1. Department of Molecular Medicine and Surgery, Section of Orthopaedics and Sports Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm;
2. Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm;
3. Functional Unit for Musculoskeletal Radiology, Function Imaging and Physiology, Karolinska University Hospital, Karolinska Institutet Stockholm, Sweden;
4. Department of Orthopaedic Surgery, Oregon Health Science University, Portland, Oregon, USA;
5. Section of Orthopaedics, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden