1. Swedish Hip Arthroplasty Register; Gothenburg Sweden
2. Department of Orthopaedics; Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg; Gothenburg Sweden
3. Department of Orthopedics; Sahlgrenska University Hospital; Gothenburg Sweden
4. Department of Orthopaedic Surgery; Capio St Göran; Stockholm Sweden
5. Futurum Academy; Ryhov Hospital; Jönköping Sweden
6. Swespine; Swedish Spine Register; Jönköping Sweden