Cervical spondylotic myelopathy: methodological approaches to evaluate the literature and establish best evidence

A Personalized Medicine Approach for the Management of Spinal Metastases with Cord Compression: Development of a Novel Clinical Prediction Model for Postoperative Survival and Quality of Life

Surgery should be considered for patients with metastatic epidural spinal cord compression (MESCC) with a life expectancy of ≥3 months. Given the heterogeneity of the clinical presentation and outcomes, clinical prognostic models (CPMs) can assist in tailoring a personalized medicine approach to optimize surgical decision-making. We aimed to develop and internally validate the first CPM of health-related quality of life (HRQoL) and a novel CPM to predict the survival of patients with MESCC treated surgically. Using data from 258 patients (AOSpine North America MESCC study and Nottingham MESCC registry), we created 1-year survival and HRQoL CPMs using a Cox model and logistic regression analysis with manual backward elimination. The outcome measure for HRQoL was the minimal clinical important difference in EuroQol 5-dimension questionnaire scores. Internal validation involved 200 bootstrap iterations, and calibration and discrimination were evaluated. Longer survival was associated with a higher SF-36 physical component score (hazard ratio [HR], 0.96). In contrast, primary tumor other than breast, thyroid, or prostate (unfavorable: HR, 2.57; other: HR, 1.20), organ metastasis (HR, 1.51), male sex (HR, 1.58), and preoperative radiotherapy (HR, 1.53) were not (c-statistic, 0.69; 95% confidence interval, 0.64-0.73). Karnofsky performance status <70% (odds ratio [OR], 2.50), living in North America (OR, 4.06), SF-36 physical component score (OR, 0.95) and SF-36 mental component score (OR, 0.96) were associated with the likelihood of achieving a minimal clinical important difference improvement in the EuroQol 5-Dimension Questionnaire score at 3 months (c-statistic, 0.74; 95% confidence interval, 0.68-0.79). The calibration for both CPMs was very good. We developed and internally validated the first CPMs of survival and HRQoL at 3 months postoperatively in patients with MESCC using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) guidelines. A web-based calculator is available (available at: http://spine-met.com) to assist with clinical decision-making.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury

STUDY DESIGN

Systematic review.

OBJECTIVE

To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI).

METHODS

An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI.

RESULTS

The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema.

CONCLUSIONS

Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies.

Preoperative Computed Tomography Myelography Parameters as Predictors of Outcome in Patients With Degenerative Cervical Myelopathy: Results of a Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

To determine the preoperative computed tomography (CT) myelogram imaging parameters in patients diagnosed with degenerative cervical myelopathy (DCM) that correlate with severity of DCM and predict postoperative patients' functional outcome.

METHODS

An electronic database search was performed using Ovid Medline and Embase. CT myelogram studies investigating the correlation between imaging characteristics and DCM severity or postoperative outcomes were included. Two independent reviewers performed citation screening, selection, qualitative assessment, and data extraction using an objective and blinded protocol.

RESULTS

A total of 5 studies (402 patients) were included in this review and investigated the role of preoperative CT myelogram parameters in predicting the functional outcome after surgical treatment of DCM. All studies were retrospective cohort studies. CT myelogram characteristics included the transverse area of the spinal cord at maximum level of compression, spinal canal narrowing, number of blocks, spinal canal diameter, and flattening ratio. There is low evidence suggesting that patients with a preoperative transverse area of the spinal cord >30 mm² at the level of maximum compression have better postoperative recovery and outcome. We found no studies investigating the correlation between preoperative CT myelogram parameters and DCM severity.

CONCLUSIONS

Patients with greater transverse area of spinal cord at the level of maximum compression on the preoperative CT myelogram are more likely to have better neurological outcome after surgery. There is insufficient evidence to suggest that any of the other CT myelogram parameters investigated are predictors of postoperative outcomes in patients with DCM.

Timing of Decompression in Patients With Acute Spinal Cord Injury: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To conduct a systematic review and synthesis of the literature to assess the comparative effectiveness, safety, and cost-effectiveness of early (≤24 hours) versus late decompression (>24 hours) in adults with acute spinal cord injury (SCI).

METHODS

A systematic search was conducted of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar to identify studies published through November 6, 2014. Studies published in any language, in humans, and with an abstract were considered for inclusion. Included studies were critically appraised and the overall strength of evidence was determined using methods proposed by the Grading of Recommendation Assessment, Development and Evaluation working group.

RESULTS

The search yielded 449 potentially relevant citations. Sixteen additional primary studies were identified through other sources. Six studies met inclusion criteria. All but 2 studies were considered to have moderately high risk of bias. Across studies and injury levels, the impact of early surgical decompression (≤24 hours) on clinically important improvement in neurological status was variable. Isolated studies reported statistically significant and clinically important improvements at 6 months (cervical injury, low strength of evidence) and following discharge from inpatient rehabilitation (all levels, very low strength of evidence) but not at other time points; another study observed a statistically significant 6 point improvement in ASIA Impairment Scale (AIS) among patients with AIS B, C, or D, but not for those with AIS A (very low strength of evidence). In one study of acute central cord syndrome without instability, a clinically and statistically meaningful improvement in total motor scores was reported at 6 and 12 months in patients treated early (versus late). There were, however, no significant differences in AIS improvement between early and late surgical groups at 6- or 12-months (very low strength of evidence). One of 3 studies found a shorter length of hospital stay associated with early surgical decompression. Of 3 studies reporting on safety, no significant differences in rates of complications (including mortality, neurologic deterioration, pneumonia or pressure ulcers) were noted between early and late decompression groups.

CONCLUSIONS

Results surrounding the efficacy of early versus late decompressive surgery, as well as the quality of evidence available, were variable depending on the level of SCI, timing of follow-up, and specific outcome considered. Existing evidence supports improved neurological recovery among cervical SCI patients undergoing early surgery; however, evidence regarding remaining SCI populations and clinical outcomes was inconsistent.

Guidelines for the Management of Degenerative Cervical Myelopathy and Acute Spinal Cord Injury: Development Process and Methodology

The Institute of Medicine defines clinical practice guidelines as "statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options." Guidelines help clinicians implement best evidence into practice and encourage informed shared decision making with patients. Guidelines are intended to enhance the quality of patient care by discouraging ineffective and potentially harmful interventions and standardizing practice. Standards for the development and appraisal of guidelines, such as those proposed by the Institute of Medicine and other organizations, help assure guideline quality and credibility. Primary standards include establishing transparency, managing conflicts of interest, forming a multidisciplinary guideline development group, conducting methodologically sound systematic reviews, developing evidence-based recommendations, balancing risks and harms, and rating the strength of recommendations based on the confidence in the evidence. Furthermore, the guideline document must be appraised internally and externally and updated when new evidence arises. The Grading of Recommendation, Assessment, Development and Evaluation process helps appraise the existing body of evidence as well as provide an interactive framework for weighing the benefits and harms of treatment options and translating evidence to recommendations. This article summarizes the methodology used to develop clinical practice guidelines for the management of degenerative cervical myelopathy and acute spinal cord injury.

Efficacy, Safety, and Timing of Anticoagulant Thromboprophylaxis for the Prevention of Venous Thromboembolism in Patients With Acute Spinal Cord Injury: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The objective of this study was to answer 5 key questions: What is the comparative effectiveness and safety of (1a) anticoagulant thromboprophylaxis compared to no prophylaxis, placebo, or another anticoagulant strategy for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) after acute spinal cord injury (SCI)? (1b) Mechanical prophylaxis strategies alone or in combination with other strategies for preventing DVT and PE after acute SCI? (1c) Prophylactic inferior vena cava filter insertion alone or in combination with other strategies for preventing DVT and PE after acute SCI? (2) What is the optimal timing to initiate and/or discontinue anticoagulant, mechanical, and/or prophylactic inferior vena cava filter following acute SCI? (3) What is the cost-effectiveness of these treatment options?

METHODS

A systematic literature search was conducted to identify studies published through February 28, 2015. We sought randomized controlled trials evaluating efficacy and safety of antithrombotic strategies. Strength of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Nine studies satisfied inclusion criteria. We found a trend toward lower risk of DVT in patients treated with enoxaparin. There were no significant differences in rates of DVT, PE, bleeding, and mortality between patients treated with different types of low-molecular-weight heparin or between low-molecular-weight heparin and unfractionated heparin. Combined anticoagulant and mechanical prophylaxis initiated within 72 hours of SCI resulted in lower risk of DVT than treatment commenced after 72 hours of injury.

CONCLUSION

Prophylactic treatments can be used to lower the risk of venous thromboembolic events in patients with acute SCI, without significant increase in risk of bleeding and mortality and should be initiated within 72 hours.

Symptomatic spinal metastasis: A systematic literature review of the preoperative prognostic factors for survival, neurological, functional and quality of life in surgically treated patients and methodological recommendations for prognostic studies

Purpose

While several clinical prediction rules (CPRs) of survival exist for patients with symptomatic spinal metastasis (SSM), these have variable prognostic ability and there is no recognized CPR for health related quality of life (HRQoL). We undertook a critical appraisal of the literature to identify key preoperative prognostic factors of clinical outcomes in patients with SSM who were treated surgically. The results of this study could be used to modify existing or develop new CPRs.

Methods

Seven electronic databases were searched (1990–2015), without language restriction, to identify studies that performed multivariate analysis of preoperative predictors of survival, neurological, functional and HRQoL outcomes in surgical patients with SSM. Individual studies were assessed for class of evidence. The strength of the overall body of evidence was evaluated using GRADE for each predictor.

Results

Among 4,818 unique citations, 17 were included; all were in English, rated Class III and focused on survival, revealing a total of 46 predictors. The strength of the overall body of evidence was very low for 39 and low for 7 predictors. Due to considerable heterogeneity in patient samples and prognostic factors investigated as well as several methodological issues, our results had a moderately high risk of bias and were difficult to interpret.

Conclusions

The quality of evidence for predictors of survival was, at best, low. We failed to identify studies that evaluated preoperative prognostic factors for neurological, functional, or HRQoL outcomes in surgical patients with SSM. We formulated methodological recommendations for prognostic studies to promote acquiring high-quality evidence to better estimate predictor effect sizes to improve patient education, surgical decision-making and development of CPRs.

Synthetic bone graft versus autograft or allograft for spinal fusion: a systematic review

The purpose of this review was to compare the efficacy and safety of synthetic bone graft substitutes versus autograft or allograft for the treatment of lumbar and cervical spinal degenerative diseases. Multiple major medical reference databases were searched for studies that evaluated spinal fusion using synthetic bone graft substitutes (either alone or with an autograft or allograft) compared with autograft and allograft. Randomized controlled trials (RCT) and cohort studies with more than 10 patients were included. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. The search yielded 214 citations with 27 studies that met the inclusion criteria. For the patients with lumbar spinal degenerative disease, data from 19 comparative studies were included: 3 RCTs, 12 prospective, and 4 retrospective studies. Hydroxyapatite (HA), HA+collagen, β-tricalcium phosphate (β-TCP), calcium sulfate, or polymethylmethacrylate (PMMA) were used. Overall, there were no differences between the treatment groups in terms of fusion, functional outcomes, or complications, except in 1 study that found higher rates of HA graft absorption. For the patients with cervical degenerative conditions, data from 8 comparative studies were included: 4 RCTs and 4 cohort studies (1 prospective and 3 retrospective studies). Synthetic grafts included HA, β-TCP/HA, PMMA, and biocompatible osteoconductive polymer (BOP). The PMMA and BOP grafts led to lower fusion rates, and PMMA, HA, and BOP had greater risks of graft fragmentation, settling, and instrumentation problems compared with iliac crest bone graft. The overall quality of evidence evaluating the potential use and superiority of the synthetic biological materials for lumbar and cervical fusion in this systematic review was low or insufficient, largely due to the high potential for bias and small sample sizes. Thus, definitive conclusions or recommendations regarding the use of these synthetic materials should be made cautiously and within the context of the limitations of the evidence.

Translating state-of-the-art spinal cord MRI techniques to clinical use: A systematic review of clinical studies utilizing DTI, MT, MWF, MRS, and fMRI

BACKGROUND

A recent meeting of international imaging experts sponsored by the International Spinal Research Trust (ISRT) and the Wings for Life Foundation identified 5 state-of-the-art MRI techniques with potential to transform the field of spinal cord imaging by elucidating elements of the microstructure and function: diffusion tensor imaging (DTI), magnetization transfer (MT), myelin water fraction (MWF), MR spectroscopy (MRS), and functional MRI (fMRI). However, the progress toward clinical translation of these techniques has not been established.

METHODS

A systematic review of the English literature was conducted using MEDLINE, MEDLINE-in-Progress, Embase, and Cochrane databases to identify all human studies that investigated utility, in terms of diagnosis, correlation with disability, and prediction of outcomes, of these promising techniques in pathologies affecting the spinal cord. Data regarding study design, subject characteristics, MRI methods, clinical measures of impairment, and analysis techniques were extracted and tabulated to identify trends and commonalities. The studies were assessed for risk of bias, and the overall quality of evidence was assessed for each specific finding using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

A total of 6597 unique citations were identified in the database search, and after full-text review of 274 articles, a total of 104 relevant studies were identified for final inclusion (97% from the initial database search). Among these, 69 studies utilized DTI and 25 used MT, with both techniques showing an increased number of publications in recent years. The review also identified 1 MWF study, 11 MRS studies, and 8 fMRI studies. Most of the studies were exploratory in nature, lacking a priori hypotheses and showing a high (72%) or moderately high (20%) risk of bias, due to issues with study design, acquisition techniques, and analysis methods. The acquisitions for each technique varied widely across studies, rendering direct comparisons of metrics invalid. The DTI metric fractional anisotropy (FA) had the strongest evidence of utility, with moderate quality evidence for its use as a biomarker showing correlation with disability in several clinical pathologies, and a low level of evidence that it identifies tissue injury (in terms of group differences) compared with healthy controls. However, insufficient evidence exists to determine its utility as a sensitive and specific diagnostic test or as a tool to predict clinical outcomes. Very low quality evidence suggests that other metrics also show group differences compared with controls, including DTI metrics mean diffusivity (MD) and radial diffusivity (RD), the diffusional kurtosis imaging (DKI) metric mean kurtosis (MK), MT metrics MT ratio (MTR) and MT cerebrospinal fluid ratio (MTCSF), and the MRS metric of N-acetylaspartate (NAA) concentration, although these results were somewhat inconsistent.

CONCLUSIONS

State-of-the-art spinal cord MRI techniques are emerging with great potential to improve the diagnosis and management of various spinal pathologies, but the current body of evidence has only showed limited clinical utility to date. Among these imaging tools DTI is the most mature, but further work is necessary to standardize and validate its use before it will be adopted in the clinical realm. Large, well-designed studies with a priori hypotheses, standardized acquisition methods, detailed clinical data collection, and robust automated analysis techniques are needed to fully demonstrate the potential of these rapidly evolving techniques.

Posterior atlantoaxial 'facetal' instability associated with cervical spondylotic disease

Aim:

The association of single or multiple level cervical spondylotic disease with atlantoaxial instability is assessed. The implications of identifying and treating atlantoaxial instability in such an association are highlighted.

Materials and Methods:

The analysis is based on an experience with 11 patients treated during the period June 2013-June 2014. All patients had single or multilevel cervical spondylotic disease. The spinal canal compromise and evidence of cord compression was evident on imaging in the cervical subaxial spine and was related to disc bulges and osteophytic bars. There was no or relatively insignificant compression of the cervicomedullary cord by the odontoid process. There was no evidence of odontoid process-related instability on dynamic imaging. Apart from presence of features of cervical spondylosis, investigations and surgical exploration and direct manual handling of the facets revealed evidence of Type B (posterior) atlantoaxial ‘facetal’ instability in all patients. Our 5-point clinical grading system and Japanese Orthopaedic Association (JOA) scores were used to monitor the patients both before and after surgery and at follow-up. Surgery involved both at lantoaxial and subaxial cervical fixation. During the average period of follow-up of 9 months (5-17 months), all patients showed remarkable and gratifying neurological recovery.

Conclusion:

We conclude that atlantoaxial facetal instability can be ‘frequently’ associated with cervical spondylosis and needs surgical stabilization. Our surgical outcome analysis suggests that missing or ignoring the presence of atlantoaxial facetal instability can be an important cause of suboptimal result or failure of surgery for cervical spondylotic myelopathy.

Comparison of anterior surgical options for the treatment of multilevel cervical spondylotic myelopathy: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

The primary objectives of this review were to compare the effectiveness and safety of various anterior cervical decompressive and reconstructive procedures for diffuse or multifocal cervical spondylotic myelopathy (CSM). An additional objective was to describe the most common ancillary stabilization techniques used with the different anterior decompressive procedures.

SUMMARY OF BACKGROUND DATA

Surgical management of CSM provides for neurological recovery and disease stabilization in a cost-effective way. Although both retrospective and prospective data support management of CSM by anterior cervical decompression and fusion, the choice decision between various anterior surgical options remains unclear.

METHODS

We conducted a systematic search in MEDLINE and the Cochrane Collaboration Library for human studies in the English-language literature published through September 2012. We included studies comparing multiple discectomies with single or multiple corpectomy, multiple discectomies with discectomy-corpectomy hybrid, and multiple corpectomies with discectomy-corpectomy hybrid, comparing effectiveness and safety outcomes of each procedure, and defining the ancillary stabilization techniques used. Exclusion criteria included patients with degenerative disc disease or degenerative joint disease without CSM, single-level CSM, ossified posterior longitudinal ligament (OPLL), spinal tumor, concomitant infection, and ankylozing spondylitis. Case series, case reports, data not reported separately for each comparison group, or studies that consisted of an N less than 10 for either comparison group were excluded. The evidence strength was rated using the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) criteria.

RESULTS

Of the 49 citations identified from our search, 10 studies were initially found suitable for inclusion. Patients undergoing any of the 3 procedures generally experienced improvements in clinical outcomes (neck disability index, Japanese Orthopaedic Association score, and Visual Analogue Scale score for pain) as well as overall sagittal alignment, with minimal perioperative morbidity. There is moderate evidence supporting selection of multiple discectomies compared with corpectomy or discectomy-corpectomy hybrid procedures with regard to superior clinical outcomes and postoperative sagittal alignment. Furthermore, if more extensive operation is needed, there is evidence to support the selection of discectomy-corpectomy hybrid procedures compared with multiple corpectomies if it is technically feasible to accomplish the requisite decompression. The multiple discectomies approach also may have a lower incidence of C5 palsy than corpectomy or discectomy-corpectomy hybrid approaches.

CONCLUSION

All 3 operative approaches are effective strategies for the anterior surgical management of CSM. When the patient pathoanatomy permits, selection of multiple discectomies is favored compared with corpectomy or discectomy-corpectomy hybrid approaches. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION 1

When pathoanatomically appropriate with minimal retrovertebral disease, we recommend the selection of multiple discectomy over corpectomy or discectomy-corpectomy hybrid procedures.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Strong.

RECOMMENDATION 2

When retrovertebral disease is significant, we recommend, when possible, that discectomy-corpectomy hybrid procedures be performed instead of multiple corpectomies.

OVERALL STRENGTH OF EVIDENCE

Moderate.

STRENGTH OF RECOMMENDATION

Strong. SUMMARY STATEMENTS: There is no evidence to guide choice of ancillary external immobilization techniques following multilevel anterior decompression and fusion procedures for CSM.

Systematic review of magnetic resonance imaging characteristics that affect treatment decision making and predict clinical outcome in patients with cervical spondylotic myelopathy

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine whether there are magnetic resonance imaging (MRI) characteristics in patients with cervical spondylotic myelopathy that affect treatment decisions or predict postsurgical outcomes or adverse events.

SUMMARY OF BACKGROUND DATA

Although the role of MRI in confirming the clinical diagnosis of cervical spondylotic myelopathy and directing surgical management is well established, its potential value as a prognostic tool is largely unknown.

METHODS

A systematic search was conducted using PubMed and the Cochrane Collaboration Library for articles published between January 1, 1956, and November 20, 2012. The overall body of evidence with respect to each clinical question was determined on the basis of precepts outlined by the Grading of Recommendation Assessment, Development and Evaluation Working Group and recommendations made by the Agency for Healthcare Research and Quality.

RESULTS

The initial search yielded 268 citations. Twenty publications met all inclusion criteria and were included in the review. Three of these assessed MRI predictors of clinical deterioration in the case of conservative treatment and 17 evaluated MRI anatomic or cord characteristics that could predict surgical outcome or adverse events. There is low evidence suggesting that a high signal intensity (SI) grade on T2WI is not associated with patient deterioration during conservative treatment. High SI grade on T2WI, along with compression ratio and canal diameter, was not an important predictor of outcome. There is low evidence identifying number of high SI segments on T2WI, low SI segments on T1WI, combined T1/T2 SI, and SI ratio as important negative predictors of surgical outcome.

CONCLUSION

On the basis of this review and on low-quality evidence, we have identified 3 important negative predictors of surgical outcome: number of high SI segments on T2WI, combined T1/T2 signal change, and SI ratio.EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION 1

We suggest that when clinically feasible, surgeons rely on MRI to confirm the diagnosis of CSM and rely on clinical history and examination to determine progression and severity of disease.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Weak.

RECOMMENDATION 2

T2 signal may be a useful prognostic indicator when used in combination with low SI change on T1WI, or as a ratio comparing compressed with noncompressed segments, or as a ratio of T2 compared with T1WI. We suggest that if surgeons use MRI signal intensity to estimate the risk of a poor outcome after surgery, they use high SI change on T2WI in combination with other signal intensity parameters, and not in isolation.

OVERALL STRENGTH OF EVIDENCE

Low. StrENGTH OF RECOMMENDATION: Weak.