Acetabular Revision With Dual-Mobility Bearing Reduces Redislocation in Unstable Total Hip Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Arthroplasty Research

Background:

• Revision total hip arthroplasty (R-THA) for instability faces significant redislocation rates (21-39%).
• Strategies like large femoral heads, constrained liners (CL), or dual-mobility (DM) implants are employed to mitigate instability.
• This study evaluated redislocation and re-revision risks following R-THA for instability and identified failure risk factors.

Purpose of the Study:

• To assess cumulative redislocation and re-revision rates after R-THA for instability.
• To identify patient and surgical risk factors associated with R-THA failure due to instability.
• To compare the effectiveness of different implant strategies in preventing redislocation.

Main Methods:

• A retrospective analysis of 472 hips (468 patients) undergoing first-time R-THA for instability (2006-2021).
• Dual-mobility (DM) bearings were utilized post-2010; data included patient demographics, surgical factors, and management strategies.
• Survival endpoints were time to redislocation and re-revision, with cumulative risks and hazard ratios (HR) calculated.

Main Results:

• Five-year cumulative redislocation and re-revision risks were 20% and 22%, rising to 24% and 38% at 10 years.
• Risk factors for redislocation/re-revision included non-osteoarthritis THA (HR 2.45/2.36), smoking (HR 2.93/2.37), and cup retention (HR 1.84/1.99).
• Cup revision with a DM implant showed the lowest 5-year redislocation incidence (7%), outperforming other strategies.

Conclusions:

• R-THA for instability remains challenging, with high reoperation and rerevision rates.
• Patient optimization (e.g., smoking cessation) and appropriate acetabular component revision are recommended.
• Consideration of dual-mobility (DM) or constrained liner (CL) implants is advised to reduce redislocation.