1. Center for Treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Oslo, Norway
2. Section for Public Health, Inland Norway University of Applied Sciences, Elverum, Norway
3. Department of Radiology, Sahlgrenska universitetssykehus, Göteborg, Sweden
4. Department of Rheumatology, University Hospital of North Norway, Tromsø, Norway
5. Lillehammer Hospital for Rheumatic Diseases, Lillehammer, Norway
6. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
7. Department of Radiology, Oslo University Hospital, Oslo, Norway
8. Department of Rheumatology, Oslo University Hospital, Oslo, Norway
9. Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland