Abstract
Hip dislocation and recurrent instability continue to be a major cause of failure despite advances in materials to optimise offset and head size. The most common cause of revision after total hip arthroplasty (THA) remains recurrent dislocation (22.5%). Dislocation rates following revision THA are even higher than primary THA, and can be as high as 27%.
Dual mobility acetabular components were introduced in 1974 by Bousquet to reduce dislocation risk and maintain the low friction concept introduced by Charnley. Dual mobility THA has gained wide acceptance in Europe, but there are still concerns regarding its long-term outcomes in the United States. However, even with noncrosslinked polyethylene and poor implant design, survivorship at 22 years has been shown to be 75%.
Little has been published on modular dual mobility (MDM) THA in the revision setting. During revision THA, the benefits of enhanced stability may outweigh the risks of potential unforeseen complications. We present the early results of MDM revision THAs with a low complication rate. In our series, we had a 1.6% dislocation rate, which is significantly lower than what has been published in the literature. However, we urge caution with its use in off label cases, as one of the dislocations was intraprosthetic upon attempted reduction requiring revision to a constrained liner.
