Artificial total disc replacement versus fusion for lumbar degenerative disc disease: a meta-analysis of randomized controlled trials

The purpose of this study is to compare the effectiveness and safety of artificial total disc replacement (TDR) with fusion for the treatment of lumbar degenerative disc disease (DDD). Spinal fusion is the conventional surgical treatment for lumbar DDD. Recently, TDR has been developed to avoid the negative effects of the fusion by preserving function of the motion segment. Controversy still surrounds regarding whether TDR 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 March 2013 in which TDR was compared with the fusion for the treatment of lumbar DDD. Effective data were extracted after the assessment of methodological quality of the trials. Then, we performed the meta-analysis. Seven relevant RCTs with a total of 1,584 patients were included. TDR was more effective in ODI (MD -5.09; 95 % CI [-7.33, -2.84]; P < 0.00001), VAS score (MD -5.31; 95 % CI [-8.35, -2.28]; P = 0.0006), shorter duration of hospitalization (MD -0.82; 95 % CI [-1.38, -0.26]; P = 0.004) and a greater proportion of willing to choose the same operation again (OR 2.32; 95 % CI [1.69, 3.20]; P < 0.00001). There were no significant differences between the two treatment methods regarding operating time (MD -44.16; 95 % CI [-94.84, 6.52]; P = 0.09), blood loss (MD -29.14; 95 % CI [-173.22, 114.94]; P = 0.69), complications (OR 0.72; 95 % CI [0.45, 1.14]; P = 0.16), reoperation rate (OR 0.83; 95 % CI [0.39, 1.77]; P = 0.63) and the proportion of patients who returned to full-time/part-time work (OR 1.10; 95 % CI [0.86, 1.41]; P = 0.47). TDR showed significant safety and efficacy comparable to lumbar fusion at 2 year follow-up. TDR demonstrated superiorities in improved physical function, reduced pain and shortened duration of hospitalization. The benefits of operating time, blood loss, motion preservation and the long-term complications are still unable to be proved.