Inverted cup prosthesis to treat recurrent hip dislocation in frail elderly patients.

Recurrent hip dislocation has become an increasing problem in patients who had multiple component revision in total hip arthroplasty. These are often frail elderly patients with loss of constraining soft tissue envelope around the hip and an excessive weakness of the abductor mechanism. We present a simple technique for open reduction of a dislocated hip using a custom-made fully constrained construct with potential for preserving the well fixed femoral implant and parts of the acetabular component. The custom-made constrained construct consists of the application of an inverted cup over the femoral neck or head, the cup being fixed to the acetabular insert with screws. Three frail elderly patients have been successfully treated. One specific case is described in detail. In frail elderly patients who may have undergone several revision surgeries, it is important to preserve components of the total hip replacement when possible. The proposed technique may be an alternative solution for these patients.