1. Department of Orthopedic Surgery, Oslo University Hospital, Ullevaal, Oslo, Norway
2. Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
3. Oslo Sport Trauma Research Center, Norwegian School of Sport Science, Oslo, Norway
4. Department of Orthopedic Surgery, Martina Hansens Hospital, Gjettum, Norway
5. Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway
6. Department of Orthopedic Surgery, Lovisenberg Diakonale Hospital, Oslo, Norway