Incidence of dysphagia of zero-profile spacer versus cage-plate after anterior cervical discectomy and fusion: A meta-analysis

BACKGROUND: The purpose of this study is to evaluate the rate of dysphagia between zero-profile spacer versus cage-plate for the treatment of multilevel cervical spondylotic myelopathy (CSM). METHODS: The authors searched electronic databases for relevant studies that compared the clinical effectiveness of zero-profile spacer versus cage-plate for the treatment of patients with multilevel CSM. The following outcome measures were extracted: the Japanese Orthopaedic Association (JOA) scores, Neck Disability Index (NDI) score and fusion rate, dysphagia rate, adjacent segment degeneration, and cervical lordosis. Newcastle-Ottawa Quality Assessment Scale was used to evaluate the quality of each study. Data extraction and quality assessment were conducted, and RevMan 5.2 was used for data analysis. RESULTS: A total of 10 studies were included in our meta-analysis. Our pooled data revealed that zero-profile spacer was associated with decreased dysphagia rate at postoperatively 1, 3, and 6 months, and the final follow-up when compared with cage-plate group. No significant difference was observed in terms of postoperative JOA score, NDI score, and fusion rate. Compared with zero-profile spacer, the postoperative adjacent segment degeneration was significant higher in cage-plate. Pooled data from the relevant studies revealed that cervical lordosis was significantly lower in zero-profile spacer compared with cage-plate. CONCLUSIONS: Our meta-analysis reveals zero-profile spacer is better than the cage-plate in terms of dysphagia. This suggests zero-profile spacer is a superior alternative invention for the treatment of multilevel CSM to reduce the risk of dysphagia.