Anterior Cervical Discectomy and Fusion with Zero-Profile Anchored Spacer Versus Plate and Cage for 3-Level Contiguous Cervical Degenerative Disease: A Systematic Review and Meta-Analysis

OBJECTIVE: To compare the safety, clinical outcomes, and radiological results of anterior cervical discectomy and fusion (ACDF) with zero-profile anchored spacer (ZPAS) versus plate and cage (PC) for 3-level contiguous cervical degenerative disease. METHODS: The study was registered at PROSPERO (CRD42024512706). The Web of Science core collection, PubMed, and Embase were searched up to February 12, 2024. Review Manager 5.3 was used. The relative risk (RR) and 95% confidence interval were evaluated for dichotomous data. Continuous data were assessed using the mean difference and 95% confidence interval. RESULTS: Nine studies comparing ACDF with ZPAS versus PC for 3-level contiguous cervical degenerative disease were included. The intraoperative blood loss and operation time in ZPAS were significantly less than those in PC. The subsidence rate, loss of cervical alignment, fusion segmental height, and intervertebral disc height were significantly greater in ZPAS than in PC. The cervical alignment and dysphagia rate within 6 months were significantly lower in ZPAS than in PC. The ASD of ZPAS was significantly lower than that of PC according to the sensitivity analysis when 1 study was excluded. No significant differences were identified in the other aspects. CONCLUSIONS: Both ACDF with ZPAS and PC were safe and effective procedures. PC was associated with increased surgical trauma. The ZPAS could better decrease the incidence of ASD and dysphagia. ZPAS was also accompanied by high subsidence rate and poor cervical alignment.