Catastrophic failure of a modular revision total hip polyethylene insert.

Abstract

Early catastrophic failure of a modular polyethylene component is a potential problem after revision total hip arthroplasty. We describe an unusual case of polyethylene failure that occurred within 18 months of implantation in which no obvious technical error or mechanical failure was identified. The acetabular polyethylene insert was prepared with gas plasma sterilization, and the shelf life was 4 months. Radiographic evaluation used generalized Hough transforms to assess the cup articulation. We identified cup penetration of 2.8 mm before revision and catastrophic destruction of the polyethylene liner at the time of revision. Possible factors implicated for failure included a thin polyethylene liner, increased hip separation, femoral head mismatch, and the high activity level of a younger patient. We believe that this case report highlights the need for future investigations of these subtle factors.