Factors affecting the surgical results of expansive laminoplasty for cervical spondylotic myelopathy

Are surgical outcomes for one level anterior decompression and fusion associated with MRI parameters for degenerative cervical myelopathy?

Background

Our study is to determine the correlation between preoperative MRI parameters of spinal cord compression and the effects of anterior surgery in patients with degenerative cervical myelopathy (DCM).

Methods

24 normal subjects with no evident abnormalities were selected as group A. 79 patients with DCM underwent single-segment (C4–5/C5–6) ACDF surgery formed the operation group, and separated into group B (without high signal) and group C (with high signal) according to the absence or presence of high signal in the spinal cord on preoperative T2-weighted MRI respectively. MRI parameters (MCC, maximum canal compromise; MSCC, maximum spinal cord compression; CR, spinal cord compression rate; RCSCDS, ratio of cervical spinal cord to dura sac) were measured. The JOA score was used to evaluate cervical spinal cord function and recovery rate (RR) was used to evaluate postoperative efficacy. The relationship between preoperative MRI parameters and postoperative efficacy was analyzed.

Results

The preoperative JOA score and RR of group B were higher than that of group C. MCC and MSCC in group B were significantly lower than those in groups C. The multiple linear regression equation was the fitted postoperative JOA score = 13.371–2.940 * MCC −5.660 * RCSCDS +0.471 * preoperative JOA score. The fitted RR = 1.451–0.472 * MCC −1.313 * RCSCDS.

Conclusion

The occurrence of high signal on T2-weighted images could reflect more serious spinal cord injury. The postoperative JOA score was significantly correlated with MCC, RCSCDS, and preoperative JOA score, while RR was significantly associated with MCC and RCSCDS.

Using a Combined Classification of Increased Signal Intensity on Magnetic Resonance Imaging (MRI) to Predict Surgical Outcome in Cervical Spondylotic Myelopathy

BACKGROUND The aim of this study was to verify whether the combined classification of increased signal intensity (ISI) on magnetic resonance imaging is more closely related to surgical outcomes than signal quality changes or signal longitudinal extent changes alone and to evaluate whether the combined classification ISI method could be used to predict surgical outcomes in cervical spondylotic myelopathy. MATERIAL AND METHODS Eighty-four patients (61 men and 23 women) who underwent surgery for cervical spondylotic myelopathy were included in this retrospective study. The patterns of ISI were classified into 3 categories based on (1) the quality of ISI into Grade 0: none, Grade 1: faint (fuzzy), and Grade 2: intense (sharp); (2) the longitudinal extent of ISI into none, focal, and multisegmental; and (3) the combined classification of the quality and longitudinal extent into Type 1 (none/none), Type 2 (focal/faint), Type 3 (focal/intense), Type 4 (multisegmental/faint), and Type 5 (multisegmental/intense). The multifactorial effects of variables were studied. A stepwise regression analysis was performed to verify whether this combined classification could predict outcome. RESULTS Of the 3 categories, the combined classification type of ISI was most closely related to recovery rate. Stepwise regression analysis confirmed the significance of combined classification of ISI as a predictor for surgical outcome. CONCLUSIONS A combined classification of ISI is more closely related to surgical outcomes than either signal quality changes or signal longitudinal extent changes alone and it could be used as a meaningful indicator for predicting surgical outcomes. We recommend further studies to confirm this finding.

Functional Connectivity Analysis and Prediction of Pain Relief in Association with Spinal Decompression Surgery

BACKGROUND

Although spinal decompression surgery is an effective treatment for myelopathy-induced upper limb pain, some postoperative patients suffer from residual pain in spite of adequate decompression. However, the neural mechanism underlying the poor outcome of pain relief is still unclear. The goal of this study was to explore the brain mechanisms involved in the poor recovery of upper limb pain after the spinal decompression surgery by using functional connectivity (FC) analysis.

METHODS

In this cross-sectional study, 17 patients who underwent cervical spinal decompression surgery were included. Functional MRI (fMRI) during a tactile stimulus for each hand was performed at 1 day before and 7 days after the surgery. In total, 34 fMRI scans (17 left and right upper limbs, respectively) were obtained before and after the surgery, respectively. The patients were divided into poor-recovery and good-recovery groups, and then we searched for the FC that was related to poor-recovery.

RESULTS

The poor-recovery group (n = 15) showed significantly stronger connectivity between the postcentral gyrus (postCG) and dorsolateral prefrontal cortex (DLPFC) than the good-recovery group (n = 12) preoperatively. When the cutoff value of the preoperative FC between the left postCG and right middle frontal gyrus included in DLPFC was >0.17, the sensitivity and specificity for poor recovery were 73% and 75%, respectively.

CONCLUSIONS

Our study showed that FC between the postCG and DLPFC may be a predictor of pain relief. This result suggested that assessing FC can lead to more informed surgical interventions for cervical spondylotic myelopathy.

Degenerative Cervical Myelopathy: How to Identify the Best Responders to Surgery?

Surgery is the only definitive treatment for degenerative cervical myelopathy (DCM), however, the degree of neurological recovery is often unpredictable. Here, we assess the utility of a multidimensional diagnostic approach, consisting of clinical, neurophysiological, and radiological parameters, to identify patients likely to benefit most from surgery. Thirty-six consecutive patients were prospectively analyzed using the modified Japanese Orthopedic Association (mJOA) score, MEPs/SSEPs and advance and conventional MRI parameters, at baseline, and 3- and 12-month postoperatively. Patients were subdivided into “normal” and “best” responders (<50%, ≥50% improvement in mJOA), and correlation between Diffusion Tensor Imaging (DTI) parameters, mJOA, and MEP/SSEP latencies were examined. Twenty patients were “best” responders and 16 were “normal responders”, but there were no statistical differences in age, T2 hyperintensity, and midsagittal diameter between them. There was a significant inverse correlation between the MEPs central conduction time and mJOA in the preoperative period (p = 0.0004), and a positive correlation between fractional anisotropy (FA) and mJOA during all the phases of the study, and statistically significant at 1-year (r = 0.66, p = 0.0005). FA was significantly higher amongst “best responders” compared to “normal responders” preoperatively and at 1-year (p = 0.02 and p = 0.009). A preoperative FA > 0.55 was predictor of a better postoperative outcome. Overall, these results support the concept of a multidisciplinary approach in the assessment and management of DCM.

Degenerative Cervical Myelopathy in Higher-Aged Patients: How Do They Benefit from Surgery?

Background: Degenerative cervical myelopathy (DCM) is the most common reason for spinal cord disease in elderly patients. This study analyzes the preoperative status and postoperative outcome of higher-aged patients in comparison to young and elderly patients in order to determine the benefit to those patients from DCM surgery. Methods: A retrospective analysis of the clinical data, radiological findings, and operative reports of 411 patients treated surgically between 2007 and 2016 suffering from DCM was performed. The preoperative and postoperative neurological functions were evaluated using the modified Japanese Orthopedic Association Score (mJOA Score), the postoperative mJOA Score improvement, the neurological recovery rate (NRR) of the mJOA Score, and the minimum clinically important difference (MCID). The Charlson Comorbidity Index (CCI) was used to evaluate the impact of comorbidities on the preoperative and postoperative mJOA Score. The comparisons were performed between the following age groups: G1: ≤50 years, G2: 51–70 years, and G3: >70 years. Results: The preoperative and postoperative mJOA Score was significantly lower in G3 than in G2 and G1 (p < 0.0001). However, the mean mJOA Score’s improvement did not differ significantly (p = 0.81) between those groups six months after surgery (G1: 1.99 ± 1.04, G2: 2.01 ± 1.04, G: 2.00 ± 0.91). Furthermore, the MCID showed a significant improvement in every age-group. The CCI was evaluated for each age-group, showing a statistically significant group effect (p < 0.0001). Analysis of variance revealed a significant group effect on the delay (weeks) between symptom onset and surgery (p = 0.003). The duration of the stay at the hospital did differ significantly between the age groups (p < 0.0001). Conclusion: Preoperative and postoperative mJOA Scores, but not the extent of postoperative improvement, are affected by the patients’ age. Therefore, patients should be considered for DCM surgery regardless of their age.

Assessment of degenerative cervical stenosis on T2-weighted MR imaging: sensitivity to change and reliability of mid-sagittal and axial plane metrics

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

To assess the sensitivity to change and reliability of various mid-sagittal and axial plane metrics in the assessment of patients with single-level degenerative cervical stenosis on T2-weighted MR imaging.

SETTING

A diagnostic MR imaging facility in Sydney (Australia).

METHODS

We retrospectively reviewed T2-weighted MR images of 85 consecutive patients (48 M and 37 F) with single-level degenerative cervical stenosis. Canal compromise and cord compression were evaluated using three mid-sagittal plane metrics (M₁, M₂, and M₃) and two axial plane metrics (M₄ and M₅), at the level of stenosis and nonstenotic cephalad and caudal levels (controls). Sensitivity to change (SC) for each metric was evaluated as the percentage deviation of the measured value from the estimated normal value based on cephalad and caudal controls. Reliability for each metric was evaluated using intraclass correlation coefficients.

RESULTS

Degenerative cervical stenosis showed a bimodal distribution peaking at C5-6 (n = 32) and C3-4 (n = 29) levels. The changes in the canal and cord geometry along the rostrocaudal axis were inconsistent. Across all individual subjects (reflecting a range of stenosis severity), M₃ (-32.87% ± 10.60%) was more sensitive to change compared with M₁ (16.64% ± 16.48%) and M₂ (-23.95% ± 11.12%). Similarly, M₄ (-24.62% ± 12.17%) was more sensitive to change compared with M₅ (-6.71% ± 11.08%). The level of reliability was "moderate" to "excellent" for mid-sagittal plane measurements, and "poor" to "excellent" for axial plane measurements.

CONCLUSION

Changes in canal dimensions in the mid-sagittal plane and cord shape in the axial plane are sensitive indicators of degenerative cervical stenosis on T2-weighted MR images.

Neurological Recovery Pattern in Cervical Spondylotic Myelopathy after Anterior Surgery: A Prospective Study with Literature Review

Study Design

Prospective clinical study.

Purpose

The present study aimed to examine the neurological recovery pattern in cervical spondylotic myelopathy (CSM) after anterior cervical decompression and compare it with the existing reports in the literature.

Overview of Literature

Neurological recovery and regression of myelopathy symptoms is an important factor that determines the outcomes of surgical decompression. The present findings contribute to the literature on the pattern of neurological recovery and patient prognosis with respect to the resolution of myelopathy symptoms after surgery.

Methods

This prospective study was conducted in Government Medical College in Jammu, North India between November 2012 and October 2014, a total of 30 consecutive patients with CSM were included and treated with anterior decompression and stabilization. They were prospectively followed up for 1 year and were evaluated for their neurological recovery pattern. The postoperative outcome was evaluated using the modified Japanese Orthopaedic Association (mJOA) score. The recovery rate was calculated using Hirabayashi’s method. The JOA score was assessed before the operation and postoperatively at 1 week, 2 weeks, 1 month, 3 months, 4 months, 6 months, and 1 year.

Results

The postoperative mJOA score was 0 in the 1st month, 12.90±3.57 in the 3rd month, 13.50±3.55 in the 4th month, 14.63±3.62 in the 6th month, and 14.9±3.24 at the final follow-up of 1 year. The average recovery rate during the 1st month follow-up was 0%, and that during the 3rd month follow-up was 12.91% with a range of 0%–50%. The average recovery rate during the 4th month was 32.5%, with a range of 0%–60%, while that during the 6th month was 72.83%, with a range of 0%–100%. The average recovery rate during the final follow-up of 1 year was 54.3%.

Conclusions

Neurological recovery after surgical decompression starts from the 3rd postoperative month and progresses until the 6th postoperative month; thereafter, it gradually plateaus over the subsequent 6 months until it steadies. Symptom duration is an important factor that requires consideration while determining postoperative neurological recovery.

Prospective Analysis of Functional Outcome of Single-Stage Surgical Treatment for Symptomatic Tandem Spinal Stenosis

BACKGROUND

Tandem spinal stenosis (TSS) is a rare presentation leading to combined clinical features of upper motor neuron and lower motor neuron lesion which includes intermittent neurogenic claudication with or without neurological deficit, progressive gait imbalance and gait disturbances. In literature, there is controversy whether stage surgery or single-stage surgery should be done.

MATERIALS AND METHODS

From June 2009 to November 2016 in a series of 1381 patients who underwent surgery for various degenerative spinal conditions, 82 patients were diagnosed with having symptomatic TSS with an incidence of 5.93%. All patients diagnosed with TSS underwent single-stage surgical intervention by one surgical team. The perioperative factors were recorded for each patient. All patients were evaluated preoperatively and postoperatively at each followup with the modified Japanese Orthopaedic Association (mJOA) score, Nurick's grading, Oswestry disability index (ODI) and Cooper scale.

RESULTS

In this study, 82 patients including 70 males and 12 females underwent simultaneous surgical intervention for symptomatic TSS. The mean age of patients was 61.78 ± 10.48 years. There was a significant improvement in mJOA score, Nuricks grading, ODI and Coopers scale postoperatively as compared to preoperative values (P < 0.05).

CONCLUSION

Symptomatic TSS can be safely managed by single-stage surgical intervention with good postoperative results or without a significant increase in complication rates. Single-stage surgical intervention helps to relieve the symptoms of both cervical and lumbar spinal cord compression, avoids the risk of repeated anesthesia, reduce the duration of surgery, repeated hospitalization hence, reducing the cost for hospitalization and also reducing the rehabilitation, recuperation time and early functional recovery justifies single-stage surgical intervention.

Value of conventional MRI and diffusion tensor imaging parameters in predicting surgical outcome in patients with degenerative cervical myelopathy

BACKGROUND

In addition to conventional magnetic resonance imaging (cMRI), diffusion tensor imaging (DTI) has been investigated as a potential diagnostic and prognostic tool for patients with degenerative cervical myelopathy (DCM).

OBJECTIVE

To assess the efficacy of cMRI and DTI parameters in prediction of surgical outcome in DCM patients.

METHODS

One hundred and forty-two patients with DCM who underwent presurgical cMRI and DTI of the cervical spine were included. Quantitative parameters obtained by cMRI included compression ratio (CR), transverse area (TA), and signal intensity ratio (SIR). DTI was evaluated for apparent diffusion coefficient (ADC) and fractional anisotropy (FA). The Japanese Orthopaedic Association (JOA) score and recovery rate were used to evaluate clinical outcomes. A JOA recovery rate < 50% was defined as a poor surgical outcome. The relationship of surgical outcome with various imaging parameters was examined. Receiver operating characteristic (ROC) curves were used to measure the predictive ability and determine the best cut-off values of the quantitative parameters.

RESULTS

By ROC curve analyses of imaging parameters, the largest area under the ROC curve (AUC) was for FA (0.750), followed by ADC (0.719), TA (0.716), SIR (0.673), and CR (0.591). The cut-off values with the best compromise between sensitivity and specificity were set at 0.390 for FA, 1.344 × 10-3 mm2/s for ADC, 46.02 mm2 for TA, 1.556 for SIR, and 26.56% for CR. Multivariate logistic regression model revealed that JOA score ⩽ 8 points, TA ⩽ 46.02 mm2, and FA ⩽ 0.390 were independently associated with poor surgical outcome. The AUC value for the three-predictor model was 0.871, indicating strong predictive discrimination, and was significantly higher than the AUC value for the model containing only the JOA score (0.763; P= 0.003).

CONCLUSIONS

JOA score is a reasonable predictor of surgical outcome in DCM. However, a model inclusive of TA and FA provides superior predictive ability. Thus, quantitative analysis of cMRI and DTI is useful for predicting surgical outcome in DCM.

Spinal cord MRI signal changes at 1 year after cervical decompression surgery is useful for predicting midterm clinical outcome: an observational study using propensity scores

BACKGROUND CONTEXT

There is little information on the relationship between magnetic resonance imaging (MRI) T2-weighted high signal change (T2HSC) in the spinal cord and surgical outcome for cervical myelopathy. We therefore examined whether T2HSC regression at 1 year postoperatively reflected a 5-year prognosis after adjustment using propensity scores for potential confounding variables, which have been a disadvantage of earlier observational studies.

PURPOSE

The objective of this study was to clarify the usefulness of MRI signal changes for the prediction of midterm surgical outcome in patients with cervical myelopathy.

STUDY DESIGN/SETTING

This is a retrospective cohort study.

PATIENT SAMPLE

We recruited 137 patients with cervical myelopathy who had undergone surgery between 2007 and 2012 at a median age of 69 years (range: 39-87 years).

OUTCOME MEASURES

The outcome measures were the recovery rates of the Japanese Orthopaedic Association (JOA) scores and the visual analog scale (VAS) scores for complaints at several body regions.

MATERIALS AND METHODS

The subjects were divided according to the spinal MRI results at 1 year post surgery into the MRI regression group (Reg+ group, 37 cases) with fading of T2HSC, or the non-regression group (Reg- group, 100 cases) with either no change or an enlargement of T2HSC. The recovery rates of JOA scores from 1 to 5 years postoperatively along with the 5-year postoperative VAS scores were compared between the groups using t test. Outcome scores were adjusted for age, sex, diagnosis, symptom duration, and preoperative JOA score by the inverse probability weighting method using propensity scores.

RESULTS

The mean recovery rates in the Reg- group were 35.1%, 34.6%, 27.6%, 28.0%, and 30.1% from 1 to 5 years post surgery, respectively, whereas those in the Reg+ group were 52.0%, 52.0%, 51.1%, 49.0%, and 50.1%, respectively. The recovery rates in the Reg+ group were significantly higher at all observation points. At 5 years postoperatively, the VAS score for pain or numbnessin the arms or hands of the patients in the Reg+ group (24.7 mm) was significantly milder than that of the patients in the Reg- group (42.2 mm).

CONCLUSIONS

Spinal T2HSC improvement at 1 year postoperatively may predict a favorable recovery until up to 5 years after surgery.

The value of preoperative magnetic resonance imaging in predicting postoperative recovery in patients with cervical spondylosis myelopathy: a meta-analysis

This meta-analysis was designed to elucidate whether preoperative signal intensity changes could predict the surgical outcomes of patients with cervical spondylosis myelopathy on the basis of T1-weighted and T2-weighted magnetic resonance imaging images. We searched the Medline database and the Cochrane Central Register of Controlled Trials for this purpose and 10 studies meeting our inclusion criteria were identified. In total, 650 cervical spondylosis myelopathy patients with (+) or without (-) intramedullary signal changes on their T2-weighted images were examined. Weighted mean differences and 95% confidence intervals were used to summarize the data. Patients with focal and faint border changes in the intramedullary signal on T2 magnetic resonance imaging had similar Japanese Orthopaedic Association recovery ratios as those with no signal changes on the magnetic resonance imaging images of the spinal cord did. The surgical outcomes were poorer in the patients with both T2 intramedullary signal changes, especially when the signal changes were multisegmental and had a well-defined border and T1 intramedullary signal changes compared with those without intramedullary signal changes. Preoperative magnetic resonance imaging including T1 and T2 imaging can thus be used to predict postoperative recovery in cervical spondylosis myelopathy patients.

The diagnostic value of magnetic resonance imaging measurements for assessing cervical spinal canal stenosis

OBJECT

The authors investigated the relevance of 2D MRI measurements for the diagnosis of critical cervical spinal canal stenosis. Among patients who had sustained a minor cervical spine trauma, they compared MRI measurements of the cervical spine between those with acute cervical spinal cord injury (CSCI) and those without. They also investigated the correlation between the MRI measurements and the severity of CSCI as well as classification accuracy concerning the diagnosis of critical spinal canal stenosis for acute CSCI after a minor trauma.

METHODS

The authors conducted a single-center retrospective radiological case-control study of patients who had sustained CSCI after a minor trauma to the cervical spine from January 2000 to August 2010. The controls were patients who had sustained a cervical trauma without clinical or radiological signs of cervical spinal cord pathology.

On axial T2-weighted MR images, the following were measured: the transverse spinal canal and cord area, the transverse and sagittal cord diameter, and the sagittal canal diameter of the cervical spine (C3–7). Using these measurements, the authors calculated the cord-canal-area ratio by dividing the transverse cord area by the transverse canal area, the space available for the cord by subtracting the sagittal canal diameter from the sagittal cord diameter, and the compression ratio by dividing the transverse cord diameter by its sagittal diameter.

The severity of CSCI was assessed by using the motor index scores of 10 key muscles at different time points (initially, 1, 3, and 12 months after injury) obtained from the clinical records.

The intra- and interobserver reliability of the MRI measurements, intra- and intergroup differences, and correlations between variables were also investigated. Receiver operating characteristic curves were calculated for evaluating the classification accuracy of the imaging variables for CSCI.

RESULTS

Data for 52 CSCI patients and 77 control patients were analyzed. The intra- and interobserver reliability regarding the MRI measurements ranged from good (0.72) to perfect (0.99). Differences between the CSCI group and the control group were significant (p < 0.001) for all parameters, except for the cord area. The most prominent differences between the groups existed for the spinal canal area, cord-canal-area ratio, and space available for the cord. The classification accuracy was best for the cord-canal-area ratio and the space available for the cord; areas under the curve were 0.99 (95% CI 0.97–1.0) and 0.98 (95% CI 0.95–0.99), respectively. There was no significant (p > 0.05) correlation between any of the imaging parameters and the motor index score at any time point.

CONCLUSIONS

The cord-canal-area ratio (> 0.8) or the space available for the cord (< 1.2 mm) measured on MR images can be used to reliably identify patients at risk for acute CSCI after a minor trauma to the cervical spine. However, there does not seem to be any association between spinal canal imaging characteristics and the severity of or recovery from CSCI after a minor trauma.

Do quantitative magnetic resonance imaging parameters correlate with the clinical presentation and functional outcomes after surgery in cervical spondylotic myelopathy? A prospective multicenter study

STUDY DESIGN

A prospective multicenter cohort study.

OBJECTIVE

To establish the relationship between preoperative quantitative magnetic resonance imaging (MRI) parameters and clinical presentation and postoperative outcomes in patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Correlation of magnetic resonance imaging with clinical presentation and outcomes in cervical spondylotic myelopathy is poorly understood.

METHODS

A total of 134 magnetic resonance imaging scans were reviewed from 12 sites across North America. The transverse area (TA) of the spinal cord at the site of maximal compression was computed, and spinal cord signal intensity (SI) changes on T1-/T2-weighted imaging (WI) were evaluated. Detailed clinical assessments--neurological signs, symptoms, Nurick grade, modified Japanese Orthopaedic Association, segmental-tract score, and long-tract score of modified Japanese Orthopaedic Association, 30-m walk test, Short-Form 36 questionnaire, and neck disability index were performed at admission, 6 months, and 12 months postoperatively.

RESULTS

The total number of neurological signs in a patient correlated with TA (P = 0.01) and SI changes on T1-/T2WI (P = 0.05). Pre- and postoperative Nurick grade (P = 0.03, P = 0.02), modified Japanese Orthopaedic Association score (P = 0.005, P = 0.001), segmental-tract score (P = 0.05, P = 0.006), and long-tract score (P = 0.006, P = 0.002), 30-m walk test (P = 0.002, P = 0.01) correlated with TA. There was no significant difference in pre- and postoperative clinical scores in patients with/without SI changes. Patients with severe cord compression showed SI changes on T1-/T2WI more frequently (r =-0.27, r =-0.38). Pyramidal signs--plantar response, Hoffmann reflex and hyper-reflexia correlated with TA (P = 0.003, P = 0.0004, P = 0.024, respectively) and SI changes on T1/T2WI (P = 0.02).

CONCLUSION

TA closely mirrors the clinical presentation of cervical spondylotic myelopathy and may be used in predicting surgical outcomes. Pyramidal signs correlated with TA and/or SI changes on T1-/T2WI. The total number of neurological signs in a patient correlated with TA. There was no significant relationship between TA, age and duration of symptoms.

LEVEL OF EVIDENCE

3.

Is diffusion anisotropy a biomarker for disease severity and surgical prognosis of cervical spondylotic myelopathy?

PURPOSE

To explore the value of diffusion-tensor (DT) imaging in addressing the severity of cervical spondylotic myelopathy (CSM) and predicting the outcome of surgical treatment.

MATERIALS AND METHODS

From July 2009 to May 2012, 65 volunteers were recruited for this institutional review board-approved study, and all gave informed consent; 20 volunteers were healthy subjects (age range, 41-62 years), and 45 were patients with CSM (age range, 43-86 years). Anatomic and DT 3.0-T magnetic resonance images were obtained. Surgical decompression was performed in 22 patients with CSM, and patients were followed up for 6 months to 2 years. The clinical severity of myelopathy and postoperative recovery were assessed by using the modified Japanese Orthopaedic Association (mJOA) score. A recovery ratio (comparison of postoperative with preoperative mJOA score) of more than 50% indicated a good clinical outcome of surgery. DT findings, patient age, T2 high signal intensity (HSI), and somatosensory evoked potential (SEP) were analyzed by using a logistic regression model to predict the surgical outcome of patients with CSM.

RESULTS

A significant difference in cervical cord mean fractional anisotropy (FA) was found between healthy subjects and patients with CSM (0.65 ± 0.05 [standard deviation] vs 0.52 ± 0.13, P < .001). FA values were significantly correlated with the severity of neurologic dysfunction indicated by mJOA score (r(2) = 0.327, P = .016). Logistic regression analysis showed that mean FA (P = .030) and FA at the C2 vertebra (P = .035) enabled prediction of good surgical outcome; however, preoperative mJOA (P = .927), T2 HSI (P = .176), SEP amplitude (P = .154), and latency (P = .260) did not.

CONCLUSION

FA is a biomarker for the severity of myelopathy and for subsequent surgical outcome.

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.

Assessment of spinal cord compression by magnetic resonance imaging--can it predict surgical outcomes in degenerative compressive myelopathy? A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

We sought to conduct a systematic review to examine the role of magnetic resonance imaging in predicting outcomes after surgery and to evaluate the evidence currently available critically.

SUMMARY OF BACKGROUND DATA

Degenerative compressive myelopathy is a common clinical problem associated with adverse health outcomes. Although a number of studies have investigated the association between preoperative magnetic resonance imaging characteristics and outcomes after surgery for degenerative compressive myelopathy, the conclusions of these studies have often yielded differing results.

METHODS

Articles examining the predictive value of magnetic resonance imaging were obtained from MEDLINE, EMBASE, and PubMed databases (1980-2011). Thirty publications that met the inclusion criteria were reviewed. Two reviewers independently assessed each study regarding the level of evidence (using the criteria proposed by Sackett) and methodological quality based on revised Cochrane quality assessment checklist.

RESULTS

Three excellent, 1 good, and 10 poor quality studies assessed cord compression--transverse area (4), compression ratio (5), and anteroposterior diameter (1). Relationship between signal intensity (SI) changes and surgical outcomes were reviewed by 28 studies--8 excellent, 9 good, and 13 poor quality studies. SI changes within the spinal cord included the presence of SI on T2-weighted image (WI) (17), area of SI on T2WI (8), degree of SI on T2WI (5), presence of SI on both T1-/T2WI (2), SI ratio on T2WI (2), and the position of SI on T2WI (1).

CONCLUSION

Based on a combination of excellent and good quality studies, transverse area correlates with recovery ratio but not with postoperative functional score assessed by Japanese Orthopaedic Association/modified Japanese Orthopaedic Association scores. SI changes defined by (1) its presence on T2WI, (2) its extent (focal or multisegmental), (3) its brightness, and (4) its presence on both T1-/T2WI can predict surgical outcomes in degenerative compressive myelopathy.

Laminoplasty and laminectomy for cervical sponydylotic myelopathy: a systematic review

BACKGROUND

Cervical spondylotic myelopathy is frequently encountered in neurosurgical practice. The posterior surgical approach includes laminectomy and laminoplasty.

OBJECTIVE

To perform a systematic review evaluating the effectiveness of posterior laminectomy compared with posterior laminoplasty for patients with cervical spondylotic myelopathy.

METHODS

An extensive search of the literature in Pubmed, Embase, and Cochrane library was performed by an experienced librarian. Risk of bias was assessed by two authors independently. The quality of the studies was graded, and the following outcome measures were retrieved: pre- and postoperative (m)JOA, pre- and postoperative ROM, postoperative VAS neck pain, and Ishira cervical curvature index. If possible data were pooled, otherwise a weighted mean was calculated for each study and a range mentioned.

RESULTS

All studies were of very low quality. Due to inadequate description of the data in most articles, pooling of the data was not possible. Qualitative interpretation of the data learned that there were no clinically important differences, except for the higher rate of procedure-related complications with laminoplasty.

CONCLUSION

Based on these results, a claim of superiority for laminoplasty or laminectomy was not justified. The higher number of procedure-related complications should be considered when laminoplasty is offered to a patient as a treatment option. A study of robust methodological design is warranted to provide objective data on the clinical effectiveness of both procedures.

Predictors of surgical outcome in cervical spondylotic myelopathy

STUDY DESIGN

Prospective study.

OBJECTIVE

To determine whether magnetic resonance imaging and clinical and demographic findings in patients with cervical spondylotic myelopathy (CSM) were independently associated with baseline functional scores and whether these were also predictive of postoperative functional outcomes.

SUMMARY OF BACKGROUND DATA

There are considerable limitations in current literature that prevent making formal recommendations regarding the use of clinical and radiological prognostic factors in patients with CSM.

METHODS

This prospective study included 65 consecutive patients with CSM treated in a tertiary referral center. The modified Japanese Orthopaedic Association (mJOA) scale was used to quantify disability at admission and at 12-month follow-up. Age, sex, duration of symptoms, severity of myelopathy, spinal column alignment, surgical technique, levels of compression, anteroposterior diameter and transverse area at the site of maximal cord compression, and magnetic resonance imaging signal intensity changes were assessed. Data were analyzed using Spearman rank correlation test, analysis of variance, Mann-Whitney U test, and stepwise multivariate regression.

RESULTS

Higher baseline mJOA scores were associated with younger age (P = 0.0002), shorter duration of symptoms (P = 0.03), and greater transverse area (P = 0.02). Better recovery ratio was associated with younger age (P = 0.005) and higher baseline mJOA score (P = 0.003). Greater changes in mJOA score were associated with higher baseline mJOA score (P < 0.0001). Using multivariate analysis, the functional outcomes after surgery were best predicted by baseline mJOA score and age of patient.

CONCLUSION

Age and baseline mJOA scores were highly predictive of outcome for patients undergoing surgical treatment of CSM. The degree of spinal cord compression and patterns of signal intensity changes on T1/T2 weighted images were not independently predictive of outcome, but it was found to correlate with the functional status at the time of presentation and age of the patient. The duration of symptoms correlated well with preoperative functional status but did not seem to affect the postoperative outcome.

Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review

PURPOSE

To conduct a systematic review of the literature to determine important clinical predictors of surgical outcome in patients with cervical spondylotic myelopathy (CSM).

METHODS

A literature search was performed using MEDLINE, MEDLINE in Process, EMBASE and Cochrane Database of Systematic Reviews. Selected articles were evaluated using a 14-point modified SIGN scale and classified as either poor (<7), good (7-9) or excellent (10-14) quality of evidence. For each study, the association between various clinical factors and surgical outcome, evaluated by the (modified) Japanese Orthopaedic Association scale (mJOA/JOA), Nurick score or other measures, was defined. The results from the EXCELLENT studies were compared to the combined results from the EXCELLENT and GOOD studies which were compared to the results from all the studies.

RESULTS

The initial search yielded 1,677 citations. Ninety-one of these articles, including three translated from Japanese, met the inclusion and exclusion criteria and were graded. Of these, 16 were excellent, 38 were good and 37 were poor quality. Based on the excellent studies alone, a longer duration of symptoms was associated with a poorer outcome evaluated on both the mJOA/JOA scale and Nurick score. A more severe baseline score was related with a worse outcome only on the mJOA/JOA scale. Based on the GOOD and EXCELLENT studies, duration of symptoms and baseline severity score were consistent predictors of mJOA/JOA, but not Nurick. Age was an insignificant predictor of outcome on any of the functional outcomes considered.

CONCLUSION

The most important predictors of outcome were preoperative severity and duration of symptoms. This review also identified many other valuable predictors including signs, symptoms, comorbidities and smoking status.

Reliability of quantitative magnetic resonance imaging methods in the assessment of spinal canal stenosis and cord compression in cervical myelopathy

STUDY DESIGN

Prospective, blinded reliability study of quantitative magnetic resonance imaging (MRI) measures in patients with cervical myelopathy.

OBJECTIVE

To assess the intra- and interobserver reliability of commonly used quantitative MRI measures such as transverse area (TA) of spinal cord, compression ratio (CR), maximum canal compromise (MCC), and maximum spinal cord compression (MSCC).

SUMMARY OF BACKGROUND DATA

There is no consensus on an optimal quantitative MRI method(s) in assessing canal stenosis and cord compression.

METHODS

Seven surgeons performed measurements on 17 digital MR images, on 4 separate occasions. The degree of stenosis was evaluated by measuring TA and CR on axial T2, MCC, and MSCC on midsagittal T1- and T2-weighted MRI sequences, respectively. Statistical analyses included repeated-measures analysis of variance and intraclass correlation coefficients (ICCs).

RESULTS

The mean ± SD for intraobserver ICC was 0.88 ± 0.1 for MCC, 0.76 ± 0.08 for MSCC, 0.92 ± 0.07 for TA, and 0.82 ± 0.13 for CR. In addition, the interobserver ICC was 0.75 ± 0.04 for MCC, 0.79 ± 0.09 for MSCC, 0.80 ± 0.05 for CR, and 0.86 ± 0.03 for TA. Higher degree of canal compromise (MCC) was associated with lower modified version of Japanese Orthopaedic Association Scale score (P = 0.05). Also, a strong association was found between MSCC and lower modified version of Japanese Orthopaedic Association Scale score, greater number of steps, and longer walking time (P < 0.05).

CONCLUSION

All 4 measurement techniques demonstrated a good to moderately high degree of intra- and interobserver reliability. Highest reliability was noted in the assessment of T2-weighted sequences and axial MRI. Our results show that the measurements of MCC, MSCC, and CR are sufficiently reliable and correlate well with clinical severity of cervical myelopathy.

Neurogenic bladder associated with pure cervical spondylotic myelopathy: clinical characteristics and recovery after surgery

STUDY DESIGN

Retrospective study.

OBJECTIVE

To examine the prevalence of lower urinary tract symptoms (LUTS) and neurogenic bladder (NB), and surgical outcomes in pure cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

The inclusion of various types of cervical diseases, NB, and no obvious definition of NB provided the wide range of NB prevalence frequency among previous reports.

METHODS

Of the 220 operated patients with cervical myelopathy, 54 were selected by excluding other cervical and/or concomitant diseases contributing to LUTS. All patients with LUTS were referred to urologists and recommended to undergo urodynamic study (UDS). The presence of NB was judged by abnormal findings of UDS according to the most recent criteria and a congruity between LUTS and the course of cervical myelopathy. Patients were divided into 4 groups: no symptoms, positive symptoms without UDS examination, positive symptoms with positive NB, and positive symptoms with negative NB. Evaluation scores were compared among the groups before and after surgery.

RESULTS

There were no particular LUTS in NB patients. Prevalence of LUTS was 53.7% and that of NB was at least 20.4% in the patients with pure cervical spondylotic myelopathy. The scores of all 4 groups improved after surgery (P < 0.05); however, the recovery rate of NB group (47.1%) was the worst among the groups (no-symptoms group, 69.3%; negative-NB group, 53.5%; and positive symptoms without UDS group, 57.1%). Preoperative part scores showed no difference among the groups, whereas NB group demonstrated lower scores in finger and lower extremity postoperatively. A post hoc analysis confirmed a significantly poorer recovery rate related to the NB group only in the lower extremities.

CONCLUSION

This study is the first to describe the prevalence of LUTS and NB according to the most recent criteria in patients with pure cervical spondylotic myelopathy, which demonstrated that neurological functions in NB patients may recover; however, the extent will be limited to two-thirds of those in patients with no-NB; moreover, the remaining symptoms derive from poor lower limb function.

Cervical spondylotic myelopathy: the clinical phenomenon and the current pathobiology of an increasingly prevalent and devastating disorder

Cervical spondylotic myelopathy (CSM) is a common disorder involving chronic progressive compression of the cervical spinal cord due to degenerative disc disease, spondylosis, or other degenerative pathology. CSM is the most common form of spinal cord impairment and causes functional decline leading to reduced independence and quality of life. Despite a sound understanding of the disease process, clinical presentation and management, a universal definition of CSM and a standardized index of severity are not currently used universally. Work is required to develop a definition and establish clinical predictors of progression to improve management of CSM. Despite advances in decompressive and reconstructive surgery, patients are often left with residual disability. Gaps in knowledge of the pathobiology of CSM have limited therapeutic advances to complement surgery. Although the histopathologic and pathophysiologic similarities between CSM and traumatic spinal cord injury have long been acknowledged, the unique pathomechanisms of CSM remain unexplored. Increased efforts to elucidate CSM pathobiology could lead to the discovery of novel therapeutic targets for human CSM and other spinal cord diseases. Here, the natural history of CSM, epidemiology, clinical presentation, and current methods of clinical management are reported, along with the current state of basic scientific research in the field.

Surgical outcomes and prognostic factors of cervical spondylotic myelopathy in diabetic patients

BACKGROUND

There have been a few reports on the surgical outcomes of cervical myelopathy in diabetic patients; however, those studies included ossification of the posterior longitudinal ligament. This study investigated whether surgical outcome of expansive laminoplasty (ELAP) for diabetic patients with cervical spondylotic myelopathy (CSM) differs from that for non-diabetic patients and determined prognostic factors in diabetic patients.

METHODS

We retrospectively reviewed 78 patients with CSM after excluding the cases with other medical conditions, which could affect surgical outcome from 222 consecutive patients who had undergone ELAP between 2000 and 2008 in our hospital. The patients were divided into two groups: diabetic patients (Group 1) and non-diabetic patients (Group 2). We evaluated differences in age, gender, pre- and postoperative Japanese Orthopaedic Association (JOA) score, recovery rate (RR), symptom duration, and postoperative complications between the two groups. In Group 1, the correlation between RR and factors indicating the severity of diabetes mellitus was assessed.

RESULTS

There were 13 patients in Group 1 and 65 in Group 2. There was no significant difference in age, gender, JOA score before or after surgery, or symptom duration between the two groups. Group 1 showed poorer recovery of sensory and motor function in the lower extremities. A negative correlation was observed between RR and the preoperative hemoglobin A(1c) (HbA(1c)) level in Group 1.

CONCLUSIONS

Diabetic patients experienced benefits from ELAP similar to non-diabetic patients. A negative correlation between RR and preoperative HbA(1c) level suggests that strict blood sugar control is recommended before surgery.

Cervical myelopathy due to single level prolapsed disc and spondylosis: a comparative study on outcome between two groups

This article describes a retrospective study on myelopathy, induced by monosegmental prolapsed disc and spondylosis. To assess pre- and postoperative clinical and radiological findings related to myelopathy, and factors influencing the outcome, 20 disc herniation (group A) and 11 spondylosis patients (group B) were studied. Average duration of myelopathy in groups A and B were 3 and 8.7 months, respectively. Anterior decompression and fusion were performed. Pre- and postoperative clinical and radiological findings and outcomes were assessed. Average preoperative disc heights were 85.9% of normal in group A and 72.7% in group B. Average anteroposterior canal diameter and Pavlov ratio at diseased level were 13.9 mm and 0.81 in group A, respectively, and 12.1 mm and 0.78 in group B. Five group A (25.0%) and four group B cases (36.4%) had radiculopathy. Cord compressions among 20 group A patients were median in seven and paramedian in 13. In the 11 group B patients, nine were median and two were paramedian. High signal intensity was observed in 19 group A and ten group B patients. Postoperative regression of T(2)-weighted high signal intensity in 14 group A (73.7%) and two group B patients (20.0%) was observed. Preoperative JOA scores in groups A and B were 10.3 and 12.8, respectively, which became 66.2 and 22.5 postoperatively. Neurological recovery was poorer in group B than in group A. Outcome was influenced by chronicity of myelopathy.

Significance of serial S100b and NSE serum measurements in surgically treated patients with spondylotic cervical myelopathy

BACKGROUND

Predicting functional outcome following surgery performed for spinal cord compression is still a considerable problem. Recent observations, though, strongly suggest that with serial measurements of serum S100b, this might be possible in patients with subacute spinal cord compression. The aim of this study was to examine whether this potential significance of S100b applies as well to patients with spondylotic cervical myelopathy. A further purpose was to assess the value of NSE in this regard, another biochemical marker widely used to monitor cerebral lesions.

METHODS

Fifty-one patients were included in this prospective study. Outcome was considered as favourable in case of neurological improvement with preservation or retrieval of walking ability, whereas non-improvement without restoration of gait function was regarded as unfavourable. The preoperative levels of S100b and NSE were correlated with the degree of paresis, duration of symptoms, and presence of intramedullary high signal intensities on MRI. The postoperative values of both markers were correlated with outcome.

FINDINGS

The preoperative levels of S100b were neither correlated with degree or duration of paresis nor with outcome. In case of an uncomplicated course the postoperative levels of S100b were also not correlated with outcome. In complicated courses with acute postoperative deterioration normal values on the 3rd day after the event were associated with a favourable outcome, whereas one patient with unfavourable outcome showed a persistent pathological increase. The serum levels of NSE were not correlated with clinical parameters or with outcome in any of the cases.

CONCLUSIONS

Serial S100b serum measurements do not permit prediction of functional outcome in patients with spondylotic cervical myelopathy in case of an uncomplicated postoperative course. In complicated courses with postoperative deterioration, such measurements reflect postoperative events with possibly prognostic relevance. NSE does not have any significance in these patients with chronic lesions of the spinal cord.

Neurological recovery after surgical decompression in patients with cervical spondylotic myelopathy - a prospective study

Cervical spondylotic myelopathy is a common clinical problem. No study has examined the pattern of neurological recovery after surgical decompression. We conducted a prospective study on the pattern of neurological recovery after surgical decompression in patients with cervical spondylotic myelopathy. Patients suffering from cervical spondylotic myelopathy and requiring surgical decompression from January 1995 to December 2000 were prospectively included. Upper limbs, lower limbs and sphincter functions were assessed using the Japanese Orthopaedic Association (JOA) score. Assessment was done before the operation, at 1 week, 2 weeks, 1 month, 3 months, 6 months, 1 year and then yearly after surgery. Results were analysed with the t-test. Differences with P-values less than 0.05 were regarded as statistically significant. Fifty-five patients were included. The average follow-up period was 53 months. Thirty-nine patients (71%) had neurological improvement after the operation with a mean recovery rate of 55%. The JOA score improved after surgery, reaching statistical significance at 3 months and a plateau at 6 months. Thirty-six patients (65%) had improvement of upper limb function. Twenty-four patients (44%) had improvement of lower limb function. Eleven patients (20%) had improvement of sphincter function. The recovery rate of upper limb function was 37%, of lower limb function was 23% and of sphincter function was 17%. Surgical decompression worked well in patients with cervical spondylotic myelopathy. Seventy-one percent of patients had neurological improvement after the operation. The neurological recovery reached a plateau at 6 months after the operation. The upper limb function had the best recovery, followed by lower limb and sphincter functions.

Clinical and radiological results of hydroxyapatite-coated acetabular cups

We prospectively studied a consecutive series of 60 primary total hip arthroplasties in 52 patients. All patients had a hydroxyapatite-coated hemispherical acetabular cup (OCTOFIT). Mean patient age was 52.5 (34-73) years. In 38 hips, a 28-mm and in 22 hips a 32-mm diameter cobalt-chrome femoral head was used. We could follow 53 hips for a mean of 81 (28-125) months. Four cups were revised because of osteolysis, and in another six cups, slight osteolysis without migration was seen. The average annual linear wear rate was 0.05 mm (+/-0.05) for 28-mm heads and 0.16 mm (+/-0.09) for 32-mm heads (p<0.0001). Survivorship analysis predicted a survival rate of 86+/-6.7% at 10 years.