デュアルモビリティコンポーネントを用いた股関節全置換術：25,545例の一次手術の後ろ向きコホート研究

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).

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.

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.

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.