Unique failure mechanism of a femoral component after revision total hip arthroplasty.

As the prevalence of revision total hip arthroplasty increases, the mechanisms of failure of these revisions have become better delineated. Several studies have indicated infection, instability, and aseptic loosening to be the more common mechanisms of failure in revision surgery. However, with increasing numbers of revisions performed, unique mechanisms of failure are being seen, likely related to the implants that are used in the revision setting. Revision implants offer certain advantages over primary implants with the use of modular components. The revision implants allow the surgeon to increase offset and leg length with modular femoral bodies and necks. However, these modular junctions represent additional areas for implant failure. These new methods of failure associated with modular implants are slowly presenting as the use of these implants continues to increase. The authors recently encountered a mechanism of failure that, to their knowledge, has not been described in the literature. They report a 57-year-old man with dissociation of the proximal body from the diaphyseal component of a Wright Medical Link (Memphis, Tennessee) stem prosthesis. The patient presented with an audible click on physical examination, and radiographs confirmed dissociation of the proximal body. The intraoperative findings, treatment method, and proposed mechanisms for this type of failure are presented, as well as insight into potential ways to avoid this type of failure.