1. Department of Pediatric and Adolescent Surgery, Pediatric Clinics and Pediatric Research Center, Tampere University Hospital, Tampere, Finland
2. Division of Orthopedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, Tampere, Finland
3. Department of Orthopedics, Karolinska Hospital, Stockholm, Sweden
4. Department of Pediatric Surgery, Pediatric Clinics, Turku University Hospital, Turku, Finland