The importance of acetabular component position in total hip arthroplasty.

Correct acetabular cup position is critical to successful total hip replacement. Unfortunately, malposition of acetabular cups is common and leads to increased rates of dislocation, wear, and ion toxicity. Despite the popularity of Lewinnek's safe zone, the exact target of acetabular abduction and version remains elusive. Differences in functional pelvic position, surgical approach, and femoral anteversion affect the optimal cup position for individual patients. Surgeons need to be aware of pelvic position changes from the supine to lateral decubitus position.