Change in Impairment following Operative Treatment of Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis

Abstract

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is a progressive, degenerative spine disease that is often managed surgically. PURPOSE: The objective of this study was to conduct a systematic review to (1) summarize neurologic outcomes following surgical intervention; (2) evaluate whether outcomes are dependent on preoperative disease severity or duration of symptoms; and (3) to define the safety profile of surgery. STUDY DESIGN/SETTING: Systematic review. OUTCOME MEASURES: Neurologic outcomes, functional status, disability, quality of life and complications. METHODS: A systematic search was conducted in Embase, PubMed, and the Cochrane Collaboration for articles published between January 1, 1950 and February 9, 2015. Studies were included if they were prospective and if they evaluated clinical (mJOA, Nurick) disability (Neck Disability Index) or pain (Visual Analog Scale) outcomes in patients undergoing surgery for DCM. Studies were also included if they analyzed complications associated with surgical intervention. The quality of each study was evaluated using the Newcastle-Ottawa Scale and the strength of the overall body of evidence was rated using guidelines outlined by the Grading of Recommendation Assessment, Development and Evaluation Working Group (GRADE). RESULTS: Of the 385 relevant citations, 32 satisfied the inclusion criteria and were included in this review. Based on moderate quality evidence, surgical intervention results in significantly and clinically important improvement in JOA/mJOA in both the short- and long-term. Furthermore, surgery is associated with significant gains on the Nurick and NDI (low to very low quality of evidence). Patients with a shorter duration of symptoms have increased odds of achieving a score ≥16 on the mJOA. With respect to safety, pooled cumulative incidences were low for C5 radiculopathy or palsy (1.9%), infection (1.5%), reoperation (1.4%), dural tear/cerebrospinal fluid leak (1.4%), worsening of myelopathy (1.3%), death (0.3%) and pseudarthrosis or implant complication (2.1%). CONCLUSIONS: Surgical intervention is an appropriate treatment strategy for the management of DCM as it results in significant improvements in clinical status and is associated with a low rate of perioperative complications. Further work is important to define optimal surgical approach and timing.