Total hip arthroplasty with dual-mobility components : a retrospective series of 25,545 primary cases.

Aims This registry-based study aimed to evaluate the long-term survivorship of dual-mobility components (DMCs) compared to conventional components (CCs) in primary total hip arthroplasty (THA), and to assess potential adverse effects, particularly in younger patients (aged < 75 years). Methods Data from 58,314 primary THAs recorded between January 2006 and December 2023 in the French national SOFCOT/RENACOT registry were analyzed, including 25,545 DMCs (46%). The primary outcome was revision for any cause. Kaplan-Meier survival curves and Cox proportional hazards models were used to compare implant survivorship, adjusting for age, sex, primary diagnosis, and fixation method. Results Among the 25,545 primary THAs performed with a DMC, 284 revisions (1.1%) were recorded. In adjusted Cox regression analysis, DMC use was not significantly associated with an increased risk of revision compared to CCs (hazard ratio 0.83 (95% CI 0.66 to 1.04); p = 0.118). Periprosthetic fracture was the leading cause of revision in the DMC group (98/284, 34.5%), occurring significantly more frequently than in the CC group (77/493, 15.6%; p < 0.001), while dislocation-related revisions were less common with DMCs. Overall, the combined proportion of revisions due to dislocation or fracture was lower in the DMC group (112/284, 39.4%) than in the CC group (254/493, 51.5%). No risk factors for implant failure were identified in multivariable Cox regression analysis. Conclusion DMCs provide excellent long-term survivorship and effectively reduce the risk of dislocation in primary THA. Although a higher incidence of periprosthetic fractures was observed with DMCs, the overall outcomes support their safe and effective use. Nevertheless, ongoing surveillance remains important to monitor these risks.