How Effective Are Constrained Liners at Preventing Dislocation After Revision Total Hip Arthroplasty?

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Reconstructive Surgery

Background:

• Recurrent hip instability poses a significant challenge in revision total hip arthroplasty (rTHA).
• Constrained liners (CL) are employed to manage recurrent or multidirectional instability in rTHA cases.
• Evaluating the efficacy of CL prostheses in rTHA is crucial for improving patient outcomes.

Purpose of the Study:

• To assess the dislocation rates associated with CL prostheses in rTHA.
• To determine the survivorship of CL prostheses following rTHA.
• To identify factors influencing dislocation and reoperation rates in rTHA with CL.

Main Methods:

• Retrospective review of 98 rTHAs utilizing CL prostheses (2013-2024).
• Exclusion criteria included antibiotic spacers, megaprostheses, and follow-up less than one year.
• Survivorship analyses were conducted for dislocation and reoperation-free outcomes over a mean follow-up of 3.9 years.

Main Results:

• The final dislocation rate for CLs was 16.3% (16/98), with a nine-year dislocation-free survivorship of 71%.
• No significant differences in dislocation-free survivorship were found based on CL system, cup status, or fixation method.
• The overall reoperation rate was 49.0% (48/98), with nine-year all-cause reoperation-free survivorship at 33%; infection and instability were primary reoperation reasons.

Conclusions:

• Constrained liners (CL) act as a salvage option for preventing dislocations in revision total hip arthroplasty (rTHA) with instability.
• Despite their role in preventing dislocations, CLs are associated with high rates of both dislocation and reoperation.
• Further research is warranted to optimize CL performance and reduce reoperation rates in complex rTHA cases.