Dual-Mobility Implants and Constrained Liners in Revision Total Hip Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Reconstructive Surgery

Background:

• Instability is the most frequent complication following revision total hip arthroplasty (THA).
• Comparing dual-mobility (DM) bearings and constrained liners (CL) is crucial for improving outcomes in revision THA.
• Understanding failure modes is key to optimizing implant selection.

Purpose of the Study:

• To compare aseptic revision rates and survivorship between DM and CL in revision THA.
• To identify risk factors associated with implant failure in revision THA.
• To evaluate the efficacy of DM versus CL in managing hip instability.

Main Methods:

• Retrospective review of 191 revision THA patients (2008-2019) who received either CL or DM bearings.
• Comparison of patient demographics, comorbidities, indications, dislocations, and aseptic failure rates.
• Bivariate and multivariate regression analyses, alongside Kaplan-Meier survivorship analysis for aseptic re-revision.

Main Results:

• No statistically significant difference in dislocation rates (10.4% vs 14.0%) between DM and CL groups.
• Aseptic revision rates (30.9% vs 46.2%) and time to revision did not significantly differ.
• Multivariate analysis indicated no significant difference in aseptic re-revision rates between CL and DM (OR 1.47, P=0.177).

Conclusions:

• Both CL and DM bearings exhibit high aseptic failure rates at intermediate follow-up in revision THA.
• Constrained liners (CL) demonstrated a trend toward higher failure risk compared to dual-mobility (DM) bearings, though not statistically significant.
• Further prospective studies are required to establish the optimal bearing choice for managing recurrent instability in revision THA.