Combining All Available Clinical Outcomes on Cervical Disc Arthroplasty: A Systematic Review and Meta-Analysis

Abstract

Background: Reviews of total disc arthroplasty (TDA) performance have focused on prospective randomized controlled trials (RCTs), excluding potentially important clinical information reported by others. The goal of the present study was to perform a comprehensive review, including both RCTs and non-randomized cohorts with more than five years of clinical outcome. We further explored the differences in outcome between prospective RCT and non-randomized, including retrospective studies. Methods: A systematic literature review was performed following PRISMA guidelines. Inclusion criteria were: clinical follow-up ≥ 5 years with quantitative clinical and radiographic outcome. All studies that met these criteria, including retrospective and non-randomized studies, were included, for a total of 62 studies. As anterior cervical discectomies and fusion (ACDF) was included as a control group in the majority of the studies, comparisons between TDA and ACDF were conducted. Results: Overall, there was a statistically significant difference between the rates of secondary surgeries reported for prospective RCTs and all other studies, with reoperation rates of 5.4% for prospective RCT studies v. 7.5% in all others (P<0.01). Including all studies, the reoperation rate for TDA patients was 5.6% and for fusion patients (included as control groups), 7.8%, (P=0.06). Overall, the reported incidence of adjacent segment degeneration was 26.2% in TDA patients and 43.9% in fusion patients (P<0.001). Conclusions: These findings demonstrated the need for including all available data to assess the current outcomes of cervical disc arthroplasty and account for potential biases.