Stability of Revision Total Hip Arthroplasty Implants Using Radiostereometric Analysis

The specific aim is to quantify the stability of the acetabular and femoral components of a revision total hip arthroplasty (THA) in vivo as currently performed at our institution. In this way, the investigators will gain insight into the outcome of the current state of the art of revision arthroplasty surgery. In the past, acetabular and femoral component stability has been measured using radiostereometric analysis (RSA) and when patients having revision total hip operations were compared to patients undergoing primary total hip operations it was possible to determine differences in stability and this was predictive of the intermediate to long-term performance of the acetabular and femoral reconstruction. The investigators propose to use this established, high resolution technique to assess and compare the stability of the revision implants.