Cervical disc arthroplasty versus anterior cervical discectomy and fusion for treatment of symptomatic cervical disc disease: a meta-analysis of randomized controlled trials

The purpose of this study is to compare the effectiveness and safety of cervical disc arthroplasty with anterior cervical discectomy and fusion for treatment of symptomatic cervical disc disease. Anterior cervical discectomy and fusion (ACDF) is the conventional surgical treatment for symptomatic cervical disc disease. Recently, cervical disc arthroplasty (CDA) has been developed to address some of the shortcomings associated with ACDF by preserving function of the motion segment. Controversy still surrounds regarding whether CDA is better. We systematically searched six electronic databases (Medline, Embase, Clinical, Ovid, BIOSIS and Cochrane registry of controlled clinical trials) to identify randomized controlled trials (RCTs) published up to April 2014 in which CDA was compared with ACDF for the treatment of symptomatic cervical disc disease. Effective data were extracted after the assessment of methodological quality of the trials. Then, we performed the meta-analysis. Eighteen relevant RCTs with a total of 4061 patients were included. The results of the meta-analysis indicated that CDA was superior to ACDF regarding better neurological success (P < 0.00001), greater motion preservation at the operated level (P < 0.00001), fewer secondary surgical procedures (P < 0.00001), and fewer rates of adverse events (P < 0.00001) but inferior to ACDF regarding operative times (P < 0.00001). No significant difference was identified between the two groups regarding blood loss (P = 0.87), lengths of hospital stay (P = 0.76), neck pain scores (P = 0.11) and arm pain scores (P = 0.78) reported on a visual analog scale. The meta-analysis revealed that CDA demonstrated superiorities in better neurological success, greater motion preservation at the operated level, lower rate of adverse events and fewer secondary surgical procedures compared with ACDF. However, the benefits of blood loss, lengths of hospital stay, neck and arm pain functional recovery are still unable to be proved.