A Comprehensive Meta-Analysis of the Adjacent Segment Parameters in Cervical Disk Arthroplasty Versus Anterior Cervical Discectomy and Fusion
Clinical Spine Surgery
Study Design: This is a meta-analysis of controlled trials. Objective: To assess the overall condition of adjacent segment of cervical disk arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF). Summary of Background Data: With the increase in CDA and ACDF, surgeons are taking more attention to adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis). There are more and more meta-analyses comparing the efficacy of CDA with ACDF, however, there are few
... ever, there are few meta-analyses referring to adjacent segment parameters, and investigators are still unable to arrive at the same conclusion. Methods: Several important databases were searched for controlled trials comparing CDA and ACDF before February 2016 according to PRISMA guidelines. The analysis parameters included follow-up time, operative segments, cervical range of motion (ROM), adjacent segment motion, ASDeg, ASDis and adjacent segment reoperation. The risk of bias scale and Newcastle-Ottawa Scale were used to assess the papers. Subgroup analysis and sensitivity analysis were used to analyze the reason for high heterogeneity. Results: Forty-one controlled trials fulfilled the inclusion criteria, including 36 English papers and 5 Chinese. The average follow-up time of all included patients was 39 months. Compared with ACDF, the rate of adjacent segment reoperation in the CDA group was significantly lower (P < 0.01), and the advantage of CDA group increased with the increasing of followup time according to subgroup analysis. The rate of ASDeg in CDA was significantly lower than that of ACDF (P < 0.01). There was no statistical difference between upper and lower ASDeg using the same surgical method (P > 0.05). CDA provided a greater cervical ROM than did ACDF (P < 0.01). There was a lower adjacent segment ROM and the rate of ASDis in CDA compared with ACDF (P < 0.05). Conclusions: Compared with ACDF, the advantages of CDA were lower ASDeg, ASDis, adjacent segment reoperation and adjacent segment motion; and higher cervical ROM. However, there was no statistical difference between upper and lower adjacent segment ROM/ASDeg using the same surgery. FIGURE 3. Forest plot comparing adjacent segment reoperation in CDA versus ACDF. Subgroup analysis with different follow-up time. ACDF indicates anterior cervical discectomy and fusion; CDA, cervical disk arthroplasty; CI, confidence interval.