Change in morphology of intramedullary T2-weighted increased signal intensity after anterior decompressive surgery for cervical spondylotic myelopathy

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN

A retrospective chart review at a single institution.

PATIENT SAMPLE

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Increased signal intensity on postoperative T2-weighted axial images in cervical spondylotic myelopathy: Patterns of changes and associated impact on outcomes

Although T2-weighted axial magnetic resonance imaging (MRI) has strength in demonstrating morphologic characteristics of the spinal cord in cervical spondylotic myelopathy (CSM), no study has investigated postoperative changes. We aimed to assess postoperative changes on T2-weighted axial MRI using the classification system based on axial imaging in cervical compressive myelopathy (Ax-CCM) and associated impact on outcome in CSM. In total, 250 patients with CSM who underwent decompressive surgery with preoperative and postoperative MRI were included. At first, we investigated the presence of increased signal intensity (SI) in cervical spinal cord on T2-weighted sagittal images. Next, the increased SI was assessed using Ax-CCM on T2weighted axial images. The classifications were type 0, no-signal abnormality; single-level type 1, diffuse; single-level type 2, fuzzy focal; single-level type 3, discrete focal; and two-level. The recovery rates (RRs) of modified Japanese Orthopaedic Association (mJOA) score were evaluated from 5 to 10 months postoperatively. Eighty-seven patients (34.8%) exhibited postoperative changes. Most of postoperative changes were in single-level type 1 and 2. Patterns of changes were resolution, reduced extent, or transition to discrete margin. The most common pattern was resolution in type 1 (23.9%) and transition to discrete margin in type 2 (46.5%). In each group, resolution showed the best RR, but insignificantly (p > 0.05).

Updated Return-to-Play Recommendations for Collision Athletes After Cervical Spine Injury: A Modified Delphi Consensus Study With the Cervical Spine Research Society

BACKGROUND

Previous studies have attempted to establish return-to-play (RTP) guidelines in collision sport athletes after cervical spine injury; however, recommendations have been limited by scant high-quality evidence and basic consensus survey methodologies.

OBJECTIVE

To create relevant clinical statements regarding management in collision sport athletes after cervical spine injury, and establish consensus RTP recommendations.

METHODS

Following the modified Delphi methodology, a 3 round survey study was conducted with spine surgeons from the Cervical Spine Research Society and National Football League team physicians in order to establish consensus guidelines and develop recommendations for cervical spine injury management in collision sport athletes.

RESULTS

Our study showed strong consensus that asymptomatic athletes without increased magnetic resonance imaging (MRI) T2-signal changes following 1-/2- level anterior cervical discectomy and fusion (ACDF) may RTP, but not after 3-level ACDF (84.4%). Although allowed RTP after 1-/2-level ACDF was noted in various scenarios, the decision was contentious. No consensus RTP for collision athletes after 2-level ACDF was noted. Strong consensus was achieved for RTP in asymptomatic athletes without increased signal changes and spinal canal diameter &gt;10 mm (90.5%), as well as those with resolved MRI signal changes and diameter &gt;13 mm (81.3%). No consensus was achieved in RTP for cases with pseudarthrosis following ACDF. Strong consensus supported a screening MRI before sport participation in athletes with a history of cervical spine injury (78.9%).

CONCLUSION

This study provides modified Delphi process consensus statements regarding cervical spine injury management in collision sport athletes from leading experts in spine surgery, sports injuries, and cervical trauma. Future research should aim to elucidate optimal timelines for RTP, as well as focus on prevention of injuries.

Postoperative Resolution of MR T2 Increased Signal Intensity in Cervical Spondylotic Myelopathy: The Impact of Signal Change Resolution on the Outcomes

STUDY DESIGN

A prospective comparative imaging study.

OBJECTIVE

This study investigated whether postoperative resolution of spinal cord increased signal intensity (ISI) reflected symptom improvement and surgical outcomes in cervical spondylotic myelopathy (CSM) patients.

SUMMARY OF BACKGROUND DATA

Although some CSM patients exhibit magnetic resonance imaging (MRI) ISI, its alteration and resolution have not been investigated. The association between postoperative ISI resolution and surgical outcomes in CSM patients remains controversial.

METHODS

A total of 505 consecutive CSM patients (311 males; 194 females) aged a mean of 66.6 years (range, 41-91) were enrolled. All were treated with laminoplasty and underwent MRI scans preoperatively and after an average of 26.5 months postoperatively (range 12-66 months). ISI was classified pre- and postoperatively based on sagittal T2-weighted magnetic resonance images into Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients' pre- and postoperative neurological statuses were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy [Japanese Orthopedic Association (JOA) score] and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test.

RESULTS

A total of 337 patients showed preoperative ISI. Among these, 42 (12.5%) showed postoperative ISI resolution, associated with better postoperative JOA score and recovery rate, 10-s G&R and 10-s step test scores than those who retained it. Patients with preoperative Grade 2 ISI had no postoperative ISI resolution. Patients with ISI improvement from Grade 1 to Grade 0 had better outcomes than those with ISI worsening from Grade 1 to Grade 2.

CONCLUSION

Postoperative ISI resolution in CSM patients reflects postoperative symptoms and surgical outcomes. Patients who exhibit ISI resolution have better clinical outcomes.

LEVEL OF EVIDENCE

3.

Comparison between quantitative measurements of diffusion tensor imaging and T2 signal intensity in a large series of cervical spondylotic myelopathy patients for assessment of disease severity and prognostication of recovery

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is a common cause of spinal cord dysfunction. Recently, it has been shown that diffusion tensor imaging (DTI) may be a better biomarker than T2-weighted signal intensity (T2SI) on MRI for CSM. However, there is very little literature on a comparison between the quantitative measurements of DTI and T2SI in the CSM patient population to determine disease severity and recovery.

METHODS

A prospective analysis of 46 patients with both preoperative DTI and T2-weighted MRI was undertaken. Normalized T2SI (NT2SI), regardless of the presence or absence of T2SI at the level of maximum compression (LMC), was determined by calculating the T2SI at the LMC/T2SI at the level of the foramen magnum. Regression analysis was performed to determine the relationship of fractional anisotropy (FA), a quantitative measure derived from DTI, and NT2SI individually as well their combination with baseline preoperative modified Japanese Orthopaedic Association (mJOA) score and ∆mJOA score at the 3-, 6-, 12-, and 24-month follow-ups. Goodness-of-fit analysis was done using residual diagnostics. In addition, mixed-effects regression analysis was used to evaluate the impact of FA and NT2SI individually. A p value < 0.05 was selected to indicate statistical significance.

RESULTS

Regression analysis showed a significant positive correlation between FA at the LMC and preoperative mJOA score (p = 0.041) but a significant negative correlation between FA at the LMC and the ΔmJOA score at the 12-month follow-up (p = 0.010). All other relationships between FA at the LMC and the baseline preoperative mJOA score or ∆mJOA score at the 3-, 6-, and 24-month follow-ups were not statistically significant. For NT2SI and the combination of FA and NT2SI, no significant relationships with preoperative mJOA score or ∆mJOA at 3, 6, and 24 months were seen on regression analysis. However, there was a significant correlation of combined FA and NT2SI with ∆mJOA score at the 12-month follow-up. Mixed-effects regression revealed that FA measured at the LMC was the only significant predictor of ΔmJOA score (p = 0.03), whereas NT2SI and time were not. Goodness-of-fit analysis did not show any evidence of lack of fit.

CONCLUSIONS

In this large prospective study of CSM patients, FA at LMC appears to be a better biomarker for determining long-term outcomes following surgery in CSM patients than NT2SI or the combination values at LMC.

Alterations in Intramedullary T2-weighted Increased Signal Intensity following Laminoplasty in Cervical Spondylotic Myelopathy Patients: Comparison Between Pre- and Postoperative Magnetic Resonance Images

STUDY DESIGN

A prospective comparative imaging study.

OBJECTIVE

This study investigated whether the postoperative classification of and alterations in increased signal intensity (ISI) of the spinal cord reflected the postoperative severity of symptoms and surgical outcomes in cervical spondylotic myelopathy (CSM) patients.

SUMMARY OF BACKGROUND DATA

Although ISI on performing magnetic resonance imaging (MRI) is observed in CSM patients, alterations in ISI have not been investigated. The association of postoperative ISI with surgical outcomes in CSM patients remains controversial.

METHODS

Totally, 505 consecutive CSM patients (311 males) with a mean age of 66.6 (range, 41-91) years were enrolled. All were treated with laminoplasty and underwent MRI scans: preoperatively and after an average of 26.5 months postoperatively (range 12-66 months). ISI was classified pre- and postoperatively into three groups based on sagittal T2-weighted magnetic resonance images: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients' pre- and postoperative neurological statuses were evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test.

RESULTS

Preoperatively, 168 patients had Grade 0 ISI, 169 had Grade 1, and 168 had Grade 2; postoperatively, 210 patients had Grade 0 ISI, 94 had Grade 1, and 201 had Grade 2. Patients with postoperative Grade 0 ISI had a better postoperative JOA score, recovery rate, and 10-s G&R and 10-s step test scores than those with other grades. The postoperative ISI grade improved in 66 patients (13.1%), worsened in 57 (11.3%), and remained unchanged in 382 (75.6%).

CONCLUSION

Postoperative ISI partially reflects postoperative symptoms and surgical outcomes. Alterations in ISI were observed postoperatively in 123 patients (24.4%) and were not correlated with surgical outcomes.

LEVEL OF EVIDENCE

2.

Comparison of the Prognostic Value of Different Quantitative Measurements of Increased Signal Intensity on T2-Weighted MRI in Cervical Spondylotic Myelopathy

OBJECTIVE

To investigate whether different quantitative measurements of increased signal intensity (ISI) on T2-weighted magnetic resonance imaging are useful for predicting surgical outcome in patients with cervical spondylotic myelopathy (CSM).

METHODS

We retrospectively reviewed 108 patients with ISI who underwent surgery for CSM. Clinical outcome was evaluated via the Japanese Orthopaedic Association (JOA) score and the recovery rate. Patients were divided into 2 groups based on the JOA recovery rate: good (≥50%) and fair (<50%). The quantitative measurements of ISI included the maximum vertical length and the signal change ratio (SCR). C2-C7 sagittal alignment, C2-C7 sagittal vertical axis, C2-C7 range of motion, maximum spinal cord compression, and maximum canal compromise also were assessed.

RESULTS

There were no significant differences in cervical sagittal alignment parameters between the groups. Multivariate analysis showed that a longer duration of symptoms, a lower preoperative JOA score, a longer preoperative ISI length, and a greater preoperative SCR were negatively associated with clinical outcomes. Receiver operating characteristic curve analysis showed that the best cutoff values of ISI length and SCR as negative predictors of surgical outcome were 15.50 mm and 1.56, respectively, and the areas under the receiver operating characteristic curve of preoperative ISI length, SCR that discriminate recovery rate of JOA score (≥50%, <50%) were 0.8507, 0.8422, respectively, and was 0.8903 for a combination of the 2.

CONCLUSIONS

Duration of symptoms, preoperative JOA score, preoperative ISI length, and SCR can reflect surgical outcome in patients with CSM; however, cervical sagittal alignment may not affect surgical outcome. Combining ISI length and SCR to depict ISI on T2-weighted magnetic resonance imaging is optimal and accurate. Patients with ISI length >15.50 mm and SCR >1.56 have fair surgical recovery.

Postoperative Resolution of Magnetic Resonance Imaging Signal Intensity Changes and the Associated Impact on Outcomes in Degenerative Cervical Myelopathy: Analysis of a Global Cohort of Patients

STUDY DESIGN

Subanalysis of the prospective AOSpine CSM North America and International studies.

OBJECTIVE

To describe the postoperative changes in magnetic resonance imaging (MRI) spinal cord signal intensity in degenerative cervical myelopathy (DCM) patients and to investigate the impact of its postoperative resolution on clinical outcomes.

SUMMARY OF BACKGROUND DATA

When examining the spinal cord, hyperintensity found in MRI T2-weighted images and hypointensity in T1-weighted images are known to correlate with preoperative severity of DCM and to predict postoperative neurological recovery. However, the clinical importance of these signal intensity changes in postoperative images has not been established.

METHODS

Among 757 surgical DCM patients enrolled in two prospective multicenter studies, postoperative MRI images obtained between 6 and 24 months after the operation were examined with a focus on T2 hyper- and T1 hypointensity in the spinal cord. The 2-year postoperative Nurick grade, modified Japanese Orthopaedic Association score and modified Japanese Orthopaedic Association recovery rate (RR) were analyzed between patients with or without resolution of signal intensity changes.

RESULTS

A total of 167 patients with preoperative T2 hyperintensity were included with complete postoperative MRI images. Of these patients, 11% showed resolution of signal intensity changes, 70% retained T2 hyperintensity only, and 19% showed both T2 hyper- and T1 hypointensity postoperatively. There was a stepwise trend toward worse postoperative outcomes, with the no signal intensity change group showing the best outcome and the T1 hypointensity group showing the worst (mean RR: 72% vs. 51% vs. 36%, P = 0.02). Patients who exhibited resolution of T2 hyperintensity showed better outcomes than those who retained it (RR: 72% vs. 47%, P = 0.04), but the resolution of T1 hypointensity was not associated with improved outcomes (RR: 38% vs. 26%, P = 0.36).

CONCLUSION

Postoperative resolution of T2 hyperintensity in patients with DCM was associated with the best clinical outcomes, whereas those with T1 hypointensity showed the worst.

LEVEL OF EVIDENCE

3.

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 Relationship Between MRI Signal Intensity Changes, Clinical Presentation, and Surgical Outcome in Degenerative Cervical Myelopathy: Analysis of a Global Cohort

STUDY DESIGN

Retrospective analysis of prospective data.

OBJECTIVE

To assess the relationship between MRI signal intensity changes, clinical presentation, and surgical outcome in degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Several studies have sought to assess the extent of spinal cord dysfunction and the potential for postoperative neurological recovery through the evaluation of spinal cord signal change on T2-weighted (T2WI) and T1-weighted images (T1WI). There remains ambiguity if T2WI and T1WI signal changes (1) relate to baseline severity, and (2) predict neurological recovery after surgical treatment.

METHODS

Four hundred nineteen MRIs from two prospective multicenter studies were examined. Images were assessed for the presence, levels, and location of spinal cord signal intensity changes and compared with clinical data. Signal changes were also evaluated for the prediction of 2-year postoperative outcome using mJOA parameters.

RESULTS

MRIs were categorized by T1WI and T2WI signal change: no signal change (28.9%), T2WI hyperintensity-only (T2WI-only, 51.8%), and T2WI-hyperintensity and T1WI-hypointensity (T1WI+T2WI, 19.3%). T2WI-hyperintensity was present at multiple levels in 27% of patients overall. Baseline severity increased from no signal change to T2WI-only to T2WI+T1WI (P < 0.0001), and there was an incremental increase in the frequency of signs/symptoms. There were no differences in outcomes between no signal change and T2WI-only groups. The presence of T1WI-hypointensity correlated with reduced recovery ratio (P = 0.03) and likelihood of an optimal surgical outcome (P = 0.005), adjusting for baseline mJOA. A greater number of T2WI-hyperintensity levels was also associated with worse baseline severity (P < 0.0001) and recovery ratio (P = 0.001).

CONCLUSION

This analysis of a global cohort of DCM patients shows a stepwise trend toward increasing impairment from no signal change to T2WI-hypertensity to T1WI-hypointensity. T1WI signal change indicates more permanent injury, portending decreased functional recovery. T2WI-hyperintensity alone does not predict outcomes. Multiple levels of T2WI-hyperintensity suggest additional tissue injury, correlating with worse clinical impairment and recovery potential.

LEVEL OF EVIDENCE

2.

Surgical outcomes after laminoplasty for cervical spondylotic myelopathy: A focus on the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI

OBJECTIVE

We aimed to analyze the relationship between the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI, and surgical outcomes, following double-door laminoplasty for cervical spondylotic myelopathy (CSM).

PATIENTS AND METHODS

This retrospective study included 100 consecutive patients who underwent double-door laminoplasty for CSM. The following factors were analyzed: JOA score recovery rate, age, duration from onset to surgery, intraoperative bleeding, signal intensity changes in the intramedullary spinal cord on MRI, pre and postoperative C2-7 lordotic angle (LA), changes in C2-7 LA, pre and postoperative C2-7 range of motion (ROM), and pre and postoperative segmental ROM. The Charlson Comorbidity Index (CCI) was also used for the assessment of complications.

RESULTS

Age, CCI, preoperative segmental ROM, and pre and postoperative MRI grade significantly correlated with JOA score recovery rate (P<0.01), whereas number of expanded laminae, duration from onset to surgery, surgery time, intraoperative bleeding, preoperative and postoperative C2-7 LA, change in C2-7 LA, and preoperative C2-7 ROM did not. Multivariate analysis showed that the preoperative segmental ROM (OR=-0.988, P=0.017) and preoperative MRI grade (OR=-7.170, P=0.042) were significantly associated with JOA score recovery rate.

CONCLUSION

Considering the dynamic factors, there was no correlation with C2-7 ROM and surgical outcome, but preoperative segmental ROM and a change in signal intensity of the intramedullary spinal cord on MRI were negatively correlated with surgical outcome. From these results, we suggest that preoperative segmental ROM is possibly associated with spinal cord damage due to repeated minor trauma and affects surgical outcome of laminoplasty.

MRI Analysis of the Combined Prospectively Collected AOSpine North America and International Data: The Prevalence and Spectrum of Pathologies in a Global Cohort of Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

An ambispective analysis.

OBJECTIVE

The aim of this study was to report the global prevalence of specific degenerative cervical pathologies in patients with degenerative cervical myelopathy (DCM) through detailed review of magnetic resonance imaging (MRIs).

SUMMARY OF BACKGROUND DATA

DCM encompasses a spectrum of age-related conditions that result in progressive spinal cord injury.

METHODS

MRIs of 458 patients (age 56.4 ± 11.8, 285 male, 173 female) were reviewed for specific degenerative features, directionality of cord compression, levels of spinal cord compression, and signal changes on sagittal T2-weighted imaging (T2WI) and sagittal T1-weighted imaging (T1WI). Data were analyzed for differences between sex using Chi-square tests and geographic variations using Kruskal-Wallis tests.

RESULTS

Spondylosis was frequently present (89.7%) and was commonly accompanied by enlargement of the ligamentum flavum (LF) (59.9%). Single-level disc pathology, ossification of posterior longitudinal ligament (OPLL), and spondylolisthesis had a prevalence of ∼10% each. OPLL was accompanied by spondylosis in 91.7%. Klippel-Feil syndrome was observed in 2.0%. The Asia-Pacific region had more OPLL (29%, P = 3 × 10) and less spondylolisthesis (1.9%, P = 0.002). Females presented more commonly with single-level disc pathology (13.9% vs. 6.7%; P = 0.013), and males with spondylosis (92.3% vs. 85.6%; P = 0.02) and enlargement of LF (61.4% vs. 49.1%; P = 0.01). C5 to C6 was the most frequent maximum compressed site (39.5%) and region for T2WI hyperintensity (38.9%). T2WI hyperintensity more commonly presented in males (82.4% vs. 66.7%; P < 0.001).

CONCLUSION

This is the largest report on the prevalence and spectrum of pathology in patients with DCM. Herein, it has been demonstrated that degenerative features are highly interrelated, that females presented with milder MRI evidence of DCM, and that variations exist in the prevalence of pathologies between geographical regions.

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.

Significance of T2 Hyperintensity on Magnetic Resonance Imaging After Cervical Cord Injury and Return to Play in Professional Athletes

BACKGROUND:

Cervical cord magnetic resonance imaging (MRI) T2 hyperintensity is used as evidence of cord trauma in the evaluation and management of athletes in contact sports. The long-term pathophysiologic and prognostic value of this finding is poorly understood, especially in return to play (RTP).

OBJECTIVE:

To examine the significance of T2 hyperintensity in the cervical spinal cord of professional athletes.

METHODS:

Retrospective review of MRI T2 hyperintensity findings between 2007 and 2014 in 5 professional athletes. Pertinent examination and demographics, including mechanism of injury, surgical intervention, radiographs, MRI studies, long-term outcomes, and RTP recommendations were collected.

RESULTS:

Four National Football League players and 1 professional wrestler had prior traumatic neurapraxia that at the time of initial consultation had resolved. MRIs showed congenitally small cervical canal (1) and multilevel spondylosis/stenosis/disc herniation (4) along with focal cord T2 hyperintensity (5). The signal abnormalities were at C3/C4 (3), C4 mid-vertebral body (1), and C5/C6 (1). Four athletes had single-level anterior cervical discectomy and fusion, and 1 was nonoperative. Serial MRI imaging at 3 months after surgery showed hyperintensity partially resolved (4) and unchanged (1), and at 9-months 3 of the 5 completely resolved. Based on the author's RTP criteria, 4 of 5 were released to return to their sport. Clearance for RTP preceded complete resolution of MRI T2 hyperintensity in 3 of 4 athletes. The 2 athletes that have returned to profession sport have not had any additional episodes of neurapraxia or any cervical spine-related complications.

CONCLUSION:

MRI T2 hyperintensity in contact sport athletes who are symptom-free with normal examination and no evidence of spinal instability may not be a contraindication to RTP. Additional observations are needed to confirm this observation.