Dual-mobility implants in primary and revision total hip arthroplasty: A systematic review and meta-analysis.

Purpose: Total hip arthroplasty (THA) is a common and successful operation. However, dislocation remains a significant cause of implant failure in fixed-bearing designs. This study investigated the effect of dual-mobility implants (DM) compared to fixed-bearing (FB) implants on all-cause revisions, revisions due to dislocation, post-operative complications and functional scores in patients undergoing primary and revision THA. Methods: A systematic review was performed including studies that compared DM with FB implants in primary or revision THA according to PRISMA guidelines, and was registered in PROSPERO (ID CRD42023403736). The Cochrane Library, Embase, MEDLINE, Web of Science, and Scopus were searched from the time of database inception to March 12, 2023. Eligible studies underwent meta-analysis and risk of bias assessment using the ROBINS-I tool. Treatment effects were assessed using odds ratios and data were pooled using a random-effects maximum-likelihood, where appropriate. Results: Eight comparative, non-randomised studies involving 2810 DM implants and 3188 FB implants were included. In primary THA, there was an imprecise estimate of the difference in all-cause revision (OR 0.82, 95 % CI 0.25-2.72) and a significant benefit for the DM cohort in revision due to dislocation (OR 0.08, 95 % CI 0.02-0.28). In revision THA, the DM cohort showed benefit in all-cause revision (OR 0.57, 95 % CI 0.31-1.05) and revision due to dislocation (OR 0.14, 95 % CI 0.04-0.53). DM implants were associated with a lower incidence of implant dislocation and infection. The analysis of functional outcomes was limited due to reporting limitations. No intraprosthetic dislocations were observed. Conclusion: The results suggest that contemporary DM designs may be advantageous in reducing the risk of all-cause revision, revision due to dislocation, and post-operative complication incidence at mid-term follow-up. Further high-quality prospective studies are needed to evaluate the long-term risk profile of this design, especially in the revision context.