Purpose
Instability is always an important problem after both primary and revision total hip arthroplasty (rTHA). Dual mobility or tripolar unconstrained acetabular components give a solution for preventing and treating instability. Results of many studies using dual mobility cups (DMC) with mid-term to long-term follow-up support their effectiveness. Complications such as intraprosthetic dislocation (IPD) and accelerated wear have been studied, although they seem to be less significant in older, low-demand patients. However, their use in younger patients should be with caution owing to the lack of current data concerning this high-demand patient population. The aim of this study is to analyze the short-term results of cemented DMCs in rTHA. Specifically, we evaluated the following: clinical outcomes and scoring, dislocation, IPD rates, and other complications.
Patients and methods
The results of a single design of DMC was prospectively evaluated in a continuous series of 20 rTHAs. Follow-up period was of at least 2 years. Mean age of the patients was 66.8 years old.
Results
At the 2-year mean follow-up, the dislocation rate was 5%, and the IPD rate was 0%. Improvement of the hip score, function, pain, and range of motion was noticed.
Conclusion
DMCs demonstrated a low dislocation rate in rTHA but did not solve problems related to perioperative technical errors. Moreover, IPD did not appear to be a concern when compared with the gain of preventing instability.