RE-CODE DCM (REsearch Objectives and Common Data Elements for Degenerative Cervical Myelopathy): A Consensus Process to Improve Research Efficiency in DCM, Through Establishment of a Standardized Dataset for Clinical Research and the Definition of the Research Priorities

STUDY DESIGN

Mixed-method consensus process.

OBJECTIVES

Degenerative cervical myelopathy (DCM) is a common and disabling condition that arises when mechanical stress damages the spinal cord as a result of degenerative changes in the surrounding spinal structures. RECODE-DCM (REsearch Objectives and Common Data Elements for Degenerative Cervical Myelopathy) aims to improve efficient use of health care resources within the field of DCM by using a multi-stakeholder partnership to define the DCM research priorities, to develop a minimum dataset for DCM clinical studies, and confirm a definition of DCM.

METHODS

This requires a multi-stakeholder partnership and multiple parallel consensus development processes. It will be conducted via 4 phases, adhering to the guidance set out by the COMET (Core Outcomes in Effectiveness Trials) and JLA (James Lind Alliance) initiatives. Phase 1 will consist of preliminary work to inform online Delphi processes (Phase 2) and a consensus meeting (Phase 3). Following the findings of the consensus meeting, a synthesis of relevant measurement instruments will be compiled and assessed as per the COSMIN (Consensus-based Standards for the Selection of Health Measurement Instruments) criteria, to allow recommendations to be made on how to measure agreed data points. Phase 4 will monitor and promote the use of eventual recommendations.

CONCLUSIONS

RECODE-DCM sets out to establish for the first time an index term, minimum dataset, and research priorities together. Our aim is to reduce waste of health care resources in the future by using patient priorities to inform the scope of future DCM research activities. The consistent use of a standard dataset in DCM clinical studies, audit, and clinical surveillance will facilitate pooled analysis of future data and, ultimately, a deeper understanding of DCM.

Development and Implementation of Clinical Practice Guidelines: An Update and Synthesis of the Literature With a Focus in Application to Spinal Conditions

STUDY DESIGN

Review.

OBJECTIVES

The objectives of this review are to (a) summarize the role of clinical practice guidelines (CPGs), (b) outline the methodology involved in formulating CPGs, (c) provide an illustration of these principles using a CPG developed for degenerative cervical myelopathy, and (d) highlight the importance of knowledge translation.

METHODS

A review of the literature was conducted to summarize current standards in CPG development and implementation.

RESULTS

CPGs are systematically developed statements intended to affect decisions made by health care providers, policy makers, and patients. The main objectives of CPGs are to synthesize and translate evidence into recommendations, optimize patient outcomes, standardize care, and facilitate shared decision making among physicians, patients, and their caregivers. The main steps involved in the development of CPGs include defining the clinical problem, assembling a multidisciplinary guideline development group and systematic review team, conducting a systematic review of the literature, translating the evidence to recommendations, critically appraising the CPG and updating the document when new studies arise. The final step in developing a CPG is to implement it into clinical practice; this step requires an assessment of the barriers to implementation and the formulation of effective dissemination strategies.

CONCLUSION

CPGs are an important component in the teaching and practice of medicine and are available for a wide spectrum of diseases. CPGs, however, can only be used to influence clinical practice if the recommendations are informed by a systematic review of the literature and developed using rigorous methodology. The opportunity to transform clinical management of spinal conditions is an attractive outcome of the application of high-quality CPGs.

A Systematic Review of Classification Systems for Cervical Ossification of the Posterior Longitudinal Ligament

DESIGN

Systematic review.

OBJECTIVE

To conduct a systematic review to (1) summarize various classification systems used to describe cervical ossification of the posterior longitudinal ligament (OPLL) and (2) evaluate the diagnostic accuracy of various imaging modalities and the reliability of these classification systems.

METHODS

A search was performed to identify studies that used a classification system to categorize patients with OPLL. Furthermore, studies were included if they reported the diagnostic accuracy of various imaging modalities or the reliability of a classification system.

RESULTS

A total of 167 studies were deemed relevant. Five classification systems were developed based on X-ray: the 9-classification system (0.60%); continuous, segmental, mixed, localized or focal, circumscribed and others (92.81%); hook, staple, bridge, and total types (2.40%); distribution of OPLL (2.40%); and K-line classification (4.19%). Six methods were based on computed tomography scans: free-type, contiguous-type, and broken sign (0.60%); hill-, plateau-, square-, mushroom-, irregular-, or round-shaped (5.99%); rectangular, oval, triangular, or pedunculate (1.20%); centralized or laterally deviated (1.80%); plank-, spindle-, or rod-shaped (0.60%); and rule of nine (0.60%). Classification systems based on 3-dimensional computed tomography were bridging and nonbridging (1.20%) and flat, irregular, and localized (0.60%). A single classification system was based on magnetic resonance imaging: triangular, teardrop, or boomerang. Finally, a variation of methods was used to classify OPLL associated with the dura mater (4.19%).

CONCLUSIONS

The most common method of classification was that proposed by the Japanese Ministry of Health, Labour and Welfare. Other important methods include K-line (+/-), signs of dural ossification, and patterns of distribution.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Monitoring for myelopathic progression with multiparametric quantitative MRI

Background

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

Methods

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

Results

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

Conclusions

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

Can microstructural MRI detect subclinical tissue injury in subjects with asymptomatic cervical spinal cord compression? A prospective cohort study

OBJECTIVES

Degenerative cervical myelopathy (DCM) involves extrinsic spinal cord compression causing tissue injury and neurological dysfunction. Asymptomatic spinal cord compression (ASCC) is more common, but its significance is poorly defined. This study investigates if: (1) ASCC can be automatically diagnosed using spinal cord shape analysis; (2) multiparametric quantitative MRI can detect similar spinal cord tissue injury as previously observed in DCM.

DESIGN

Prospective observational longitudinal cohort study.

SETTING

Single centre, tertiary care and research institution.

PARTICIPANTS

40 neurologically intact subjects (19 female, 21 male) divided into groups with and without ASCC.

INTERVENTIONS

None.

OUTCOME MEASURES

Clinical assessments: modified Japanese Orthopaedic Association score and physical examination. 3T MRI assessments: automated morphometric analysis compared with consensus ratings of spinal cord compression, and measures of tissue injury: cross-sectional area, diffusion fractional anisotropy, magnetisation transfer ratio and T2*-weighted imaging white to grey matter signal intensity ratio (T2*WI WM/GM) extracted from rostral (C1-3), caudal (C6-7) and maximally compressed levels.

RESULTS

ASCC was present in 20/40 subjects. Diagnosis with automated shape analysis showed area under the curve >97%. Five MRI metrics showed differences suggestive of tissue injury in ASCC compared with uncompressed subjects (p<0.05), while a composite of all 10 measures (average of z scores) showed highly significant differences (p=0.002). At follow-up (median 21 months), two ASCC subjects developed DCM.

CONCLUSIONS

ASCC appears to be common and can be accurately and objectively diagnosed with automated morphometric analysis. Quantitative MRI appears to detect subclinical tissue injury in ASCC prior to the onset of neurological symptoms and signs. These findings require further validation, but offer the intriguing possibility of presymptomatic diagnosis and treatment of DCM and other spinal pathologies.

Bending the Cost Curve-Establishing Value in Spine Surgery

BACKGROUND

As publically promoted by all stakeholders in health care reform, prospective outcomes registry platforms lie at the center of all current evidence-driven value-based models.

OBJECTIVE

To demonstrate the variability in outcomes and cost at population level and individual patient level for patients undergoing spine surgery for degenerative diseases.

METHODS

Retrospective analysis of prospective longitudinal spine registry data was conducted. Baseline and postoperative 1-year patient-reported outcomes were recorded. Previously published minimal clinically important difference for Oswestry Disability Index (14.9) was used. Back-related resource utilization and quality-adjusted life years (QALYs) were assessed. Variations in outcomes and cost were analyzed at population level and at the individual patient level.

RESULTS

A total of 1454 patients were analyzed. There was significant improvement in patient-reported outcomes at postoperative 1 year ( P < .0001). For patients demonstrating health benefit at population level, 12.5%, n = 182 of patients experienced no gain from surgery and 38%, n = 554 failed to achieve minimal clinically important difference. Mean 1-year QALY-gained was 0.29; 18% of patients failed to report gain in QALY. For patients with 2-year follow-up, surgery resulted in 0.62 QALY-gained at average direct cost of $28 953. A wide variation in both QALY-gained and cost was observed.

CONCLUSION

Spine treatments that on average are cost-effective may have wide variability in value at the individual patient level. The variability demonstrated here represents an opportunity, through registries, to identify specific care that may be less effective, and refine patient-specific care delivery and indications to drive overall group-level treatment value. Understanding value of spine care at an individualized as well as population level will allow clinicians, and eventually payers, to better target resources for improving care for nonresponders, ultimately driving up the average health for the whole population.

Traumatic Spinal Cord Injury-Repair and Regeneration

BACKGROUND

Traumatic spinal cord injuries (SCI) have devastating consequences for the physical, financial, and psychosocial well-being of patients and their caregivers. Expediently delivering interventions during the early postinjury period can have a tremendous impact on long-term functional recovery.

PATHOPHYSIOLOGY

This is largely due to the unique pathophysiology of SCI where the initial traumatic insult (primary injury) is followed by a progressive secondary injury cascade characterized by ischemia, proapoptotic signaling, and peripheral inflammatory cell infiltration. Over the subsequent hours, release of proinflammatory cytokines and cytotoxic debris (DNA, ATP, reactive oxygen species) cyclically adds to the harsh postinjury microenvironment. As the lesions mature into the chronic phase, regeneration is severely impeded by the development of an astroglial-fibrous scar surrounding coalesced cystic cavities. Addressing these challenges forms the basis of current and upcoming treatments for SCI.

MANAGEMENT

This paper discusses the evidence-based management of a patient with SCI while emphasizing the importance of early definitive care. Key neuroprotective therapies are summarized including surgical decompression, methylprednisolone, and blood pressure augmentation. We then review exciting neuroprotective interventions on the cusp of translation such as Riluzole, Minocycline, magnesium, therapeutic hypothermia, and CSF drainage. We also explore the most promising neuroregenerative strategies in trial today including Cethrin™, anti-NOGO antibody, cell-based approaches, and bioengineered biomaterials. Each section provides a working knowledge of the key preclinical and patient trials relevant to clinicians while highlighting the pathophysiologic rationale for the therapies.

CONCLUSION

We conclude with our perspectives on the future of treatment and research in this rapidly evolving field.

Risk Factors for and Clinical Outcomes of Dysphagia After Anterior Cervical Surgery for Degenerative Cervical Myelopathy: Results from the AOSpine International and North America Studies

BACKGROUND

Although dysphagia is a common complication after anterior cervical decompression and fusion, important risk factors have not been rigorously evaluated. Furthermore, the impact of dysphagia on neurological and quality-of-life outcomes is not fully understood. The aim of this study was to determine the prevalence of and risk factors for dysphagia, and the impact of this complication on short and long-term clinical outcomes, in patients treated with anterior cervical decompression and fusion.

METHODS

Four hundred and seventy patients undergoing a 1-stage anterior or 2-stage anteroposterior cervical decompression and fusion were enrolled in the prospective AOSpine CSM (Cervical Spondylotic Myelopathy) North America or International study at 26 global sites. Logistic regression analyses were conducted to determine important clinical and surgical predictors of perioperative dysphagia. Preoperatively and at each follow-up visit, patients were evaluated using the modified Japanese Orthopaedic Association scale (mJOA), Nurick score, Neck Disability Index (NDI), and Short Form-36 Health Survey (SF-36). A 2-way repeated-measures analysis of covariance was used to evaluate differences in outcomes at 6 and 24 months between patients with and those without dysphagia, while controlling for relevant baseline characteristics and surgical factors.

RESULTS

The overall prevalence of dysphagia was 6.2%. Bivariate analysis showed the major risk factors for perioperative dysphagia to be a higher comorbidity score, older age, a cardiovascular or endocrine disorder, a lower SF-36 Physical Component Summary score, 2-stage surgery, and a greater number of decompressed levels. Multivariable analysis showed patients to be at an increased risk of perioperative dysphagia if they had an endocrine disorder, a greater number of decompressed segments, or 2-stage surgery. Both short and long-term improvements in functional, disability, and quality-of-life scores were comparable between patients with and those without dysphagia.

CONCLUSIONS

The most important predictors of dysphagia are an endocrine disorder, a greater number of decompressed levels, and 2-stage surgery. At the time of both short and long-term follow-up, patients with perioperative dysphagia exhibited improvements in functional, disability, and quality-of life scores that were similar to those of patients without dysphagia.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Anterior and Posterior Surgery for Degenerative Cervical Myelopathy: An MRI-Based Propensity-Score-Matched Analysis Using Data from the Prospective Multicenter AOSpine CSM North America and International Studies

BACKGROUND

Surgeons often choose between 2 different approaches (anterior and posterior) for surgical treatment of degenerative cervical myelopathy on the basis of imaging features of spinal cord compression, the number of levels affected, and the spinal alignment. However, there is a lack of consensus on which approach is preferable. The objective of the present study was to use magnetic resonance imaging (MRI)-based propensity-score-matched analysis to compare postoperative outcomes between the anterior and posterior surgical approaches for degenerative cervical myelopathy.

METHODS

A total of 757 patients were enrolled in 2 prospective multicenter AOSpine studies, which involved 26 international sites. Preoperative MRIs were reviewed to characterize the causes of the cord compression, including single-level disc disease, multilevel disc disease, ossification of the posterior longitudinal ligament, enlargement of the ligamentum flavum, vertebral subluxation/spondylolisthesis, congenital fusion, number of compressed levels, or kyphosis. The propensity to choose anterior decompression was calculated using demographic data, preoperative MRI findings, and the modified Japanese Orthopaedic Association (mJOA) scores in a logistic regression model. We then performed 1-to-1 matching of patients who had received anterior decompression with those who had the same propensity score but had received posterior decompression to compare 2-year postoperative outcomes and 30-day perioperative complication rates between the 2 groups after adjustment for background characteristics.

RESULTS

A total of 435 cases were included in the propensity score calculation, and 1-to-1 matching resulted in 80 pairs of anterior and posterior surgical cases; 99% of these matched patients had multilevel compression. The anterior and posterior groups did not differ significantly in terms of the postoperative mJOA score (15.1 versus 15.3, p = 0.53), Neck Disability Index (20.5 versus 24.1, p = 0.44), or Short Form-36 (SF-36) Physical Component Summary (PCS) score (41.9 versus 40.9, p = 0.30). The overall rates of perioperative complications were similar between the 2 groups (16% versus 11%, p = 0.48); however, dysphagia/dysphonia was reported only in the anterior group whereas surgical site infection and C5 radiculopathy were reported only in the posterior group.

CONCLUSIONS

Anterior and posterior decompression for degenerative cervical myelopathy resulted in similar postoperative outcomes and rates of complications.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Need for Clinical Practice Guidelines in Assessing and Managing Perioperative Neurologic Deficit: Results from a Survey of the AOSpine International Community

OBJECTIVES

There is no standardized approach to assess and manage perioperative neurologic deficit (PND) in patients undergoing spinal surgery. This survey aimed to evaluate the awareness and usage of clinical practice guidelines (CPGs) as well as investigate how surgeons performing spine surgeries feel about and manage PND and how they perceive the value of developing CPGs for the management of PND.

METHODS

An invitation to participate was sent to the AOSpine International community. Questions were related to the awareness, usage of CPGs, and demographics. Results from the entire sample and subgroups were analyzed.

RESULTS

Of 770 respondents, 659 (85.6%) reported being aware of the existence of guideline(s), and among those, 578 (87.7%) acknowledged using guideline(s). Overall, 58.8% of surgeons reported not feeling comfortable managing a patient who wakes up quadriplegic after an uneventful multilevel posterior cervical decompression with instrumented fusion. Although 22.9% would consider an immediate return to the operating room, the other 77.1% favored conducting some kind of investigation/medical intervention first, such as performing magnetic resonance imaging (85.9%), administrating high-dose corticosteroids (50.2%), or increasing the mean arterial pressure (44.7%). Overall, 90.6% of surgeons believed that CPGs for the management of PND would be useful and 94.4% would be either likely or extremely likely to use these CPGs in their clinical practice.

CONCLUSIONS

Most respondents are aware and routinely use CPGs in their practice. Most surgeons performing spine surgeries reported not feeling comfortable managing PND. However, they highly value the creation and are likely to use CPGs in its management.

Delayed decompression exacerbates ischemia-reperfusion injury in cervical compressive myelopathy

Degenerative cervical myelopathy (DCM) is the most common progressive nontraumatic spinal cord injury. The most common recommended treatment is surgical decompression, although the optimal timing of intervention is an area of ongoing debate. The primary objective of this study was to assess whether a delay in decompression could influence the extent of ischemia-reperfusion injury and alter the trajectory of outcome in DCM. Using a DCM mouse model, we show that decompression acutely led to a 1.5- to 2-fold increase in levels of inflammatory cytokines within the spinal cord. Delayed decompression was associated with exacerbated reperfusion injury, astrogliosis, and poorer neurological recovery. Additionally, delayed decompression was associated with prolonged elevation of inflammatory cytokines and an exacerbated peripheral monocytic inflammatory response (P < 0.01 and 0.001). In contrast, early decompression led to resolution of reperfusion-mediated inflammation, neurological improvement, and reduced hyperalgesia. Similar findings were observed in subjects from the CSM AOSpine North America and International studies, where delayed decompressive surgery resulted in poorer neurological improvement compared with patients with an earlier intervention. Our data demonstrate that delayed surgical decompression for DCM exacerbates reperfusion injury and is associated with ongoing enhanced levels of cytokine expression, microglia activation, and astrogliosis, and paralleled with poorer neurological recovery.

Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability

BACKGROUND AND PURPOSE

DTI, magnetization transfer, T2*-weighted imaging, and cross-sectional area can quantify aspects of spinal cord microstructure. However, clinical adoption remains elusive due to complex acquisitions, cumbersome analysis, limited reliability, and wide ranges of normal values. We propose a simple multiparametric protocol with automated analysis and report normative data, analysis of confounding variables, and reliability.

MATERIALS AND METHODS

Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences. Cross-sectional area, fractional anisotropy, magnetization transfer ratio, and T2*WI WM/GM signal intensity ratio were calculated. Relationships between MR imaging metrics and age, sex, height, weight, cervical cord length, and rostrocaudal level were analyzed. Test-retest coefficient of variation measured reliability in 24 DTI, 17 magnetization transfer, and 16 T2*WI datasets. DTI with and without cardiac triggering was compared in 10 subjects.

RESULTS

T2*WI WM/GM showed lower intersubject coefficient of variation (3.5%) compared with magnetization transfer ratio (5.8%), fractional anisotropy (6.0%), and cross-sectional area (12.2%). Linear correction of cross-sectional area with cervical cord length, fractional anisotropy with age, and magnetization transfer ratio with age and height led to decreased coefficients of variation (4.8%, 5.4%, and 10.2%, respectively). Acceptable reliability was achieved for all metrics/levels (test-retest coefficient of variation < 5%), with T2*WI WM/GM comparing favorably with fractional anisotropy and magnetization transfer ratio. DTI with and without cardiac triggering showed no significant differences for fractional anisotropy and test-retest coefficient of variation.

CONCLUSIONS

Reliable multiparametric assessment of spinal cord microstructure is possible by using clinically suitable methods. These results establish normalization procedures and pave the way for clinical studies, with the potential for improving diagnostics, objectively monitoring disease progression, and predicting outcomes in spinal pathologies.

Medication Antiparkinsonienne et Bilan Extra-Pyramidal: Etude du Trihexyphenidyl

This study, made on 60 chronic mental patients, had aimed to determine the effective dosage of trihexyphenidyl, an antiparkinsonian drug. During the preliminary period all patients were given a standard medication consisting of a neuroleptic, trifluoperazine 60 mg. daily, and an antiparkinsonian agent, trihexyphenidyl 10 mg. daily. A placebo was substituted for the antiparkinsonian during the first experimental period to measure the patients' extrapyramidal sensitivity. This evaluation was performed with a rating scale (B.E.P.) and observations from the nursing staff.

Patients were divided into three groups of 20 according to their B.E.P. score and received one of the three therapeutic regimens: trihexyphenidyl 15 mg. or 6 mg. or placebo.

Analyses of the results allow us to conclude that for this population a daily dosage of 6 mg. of trihexyphenidyl gives as much protection as 15 mg.; patients receiving an antiparkinsonian agent needed less “p.r.n.” administration of prociclydine. We have also found that if the antiparkinsonian drug can control some extrapyramidal symptoms it might be responsible for the presence of other more complex neurological symptoms.

A Novel MRI Biomarker of Spinal Cord White Matter Injury: T2*-Weighted White Matter to Gray Matter Signal Intensity Ratio

BACKGROUND AND PURPOSE

T2*-weighted imaging provides sharp contrast between spinal cord GM and WM, allowing their segmentation and cross-sectional area measurement. Injured WM demonstrates T2*WI hyperintensity but requires normalization for quantitative use. We introduce T2*WI WM/GM signal-intensity ratio and compare it against cross-sectional area, the DTI metric fractional anisotropy, and magnetization transfer ratio in degenerative cervical myelopathy.

MATERIALS AND METHODS

Fifty-eight patients with degenerative cervical myelopathy and 40 healthy subjects underwent 3T MR imaging, covering C1-C7. Metrics were automatically extracted at maximally compressed and uncompressed rostral/caudal levels. Normalized metrics were compared with t tests, area under the curve, and logistic regression. Relationships with clinical measures were analyzed by using Pearson correlation and multiple linear regression.

RESULTS

The maximally compressed level cross-sectional area demonstrated superior differences (P = 1 × 10^-13), diagnostic accuracy (area under the curve = 0.890), and univariate correlation with the modified Japanese Orthopedic Association score (0.66). T2*WI WM/GM showed strong differences (rostral: P = 8 × 10^-7; maximally compressed level: P = 1 × 10^-11; caudal: P = 1 × 10^-4), correlations (modified Japanese Orthopedic Association score; rostral: -0.52; maximally compressed level: -0.59; caudal: -0.36), and diagnostic accuracy (rostral: 0.775; maximally compressed level: 0.860; caudal: 0.721), outperforming fractional anisotropy and magnetization transfer ratio in most comparisons and cross-sectional area at rostral/caudal levels. Rostral T2*WI WM/GM showed the strongest correlations with focal motor (-0.45) and sensory (-0.49) deficits and was the strongest independent predictor of the modified Japanese Orthopedic Association score (P = .01) and diagnosis (P = .02) in multivariate models (R² = 0.59, P = 8 × 10^-13; area under the curve = 0.954, respectively).

CONCLUSIONS

T2*WI WM/GM shows promise as a novel biomarker of WM injury. It detects damage in compressed and uncompressed regions and contributes substantially to multivariate models for diagnosis and correlation with impairment. Our multiparametric approach overcomes limitations of individual measures, having the potential to improve diagnostics, monitor progression, and predict outcomes.

Prevalence and Outcomes in Patients Undergoing Reintubation After Anterior Cervical Spine Surgery: Results From the AOSpine North America Multicenter Study on 8887 Patients

STUDY DESIGN

A multicenter, retrospective cohort study.

OBJECTIVE

To evaluate clinical outcomes in patients with reintubation after anterior cervical spine surgery.

METHODS

A total of 8887 patients undergoing anterior cervical spine surgery were enrolled in the AOSpine North America Rare Complications of Cervical Spine Surgery study. Patients with or without complications after surgery were included. Demographic and surgical information were collected for patients with reintubation. Patients were evaluated using a variety of assessment tools, including the modified Japanese Orthopedic Association scale, Nurick score, Neck Disability Index, and Short Form-36 Health Survey.

RESULTS

Nine cases of postoperative reintubation were identified. The total prevalence of this complication was 0.10% and ranged from 0% to 0.59% across participating institutions. The time to development of airway symptoms after surgery was within 24 hours in 6 patients and between 5 and 7 days in 3 patients. Although 8 patients recovered, 1 patient died. At final follow-up, patients with reintubation did not exhibit significant and meaningful improvements in pain, functional status, or quality of life.

CONCLUSIONS

Although the prevalence of reintubation was very low, this complication was associated with adverse clinical outcomes. Clinicians should identify their high-risk patients and carefully observe them for up to 2 weeks after surgery.

The reporting of study and population characteristics in degenerative cervical myelopathy: A systematic review

OBJECT

Degenerative cervical myelopathy [DCM] is a disabling and increasingly prevalent condition. Variable reporting in interventional trials of study design and sample characteristics limits the interpretation of pooled outcomes. This is pertinent in DCM where baseline characteristics are known to influence outcome. The present study aims to assess the reporting of the study design and baseline characteristics in DCM as the premise for the development of a standardised reporting set.

METHODS

A systematic review of MEDLINE and EMBASE databases, registered with PROSPERO (CRD42015025497) was conducted in accordance with PRISMA guidelines. Full text articles in English, with >50 patients (prospective) or >200 patients (retrospective), reporting outcomes of DCM were deemed to be eligible.

RESULTS

A total of 108 studies involving 23,876 patients, conducted world-wide, were identified. 33 (31%) specified a clear primary objective. Study populations often included radiculopathy (51, 47%) but excluded patients who had undergone previous surgery (42, 39%). Diagnositic criteria for myelopathy were often uncertain; MRI assessment was specified in only 67 (62%) of studies. Patient comorbidities were referenced by 37 (34%) studies. Symptom duration was reported by 46 (43%) studies. Multivariate analysis was used to control for baseline characteristics in 33 (31%) of studies.

CONCLUSIONS

The reporting of study design and sample characteristics is variable. The development of a consensus minimum dataset for (CODE-DCM) will facilitate future research synthesis in the future.

Clinical and pathological outcomes after resection of intramedullary spinal cord tumors: a single-institution case series

OBJECTIVE The objective of this study was to identify clinically relevant predictors of progression-free survival and functional outcomes in patients who underwent surgery for intramedullary spinal cord tumors (ISCTs). METHODS An institutional spinal tumor registry and billing records were reviewed to identify adult patients who underwent resection of ISCTs between 1993 and 2014. Extensive data were collected from patient charts and operative notes, including demographic information, extent of resection, tumor pathology, and functional and oncological outcomes. Survival analysis was used to determine important predictors of progression-free survival. Logistic regression analysis was used to evaluate the association between an "optimal" functional outcome on the Frankel or McCormick scale at 1-year follow-up and various clinical and surgical characteristics. RESULTS The consecutive case series consisted of 63 patients (50.79% female) who underwent resection of ISCTs. The mean age of patients was 41.92 ± 14.36 years (range 17.60-75.40 years). Complete microsurgical resection, defined as no evidence of tumor on initial postoperative imaging, was achieved in 34 cases (54.84%) of the 62 patients for whom this information was available. On univariate analysis, the most significant predictor of progression-free survival was tumor histology (p = 0.0027). Patients with Grade I/II astrocytomas were more likely to have tumor progression than patients with WHO Grade II ependymomas (HR 8.03, 95% CI 2.07-31.11, p = 0.0026) and myxopapillary ependymomas (HR 8.01, 95% CI 1.44-44.34, p = 0.017). Furthermore, patients who underwent radical or subtotal resection were more likely to have tumor progression than those who underwent complete resection (HR 3.46, 95% CI 1.23-9.73, p = 0.018). Multivariate analysis revealed that tumor pathology was the only significant predictor of tumor progression. On univariate analysis, the most significant predictors of an "optimal" outcome on the Frankel scale were age (OR 0.94, 95% CI 0.89-0.98, p = 0.0062), preoperative Frankel grade (OR 4.84, 95% CI 1.33-17.63, p = 0.017), McCormick score (OR 0.22, 95% CI 0.084-0.57, p = 0.0018), and region of spinal cord (cervical vs conus: OR 0.067, 95% CI 0.012-0.38, p = 0.0023; and thoracic vs conus: OR 0.015: 95% CI 0.001-0.20, p = 0.0013). Age, tumor pathology, and region were also important predictors of 1-year McCormick scores. CONCLUSIONS Extent of tumor resection and histopathology are significant predictors of progression-free survival following resection of ISCTs. Important predictors of functional outcomes include tumor histology, region of spinal cord in which the tumor is present, age, and preoperative functional status.

Return to play in athletes with spinal cord concussion: a systematic literature review

STUDY DESIGN

This is a systematic review.

PURPOSE

The study aimed to evaluate whether spinal cord concussion (SCC) patients can safely return to play sports and if there are factors that can predict SCC recurrence or the development of a spinal cord injury (SCI).

BACKGROUND CONTEXT

Although SCC is a reversible neurologic disturbance of spinal cord function, its management and the implications for return to play are controversial.

METHODS

We conducted a systematic search of the literature using the keywords Cervical Spine AND Sports AND Injuries in six databases. We examined return to play in patients (1) without stenosis, (2) with stenosis, and (3) who underwent single-level anterior cervical discectomy and fusion (ACDF). We also investigated predictors for the risk of SCC recurrence or SCI.

RESULTS

We identified 3,655 unique citations, 16 of which met our inclusion criteria. The included studies were case-control studies or case series and reports. Two studies reported on patients without stenosis: pediatric cases returned without recurrence, whereas an adult case experienced recurrent SCC after returning to play. Seven studies described patients with stenosis. These studies included cases with and without recurrence after return to play, as well as patients who suffered SCI with permanent neurologic deficits. Three studies reported on patients who underwent an ACDF. Although some patients played after surgery without problems, several patients experienced recurrent SCC due to herniation at levels adjacent to the surgical sites. With respect to important predictors, a greater frequency of patients who experienced recurrence of symptoms or SCI following return to play had a "long" duration of symptoms (>24 hours; 36.36%) compared with those who were problem-free (11.11%; p=.0311).

CONCLUSIONS

There is limited evidence on current practice standards for return to play following SCC and important risk factors for SCC recurrence or SCI. Because of small sample sizes, future prospective multicenter studies are needed to determine important predictive factors of poor outcomes following return to play after SCC.