Two- and five-year follow-up of lumbar total disc replacement compared to fusion: a meta-analysis

Lumbar fusion surgery has been a gold standard for treating lumbar disc degenerative disease (LDDD). But the adjacent segment pathology (ASP) became a problem, which could have been caused by the increased motion and stress concentration at the adjacent segment. So, artificial total disc replacement (TDR) as an alternative to spinal fusion has recently been applied for treatment of LDDD. However, up to now, a controversy whether TDR is better than fusion still persists. We performed the research of database including Pubmed/Medline, EMBASE, and Ovid. Our studies were classified into short-term (2 years) and midterm (5 years) follow-up. Twelve randomized controlled trials involving 1479 cases were included in the study. The repetitive data from them were excluded. Significant difference in visual analogue scale (VAS) and Oswestry disability index (ODI) could be found at 2 year follow-up, and TDR group was better than fusion group in both of them (VAS: I-2=0%, P<0.0006; ODI: I-2=0%, P<0.00001). No difference was found in reoperation rate at 2 year follow-up (I-2=18%, P=0.22). However, the reoperation rate at the index level in TDR group was significantly lower than that in fusion group at 5 year follow-up (I-2=0%, P=0.006). The incidence of ASP in TDR group was lower compared with fusion group at 5 year follow-up (I-2=0%, P<0.0002) but not at 2 year follow-up (I-2=0%, P<0.08). TDR shows the efficacy and safety comparable to lumbar fusion at 2 and 5 year follow-up. Besides, TDR has significant superiority in a lower incidence of ASP at 5 year follow-up.