most patients forms a rational treatment strategy for patients of cervical spondylosis presenting with severe symptoms of myelopathy.

Postoperative Walking Ability of Non-ambulatory Cervical Myelopathy Patients

STUDY DESIGN

A retrospective analysis.

OBJECTIVE

The aim of this study was to clarify the postoperative improvement of walking ability and prognostic factors in nonambulatory patients with cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Many researchers have reported the surgical outcome in compressive cervical myelopathy. However, regarding severe gait disturbance,, it has not been clarified yet how much improvement can be expected.

METHODS

One hundred thirty-one nonambulatory patients with cervical myelopathy were treated surgically and followed for an average of 3 years. Walking ability was graded according to the lower-extremity function subscore (L/E subscore) in Japanese Orthopedic Association score. We divided patients based on preoperative L/E subscores: group A, L/E subscore of 1 point (71 patients); and group B, 0 or 0.5 point (60 patients). The postoperative walking ability was graded by L/E subscore: excellent, ≥2 points; good, 1.5 points; fair, 1 point; and poor, 0.5 or 0 points. We compared preoperative and postoperative scores. The cutoff value of disease duration providing excellent improvement was investigated.

RESULTS

Overall, 50 patients were graded as excellent (38.2%), and 21 patients were graded as good (16.0%). In group B, 17 patients (28.3%) were graded as excellent. Seventeen patients who were graded as excellent had shorter durations of myelopathic symptoms and/or gait disturbance (7.9 and 3.8 months respectively) than the others (29.5 and 8.9 months, respectively) (P < 0.05). Receiver-operating characteristic curve showed that the optimal cutoff values of the duration of myelopathic symptoms and gait disturbance providing excellent improvement were 3 and 2 months, respectively.

CONCLUSION

Even if the patients were nonambulatory, 28.3% of them became able to walk without support after operation. If a patient becomes nonambulatory within 3 months from the onset of myelopathy or 2 months from the onset of gait disturbance, surgical treatment should be performed immediately to raise the possibility to improve stable gait.

LEVEL OF EVIDENCE

3.

Prospective Comparison of Age- and Sex-related Differences in Quantifiable 10-S Grip and Release and 10-S Step Test Results for Diagnosis of Cervical Spondylotic Myelopathy in 454 Patients With Cervical Spondylotic Myelopathy and 818 Asymptomatic Subjects

STUDY DESIGN

A prospective comparison.

OBJECTIVE

The purpose of this prospective study was to verify the clinical effectiveness of the 10-s grip and release (G&R) and 10-s step quantitative tests for assessing the severity of cervical spondylotic myelopathy (CSM) and to compare age- and sex-related differences in the results between large cohorts of CSM patients and asymptomatic subjects.

SUMMARY OF BACKGROUND DATA

To determine the severity of CSM, objective and reproducible means of measuring patient disability are essential. No studies have evaluated differences in quantitative test results between a large series of CSM patients and healthy subjects.

METHODS

Four hundred fifty-four CSM patients and 818 asymptomatic subjects were included. The Japanese subjects were in their 40s to 70s and were divided according to their age by decade. The 10-s G&R and 10-s step tests were used to quantitatively assess performance. The severity of myelopathy before surgery was evaluated according to a scoring system proposed by the Japanese Orthopaedic Association for cervical myelopathy (JOA score) in the CSM patients.

RESULTS

In the CSM patients, the 10-s G&R and step test results significantly correlated with the JOA score (P < 0.0001). The number of the 10-s G&R and step tests significantly decreased with age in both groups. There was a difference in the 10-s G&R and step test results between males and females. In the asymptomatic subjects, the number of the 10-s G&R and step tests in the females was less than that in the males. The numbers in the 10-s G&R and step tests were significantly lower in CSM patients than those in asymptomatic subjects in each decade (P < 0.01).

CONCLUSION

The 10-s G&R and 10-s step tests were useful for quantitatively assessing CSM severity, and age and sex differences in results should be considered in screening.

LEVEL OF EVIDENCE

2.

Magnetic resonance imaging assessment of degenerative cervical myelopathy: a review of structural changes and measurement techniques

Degenerative cervical myelopathy encompasses a spectrum of age-related structural changes of the cervical spine that result in static and dynamic injury to the spinal cord and collectively represent the most common cause of myelopathy in adults. Although cervical myelopathy is determined clinically, the diagnosis requires confirmation via imaging, and MRI is the preferred modality. Because of the heterogeneity of the condition and evolution of MRI technology, multiple techniques have been developed over the years in an attempt to quantify the degree of baseline severity and potential for neurological recovery. In this review, these techniques are categorized anatomically into those that focus on bone, ligaments, discs, and the spinal cord. In addition, measurements for the cervical spine canal size and sagittal alignment are also described briefly. These tools have resulted collectively in the identification of numerous useful parameters. However, the development of multiple techniques for assessing the same feature, such as cord compression, has also resulted in a number of challenges, including introducing ambiguity in terms of which methods to use and hindering effective comparisons of analysis in the literature. In addition, newer techniques that use advanced MRI are emerging and providing exciting new tools for assessing the spinal cord in patients with degenerative cervical myelopathy.

Does age affect surgical outcomes in patients with degenerative cervical myelopathy? Results from the prospective multicenter AOSpine International study on 479 patients

BACKGROUND

In general, older patients with degenerative cervical myelopathy (DCM) are felt to have lower recovery potential following surgery due to increased degenerative pathology, comorbidities, reduced physiological reserves and age-related changes to the spinal cord. This study aims to determine whether age truly is an independent predictor of surgical outcome and to provide evidence to guide practice and decision-making.

METHODS

A total of 479 patients with DCM were prospectively enrolled in the CSM-International study at 16 centres. Our sample was divided into a younger group (<65 years) and an elderly (≥65 years) group. A mixed model analytic approach was used to evaluate differences in the modified Japanese Orthopaedic Association (mJOA), Nurick, Short Form-36 (SF-36) and Neck Disability Index (NDI) scores between groups. We first created an unadjusted model between age and surgical outcome and then developed two adjusted models that accounted for variations in (1) baseline characteristics and (2) both baseline and surgical factors.

RESULTS

Of the 479 patients, 360 (75.16%) were <65 years and 119 (24.84%) were ≥65 years. Elderly patients had a worse preoperative health status (p<0.0001) and were functionally more severe (p<0.0001). The majority of younger patients (64.96%) underwent anterior surgery, whereas the preferred approach in the elderly group was posterior (58.62%, p<0.0001). Elderly patients had a greater number of decompressed levels than younger patients (p<0.0001). At 24 months after surgery, younger patients achieved a higher postoperative mJOA (p<0.0001) and a lower Nurick score (p<0.0001) than elderly patients. After adjustments for patient and surgical characteristics, these differences in postoperative outcome scores decreased but remained significant.

CONCLUSIONS

Older age is an independent predictor of functional status in patients with DCM. However, patients over 65 with DCM still achieve functionally significant improvement after surgical decompression.

Cervical Anterolisthesis: A Predictor of Poor Neurological Outcomes in Cervical Spondylotic Myelopathy Patients After Cervical Laminoplasty

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To clarify the influence of cervical spondylolisthesis on neurological outcomes in cervical spondylotic myelopathy (CSM) patients after cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

Studies focusing on the surgical outcomes in CSM patients with cervical spondylolisthesis are limited.

METHODS

We retrospectively reviewed 125 CSM patients after cervical laminoplasty. Neurological outcomes were evaluated by calculating the Japanese Orthopedic Association (JOA) recovery rate at 2 years after surgery. We defined anterolisthesis as a more than 3-mm anterior vertebral displacement in a flexion radiograph and retrolisthesis as a more than 3-mm posterior vertebral displacement in an extension radiograph. We further assessed potential risk factors for poor neurological outcomes after cervical laminoplasty, including cervical alignment, degree of spinal cord compression, duration of myelopathic symptoms, diabetes mellitus, and preoperative JOA score. Multivariate logistic regression analysis was performed to investigate the risk factors for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty.

RESULTS

Our study included 86 men and 39 women with mean age of 64 (range, 30-89) years. Average JOA scores were 9.9 and 13.3 points before and at 2 years after surgery, respectively. Average recovery rate was 47.2% (range, -68% to 100%), with 62 patients having poor outcomes (JOA recovery rate <50%) at 2 years after surgery. Anterolisthesis and retrolisthesis were observed in 13 and 24 patients, respectively. Multivariate logistic regression analysis revealed that the anterolisthesis was a significant risk factor for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty (P = 0.01), whereas retrolisthesis did not affect the neurological outcomes (P = 0.6).

CONCLUSION

Anterolisthesis, but not retrolisthesis, is a significant risk factor for and predictor of poor neurological outcomes after cervical laminoplasty. Cervical laminoplasty should not be considered in CSM patients with anterolisthesis.

LEVEL OF EVIDENCE

2.

Patient satisfaction with double-door laminoplasty for cervical compression myelopathy

BACKGROUND

Patient satisfaction with posterior laminoplasty for cervical compression myelopathy is not yet established. Moreover, postoperative patient-reported outcomes (PROs) associated with patient satisfaction remain unclear. This study aimed to investigate patient satisfaction after double-door laminoplasty for cervical compression myelopathy, and to identify the postoperative patient-reported outcomes associated with patient satisfaction.

METHODS

This retrospective study included 97 patients with cervical compression myelopathy who underwent double-door laminoplasty between 2002 and 2010 in our institution [mean follow-up: 58 months (range 12-123 months)]. We assessed postoperative PROs from questionnaires administered before surgery and at the latest follow-up. These questionnaires included the Neck Disability Index, physical and mental component summary of Short Form-36, EuroQol-5 dimension, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and a numerical rating scale of pain or numbness in the neck, arms, and scapular lesion. Satisfaction was evaluated on the basis of a seven-point scale. Patients were divided into two groups: satisfied (very satisfied, satisfied, slightly satisfied) and dissatisfied (neither satisfied nor dissatisfied, slightly dissatisfied, dissatisfied, very dissatisfied). All PROs and the effectiveness of surgical treatment assessed by JOACMEQ were compared between both groups.

RESULTS

The satisfied group comprised 69 patients (71 %). Univariate analysis revealed a significant difference in scapular pain, Neck Disability Index, physical component summary of Short Form-36, postoperative mental component summary of Short Form-36, and improvement of lower extremity function postoperatively between both groups. Multivariate analysis revealed that there was a significantly higher proportion of patients with improved lower extremity function in the satisfied group than in the dissatisfied group.

CONCLUSIONS

In conclusion, 71 % of the patients who underwent double-door laminoplasty for cervical compression myelopathy were satisfied. The findings of this study, which examines the association between patient satisfaction and PROs, suggest that improvement in lower extremity function following surgical intervention affects patient satisfaction in those with cervical compression myelopathy.

An outcome measure of functionality and quality of life in patients with cervical myelopathy

Background:

Cervical spondylotic myelopathy (CSM) is a common cause of significant clinical morbidity. The Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) is a measure of health-related quality of life in these patients.

Objectives:

This study aimed to cross-culturally translate and validate the JOACMEQ in Iran.

Patients and Methods:

This study was a prospective clinical validation one. Forward-backward procedure was applied to translate the questionnaire from English into Persian. The translation and cross-cultural adaptation were performed in accordance with the published guidelines. A sample of patients with CSM was asked to respond to the questionnaire at two times: providing preoperative and postoperative assessments (6 months follow-up). To test the reliability, the internal consistency was assessed by Cronbach α coefficient and the validity was assessed by convergent validity. Responsiveness to change was also assessed comparing patients’ preoperative and postoperative scores.

Results:

All 87 patients completed the questionnaire. The Cronbach α coefficient for the JOACMEQ at preoperative and postoperative assessments ranged from 0.71 to 0.82 indicating a good internal consistency for the questionnaire. In addition, the correlation of each item with its hypothesized subscale of the JOACMEQ showed satisfactory results suggesting that the items had a substantial association with their own subscales. Further analysis also indicated that the questionnaire was responsive to change (P < 0.001).

Conclusions:

In general, the findings suggest that the Persian version of the JOACMEQ is a reliable and valid measure of functionality and quality of life evaluation among Iranian patients suffered from CSM.

Translation, cross-cultural adaptation, and validation of a Chinese version of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire

STUDY DESIGN

Translation and psychometric testing of a questionnaire.

OBJECTIVE

To adapt the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) cross-culturally to Chinese language and to investigate the psychometric properties of the translated Chinese JOACMEQ.

SUMMARY OF BACKGROUND DATA

The recently developed JOACMEQ is a self-reported questionnaire used to assess the severity of the cervical spondylotic myelopathy. Despite its acceptance in the literature, the JOACMEQ has not been translated and validated for Chinese-speaking patients.

METHODS

Translation and cross-cultural adaptation of the original JOACMEQ was performed according to published guidelines. A total of 105 patients with a predominant complain of neck pain that included but not limited to patients with a clinically confirmed cervical spondylotic myelopathy were included. Psychometric testing of the responses included construct validity (factor analysis), internal consistency (Cronbach α), test-retest reproducibility (intraclass correlation coefficient), and concurrent validity (Spearman ρ). The discriminatory power of differentiating those with myelopathy from those without was assessed by the area under the receiver operating characteristic curve and with the optimal cutoff points determined.

RESULTS

Construct validity testing revealed a comparable factorial structure of the Chinese JOACMEQ with the original JOACMEQ. The Cronbach α of the Chinese JOACMEQ was 0.88, indicating good internal consistency. Good to excellent test-retest reliability was demonstrated for all 5 domain scores (intraclass correlation coefficient range = 0.79-0.90). A significant strong association between the Chinese Neck Disability Index and the quality of life domain of the Chinese JOACMEQ (Spearman ρ= -0.76, P < 0.01) was identified. The upper and lower extremity function domain scores were found to be significant, with the area under the receiver operating characteristic curve found to be 0.75 (P = 0.04) and 0.82 (P = 0.02), respectively.

CONCLUSION

The results indicated that the Chinese JOACMEQ successfully retained the psychometric properties of the original JOACMEQ and support the usefulness of the Chinese JOACMEQ as an appropriate supplementary diagnostic and outcome measure for Chinese patients suspected of cervical spondylotic myelopathy.

Predictive factors affecting outcome after cervical laminoplasty

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine whether various preoperative factors affect patient outcome after cervical laminoplasty for cervical spondylotic myelopathy (CSM) and/or ossification of posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is a procedure designed to decompress the spinal cord by enlarging the spinal canal while preserving the lamina. Prior research has identified a variety of potential predictive factors that might affect outcomes after this procedure.

METHODS

A systematic search of multiple major medical reference databases was conducted to identify studies explicitly designed to evaluate the effect of preoperative factors on patient outcome after cervical laminoplasty for CSM or OPLL. Studies specifically designed to evaluate potential predictive factors and their associations with outcome were included. Only cohort studies that used multivariate analysis, enrolled at least 20 patients, and adjusted for age as a potential confounding variable were included. JOA (Japanese Orthopaedic Association), modified JOA, and JOACMEQ-L (JOA Cervical Myelopathy Evaluation Questionnaire lower extremity function section) scores were the main outcome measures. Clinical recommendations and consensus statements were made through a modified Delphi approach by applying the GRADE (Grading of Recommendation Assessment, Development and Evaluation)/AHRQ (Agency for Healthcare Research and Quality) criteria.

RESULTS

The search strategy yielded 433 citations, of which 1 prospective and 11 retrospective cohort studies met our inclusion criteria. Overall, the strength of evidence from the 12 studies is low or insufficient for most of the predictive factors. Increased age was not associated with poorer JOA outcomes for patients with CSM, but there is insufficient evidence to make a conclusion for patients with OPLL. Increased severity of disease and a longer duration of symptoms might be associated with JOA outcomes for patients with CSM. Hill-shaped lesions might be associated with poorer JOA outcomes for patients with OPLL. There is insufficient evidence to permit conclusions regarding other predictive factors.

CONCLUSION

Overall, the strength of evidence for all of the predictive factors was insufficient or low. Given that cervical myelopathy due to CSM tends to be progressive and that increased severity of myelopathy and duration of symptoms might be associated with poorer outcomes after cervical laminoplasty for CSM, it is preferable to perform laminoplasty in patients with CSM earlier rather than waiting for symptoms to get worse. Further research is needed to more clearly identify predictive factors that affect outcomes after cervical laminoplasty because there were relatively few studies identified that used multivariate analyses to control for confounding factors and many of these studies did not provide a detailed description of the multivariate analyses or the magnitude of effect estimates. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION 1

For patients with CSM, increased age is not a strong predictor of clinical neurological outcomes after laminoplasty; therefore, age by itself should not preclude cervical laminoplasty for CSM.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Strong.

RECOMMENDATION 2

For patients with CSM, increased severity of disease and a longer duration of symptoms might be associated with poorer clinical neurological outcomes after laminoplasty; therefore, we recommend that patients be informed about this.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Strong. SUMMARY STATEMENTS: For patients with OPLL, hill-shaped lesions might be associated with poorer clinical neurological outcomes after laminoplasty; therefore, surgeons might consider potential benefits and risks of alternative or additional surgery.

A summary of assessment tools for patients suffering from cervical spondylotic myelopathy: a systematic review on validity, reliability and responsiveness

PURPOSE

One of the objectives of this review is to summarize the important features of a good scale. A second aim is to conduct a systematic review to identify scales that can detect the presence of cervical myelopathy and to determine their psychometric properties including validity, reliability and responsiveness.

METHODS

A thorough literature search was performed using MEDLINE, MEDLINE in process, EMBASE, and Cochrane Central Register of Controlled Trials. Articles were included in this study if they compared scale measurements between a control and a myelopathic patient population or if they discussed any psychometric property of a scale.

RESULTS

An ideal scale should be one that is quantifiable, valid, sensitive, responsive and easy to perform, has high inter/intra-rater reliability, internal consistency and a suitable distribution, and is one-dimensional and relevant. In the context of cervical spondylotic myelopathy, it is essential that the scale also addresses the pathophysiology, its key signs and symptoms as well as its natural history. For the systematic review, the search yielded 5,745 citations. Of these, 37 met inclusion criteria, 10 explored the ability of a scale to detect myelopathy, 23 examined validity by assessing correlation between scales, 10 reported reliability, 8 analyzed responsiveness, and 6 discussed internal consistency. The most frequently reported scale was short form-36 (n = 16) followed by Nurick grade (n = 14), Japanese Orthopaedic Association (n = 13), (modified) Japanese Orthopaedic Association (n = 7) and grip and release test (n = 6). Four studies each presented results on the Cooper, Harsh and 30-m walking test.

CONCLUSION

This review summarizes outcome measures used to assess the presence and severity of cervical myelopathy. It includes several validation studies as well as those that have reported the responsiveness and reliability of various measures.

10-second step test for quantitative evaluation of the severity of thoracic compressive myelopathy

STUDY DESIGN

A clinical and cohort study.

OBJECTIVE

To evaluate the efficacy of the 10-second step test as a measure of the severity of thoracic compressive myelopathy.

SUMMARY OF BACKGROUND DATA

Objective measurement is essential for determining the severity of thoracic compressive myelopathy. Some useful measurements for cervical myelopathy have been identified; however, few reports have addressed the measurement of severity of thoracic myelopathy.

METHODS

Twenty-five presurgical patients with thoracic compressive myelopathy were included. Patients with cervical myelopathy and concomitant lumbar canal stenosis were excluded from this analysis. The subjects included 14 males and 11 females, with a mean age of 58.8 years (range, 36-81). The 10-second step test was performed, and the number of steps in 10 seconds was recorded. The Japanese Orthopedic Association (JOA) score for thoracic myelopathy, which was adapted from the JOA score for cervical myelopathy, was also used for assessment.

RESULTS

The average 10-second step test score in all patients was 9.6 ± 1.3 before surgery, which significantly correlated with the total JOA score (r = 0.69, P < 0.01) and its lower extremity motor function score (r = 0.92, P < 0.01). They were retested 12 months after surgery, but the postoperative scores for 5 patients were not available. The average preoperative 10-second step test score of the remaining 20 patients was 9.5 ± 1.5, which significantly improved to 15.1 ± 1.2 12 months after surgery. The step test score in those 20 patients significantly correlated with the total JOA score and lower extremity motor function score before and after surgery (P < 0.01).

CONCLUSION

The 10-second step test reflected the severity of thoracic compressive myelopathy. Moreover, this test was useful for evaluating surgical outcome in patients with thoracic compressive myelopathy.

Tally counter test as a simple and objective assessment of cervical myelopathy

PURPOSE

To test the usefulness of a novel performance test, the tally counter test (counter test), which uses a hand tally counter to objectively assess the severity of cervical myelopathy.

METHODS

Eighty-three patients with compressive cervical myelopathy (mean age 64 ± 13 years) who were undergoing cervical laminoplasty and 280 healthy control subjects (aged 20-89 years) were tested. The subjects were instructed to push the button of a tally counter as many times as possible in 10 s. The average of the right- and left-sided values in each patient was used for analysis. In the patient group, counter test values were compared with Japanese Orthopaedic Association (JOA) and Japanese version of the 36-Item Short Form Health Survey scores preoperatively and 12 months postoperatively.

RESULTS

The average counter test value was significantly lower in patients with myelopathy than age- and gender-matched controls (32.9 ± 10.9 vs. 46.9 ± 8.5, P < 0.0001). The counter test value was significantly higher at 2 weeks postoperatively than preoperatively (P = 0.0014). Counter test values showed a moderate correlation with JOA scores and a weak to moderate correlation with SF-36 physical functioning, role functioning, and role-emotional scores both pre- and postoperatively. The intraclass correlation coefficient of counter test values was high both pre- and postoperatively.

CONCLUSION

The tally counter test is objective and quantitative assessment method for patients with cervical myelopathy. The test is simple, reliable, and capable of detecting small functional changes.

Ultrasonographic quantification of spinal cord and dural pulsations during cervical laminoplasty in patients with compressive myelopathy

PURPOSE

Pulsatile movements of the dura mater have been interpreted as a sign that the cord is free within the subarachnoid space, with no extrinsic compression. However, the association between restoration of pulsation and adequate decompression of the spinal cord has not been established. The present study investigated the relationship between the extent of spinal cord decompression and spinal cord and dural pulsations based on quantitative analysis of intraoperative ultrasonography (US).

METHODS

Eighty-five consecutive patients (55 males, 30 females; mean age, 64 ± 13 years) who underwent cervical double-door laminoplasty to relieve compressive myelopathy were enrolled. Spinal cord decompression status was classified as: Type 1 (non-contact), the subarachnoid space was retained on the ventral side of the cord, Type 2 (contact and apart), the cord showed both contact with and separation from the anterior element of the cervical spine, or Type 3 (contact), the cord showed continuous contact with the anterior element of the cervical spine. Spinal cord and dura mater dynamics were quantitatively analyzed using automatic video-tracking software. Furthermore, the intensity of spinal and dural pulsation was compared with the recovery of motor function at 1 year after surgery as measured by increase in the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ).

RESULTS

Spinal cord pulsation amplitude ranged from 0.01 to 0.84 mm (mean 0.30 ± 0.16 mm) and dural pulsation amplitude ranged from 0.01 to 0.38 mm (mean 0.14 ± 0.08 mm). Average spinal cord pulsation amplitude in Type 2 patients was significantly larger than that in the other groups, whereas, average dural pulsation amplitudes were similar for all three groups. There was a significant correlation between spinal cord and dural pulsation amplitudes in Type 1 patients, but not in Type 2 or Type 3 patients. Type 3 patients showed a particularly poor correlation between spinal cord and dural pulsations. Spinal cord pulsation amplitude was moderately correlated with the recovery of motor function evaluated by JOACMEQ.

CONCLUSION

The present results suggest that restoration of dural pulsation is not an adequate indicator of sufficient decompression of the spinal cord following a surgical procedure.