Purpose: Although many meta-analyses have been performed to compare total disc replacement (TDR) and fusion for treating lumbar degenerative disc disease (LDDD), their findings are inconsistent. This study aimed to conduct a systematic review of overlapping meta-analyses comparing TDR with fusion for treating LDDD, to assist decision makers in selection among conflicting meta-analyses, and to provide treatment recommendations based on the best available evidence.
Methods: This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Multiple databases were comprehensively searched for meta-analyses comparing TDR with fusion for treating LDDD. Meta-analyses only comprising randomised controlled trials (RCTs) were included. Two authors independently assessed meta-analysis quality and extracted data. The Jadad decision algorithm was used to ascertain which meta-analyses represented the best evidence.
Results: A total of five meta-analyses were included. All these studies only included RCTs were determined as Level-II evidence. The scores of Assessment of Multiple Systematic Reviews (AMSTAR) ranged from 6 to 9 (median 7). A high-quality Cochrane review was chosen according to the Jadad algorithm. This best available evidence found that statistical significances were observed between TDR and fusion for LDDD regarding disability, pain relief, and pain in the short term, but it was not over clinically important differences. The prevent effects on adjacent segment and facet joint degeneration, as the primary goal of adopting TDR stated by the manufacturers, were not appropriately evaluated.
Conclusions: There is discord in results from meta-analyses that assessed TDR and fusion for LDDD. According to this systematic review of overlapping meta-analyses comparing TDR and fusion for LDDD, the current best available evidence suggests that TDR may be an effective technique for the treatment of selected patients with LDDD, and is at least equal to lumbar fusion in the short term. However, considering that disadvantages may appear after years, spine surgeons should be cautions about performing TDR on a large scale.
Keywords: Lumbar degenerative disc disease; Lumber fusion; Meta-analysis; Total disc replacement.