Zero-profile implant versus conventional cage-plate construct in anterior cervical discectomy and fusion for the treatment of single-level degenerative cervical spondylosis: a systematic review and meta-analysis

Background The clinical outcomes of single-level anterior cervical discectomy and fusion (ACDF) with the Zero-profile (Zero-p) were evaluated in comparison with the anterior cervical cage-plate construct (CPC). Methods We performed a systematic search covering PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Medline, China National Knowledge Infrastructure (NCKI), Wan Fang Database, and Wei Pu Database. Articles focused on single-level ACDF or data of the single - level that can be extracted were included, and articles that did not directly compare Zero-p and CPC were excluded. Twenty-seven studies were included with a total of 1866 patients, 931 in the Zero-p group and 935 in the CPC group. All outcomes were analyzed using Review Manager 5.4. Results The meta-analysis outcomes indicated that operative time (WMD = - 12.47, 95% CI (- 16.89, - 8.05), P < 0.00001), intraoperative blood loss (WMD = - 13.30, 95% CI (- 18.83, - 7.78), P < 0.00001), risk of adjacent segment degeneration (ASD) (OR 0.31, 95% CI (0.20, 0.48), P < 0.0001), risk of dysphagia of short-term (OR 0.40, 95% CI (0.30, 0.54), P < 0.0001), medium-term (OR 0.31, 95% CI (0.20, 0.49), P < 0.0001), and long-term (OR 0.29, 95% CI (0.17, 0.51), P < 0.0001) of Zero-p group were significantly lower. The JOA score of Zero-p group at the final follow-up was significantly higher (WMD = - 0.17, 95% CI (- 0.32, - 0.03), P = 0.02). There were no significant differences in length of stay (LOS), Neck Disability Index (NDI), Visual Analogue Score (VAS), fusion rate, segmental Cobb angle, cervical Cobb angle, prevertebral soft tissue thickness (PSTT), SF-36, subsidence, implant failure, and hoarseness between the two groups. This study was registered with PROSPERO, CRD42022347146. Conclusion Zero-p group reduced operative time, intraoperative blood loss, JOA score at follow-up and reduced the incidence of dysphagia and postoperative ASD, but the two devices had the same efficacy in restoring the cervical curvature, preventing the cage subsidence, and in postoperative VAS, NDI, LOS, PSTT, SF-36, fusion rate, implant failure, and hoarseness in single-level ACDF. The use of Zero-p in single-level ACDF was recommended.