Results with navigated bicontact total hip arthroplasty.

The position of the cup is crucial for the overall quality of a total hip arthroplasty. A malpositioning of the cup leads to increased risk of dislocation, wear, and revision. The position of the stem influences leg length and may cause impingement and dislocation. These faults may increase with minimally invasive procedures. From November 2001 to June 2005, 1081 consecutive THA patients were evaluated. Cup navigation resulted in a better alignment and additional improvement when the cup and stem were navigated. In stem navigation, a good control of the leg lengthening and a reliable prediction of the safe range of motion could be seen.