1. Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Centre for Head and Orthopaedics, Rigshospitalet, Copenhagen, Denmark
2. Department of Clinical Medicine, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
3. Center for Rheumatology and Spine Diseases, Centre for Head and Orthopaedics, Rigshospitalet, Copenhagen, Denmark
4. The DANBIO Registry, Center for Rheumatology and Spine Diseases, Centre for Head and Orthopaedics, Rigshospitalet, Copenhagen, Denmark
5. Department of Radiology, Rigshospitalet Glostrup, Copenhagen, Denmark
6. Department of Radiology, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
7. Department of Radiology, Herlev and Gentofte Hospital, Copenhagen, Denmark
8. Zitelap Aps, Copenhagen, Denmark