H1 Hip Resurfacing Arthroplasty

Inclusion Criteria: * Patient requires primary hip arthroplasty due to degenerative joint disease (primary osteoarthritis, posttraumatic osteoarthritis, avascular necrosis, developmental hip dysplasia) * Patient is eligible for hip resurfacing arthroplasty: i.e. has sufficient bone stock at the level of the femoral head (\<1/3 necrosis of the head) and neck (not osteopenic/porotic, see exclusion criteria) * Patient is between 18 and 70 years old * Patient willing to comply with study requirements * Patient is legally entitled and able to consent, agrees to consent to and to follow the study visit schedule (as defined in the study protocol and informed consent form), by signing the informed consent form approved by the Ethics Committee. * Patient plans to be available through ten (10) years postoperative follow-up * Patient is able to understand the native language of the country of the trial centre Exclusion Criteria: * Patient has a BMI greater than 40 * Patient suffers from an active inflammatory joint disorder * Patient has an active infection or sepsis (treated or untreated) * Patient has insufficient bone stock at the hip (\>1/3 necrosis of the femoral head) or in general as in severe osteopenia or osteoporosis (Tscore \< -2.5 as measured with BMD) * At the time of enrolment, patient has one or more of the following arthroplasties that have been * Implanted less than 6 months before the current hip arthroplasty: * Contralateral primary total hip arthroplasty or hip re…