Status of navigated total hip arthroplasty in dysplastic osteoarthritis

This article describes the results of 41 total hip arthroplasties (THAs) carried out using a new image-free hip navigation system. For the study, registration landmarks (tear drop, posterior rim, and inner wall of the acetabulum) were added to the hip navigation system OrthoPilot (B. Braun Aesculap, Tuttlingen, Germany). The reamer center was indicated in reference to these landmarks, and final cup angle was indicated as the radiologic angle. Forty-one total THAs to treat dysplastic osteoarthritis of the hip were performed. The difference between reamer center and cup center was 4.1 +/- 3.0 mm. The difference in cup abduction angle between navigation and radiography was 6.4 degrees +/- 5.1 degrees and of anteversion was 5.9 degrees +/- 5.0 degrees. Our preliminary clinical results showed adequate accuracy.