23 hips (15.1%) needed revision surgery. The majority (17 hips – 73.9% of all reoperations) were revised due to progressive Polyethylene wear, all after a minimum of ten years. Exchange of the polyethylene inlay and the ceramic head was performed in 14 hips. In two cases the acetabular component and in one case the femoral component were found to be loose intraoperatively because of the wear debris and had to be exchanged. 4 hips had to be revised due to aseptic cup loosening without signs of increased polyethylene wear. There was one revision due to a late deep infection and one because of a periprothetic femoral fracture.