1. Department of Clinical Medicine Aarhus University Aarhus Denmark
2. Department of Children's Orthopaedic Surgery Aarhus University Hospital Aarhus Denmark
3. DEFACTUM, Central Denmark Region Aarhus Denmark
4. Department of Public Health Aarhus University Aarhus Denmark
5. Aalborg University Hospital Aarhus Denmark
6. Division of Orthopaedic Surgery & Child Health Evaluative Sciences The Hospital for Sick Children Toronto Ontario Canada
7. University of Toronto Toronto Ontario Canada