Reduction in Variability of Acetabular Cup Abduction Using Computer Assisted Surgery: A Prospective and Randomized Study

Abstract

Optimal orientation of the acetabular component of a total hip prosthesis is an important factor in determining the early and long-term result of a total hip arthroplasty (THA). Conventional positioning of the cup component is usually done using a free-hand method, or with the help of a mechanical acetabular alignment guide. However, these methods have proven to be inaccurate, and a great variation in orientation of the cup is found postoperatively. In this study, we wished to determine if the variability of the abduction angle of acetabular cups could be reduced with the use of computer navigation. The abduction angles of the acetabular components of three groups of 50 THAs were assessed. In the first group, a free-hand method was used to position the cup component. This group was operated in the period before we started using computer navigation for hip surgery. In the second group, CT-based computer navigation was used to plan and help position the cup. The third group consisted of 50 THA cases in whic...