1. Section for Sports Traumatology M51 Bispebjerg and Frederiksberg Hospital Copenhagen Denmark
2. The Research Unit for General Practice and Section of General Practice Department of Public Health University of Copenhagen Copenhagen Denmark
3. Primary Health Care Research Unit Region Zealand, Sorø Denmark
4. Section of Biostatistics Department of Public Health University of Copenhagen Copenhagen Denmark
5. Orthopedic Clinic Oslo Sports Trauma Research Center University of Oslo Medical School Oslo Norway
6. Norwegian National Knee Ligament Registry Department of Orthopedic Surgery Haukeland University Hospital Bergen Norway
7. Oslo Sports Trauma Research Center Norwegian School of Sports Sciences Oslo Norway
8. Department of Molecular Medicine and Surgery Stockholm Sports Trauma Research Center Karolinska Institute Stockholm Sweden