For patients who suffer from end stage of osteoarthritis of the hip, a joint replacement could result in an obvious improvement of the quality of life. However, because of the life expectation and high level of activity of young and active patients, the conventional total hip replacement does not offer an optimal solution.~An alternative to a total hip replacement in young and active patients is the resurfacing hip prostheses. The articular surface replacement (ASR) hip prostheses can be placed by the conventional positioning method and by using 'computer assisted surgery' (CAS). The hypothesis is that the positioning of the femoral component by the conventional positioning method will show a larger variation between pre planned and actual position than when CAS is used.~This study will compare the results of those who had an ASR prosthesis placed by the conventional positioning method with those patients in whom the ASR prosthesis was placed using CAS.
The purpose of this study is to compare the articular surface replacement (ASR) prosthesis placed by the conventional positioning method and the ASR prosthesis placed by 'computer assisted surgery' (CAS) in variation between pre planned position of the femoral component and the actual position of the femoral component of the prosthesis. The hypothesis is that this variation is larger with the conventional positioning method than when CAS is used.