1. The Orthopaedic Research Unit Department of Orthopaedic Surgery and Traumatology Odense University Hospital Odense Denmark
2. Department of Clinical Research University of Southern Denmark Odense Denmark
3. H.C. Andersen Children's Hospital Odense University Hospital Odense Denmark
4. Department of Paediatrics Lillebaelt Hospital Kolding Denmark
5. Department of Paediatrics Hospital of Western Jutland Esbjerg Denmark