1. Haugesund Hospital, Helse Fonna HF, Orthopaedic
Department, Karmsundsgate 120, 5521 Haugesund, Norway.
2. The Norwegian Arthroplasty Register, Haukeland
University Hospital, Department of Orthopaedic
Surgery, Jonas Lies vei 65, 5021
Bergen, Norway.
3. Lovisenberg Diakonale Hospital, Lovisenberggata
17, N-0440 Oslo, Norway.
4. Haukeland University Hospital, Department
of Occupational Medicine, Jonas Lies vei 65, 5021
Bergen, Norway.
5. University of Bergen, Department
of Surgical Sciences, Institute of Medicine
and Dentistry, Jonas Lies vei 65, 5021
Bergen, Norway.