1. Department of Orthopaedics, Ortopediska Huset, Stockholm, Sweden
2. Department of Orthopaedics, Läkarhuset Odenplan, Stockholm, Sweden
3. Department of Orthopaedics, Visby Hospital, Visby & Stockholm Sports Trauma Research Center, Karolinska Institutet, Stockholm, Sweden
4. Department of Orthopaedics, St Görans Hospital, Stockholm, Sweden