The outcome of revision total hip arthroplasty for instability

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Instability is a frequent reason for revision total hip arthroplasty (THA).
• Recurrent dislocation can occur even after initial revision THA.
• Identifying risk factors for recurrent dislocation is crucial for improving patient outcomes.

Purpose of the Study:

• To assess the risk of recurrent dislocation following revision total hip arthroplasty (THA) for instability.
• To identify patient and surgical factors associated with recurrent dislocation after revision THA.

Main Methods:

• A cohort of 163 patients undergoing revision THA for instability between 2009-2019 was analyzed.
• Cox proportional hazard models were used to evaluate risk factors, considering death and infection as competing events.
• Patient-reported outcomes included VR-12, Harris Hip Score (HHS), and HOOS, JR.

Main Results:

• The cumulative incidence of recurrent dislocation was 8.7% at 1 year, 18.8% at 5 years, and 31.9% at 10 years.
• Significant risk factors included high American Society of Anesthesiologists (ASA) grade, BMI 25-30 kg/m², specialized liners, lumbopelvic stiffness, and abductor weakness.
• Increasing acetabular component size by >1 mm reduced dislocation risk (HR 0.89).

Conclusions:

• Patients undergoing revision THA for instability face a substantial risk of recurrent dislocation.
• Higher ASA grade, overweight status, prior lumbopelvic fusion, specialized liners, and postoperative abductor weakness are key risk factors.
• Optimizing component size and addressing identified risk factors may help mitigate recurrent dislocations.