1. Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet, Stockholm
2. Department of Orthopedics, Danderyds Hospital, Stockholm
3. Department of Surgical Sciences, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
4. Institute of Clinical Medicine, University of Oslo, Oslo
5. Division of Orthopedic Surgery, Oslo University Hospital, Oslo
6. Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway
7. Department of Orthopedic Surgery and Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
8. Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden
9. Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm
10. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm
11. Department of Orthopaedic Surgery, Østfold Hospital Trust, Grålum, Norway