1. Department of Pediatric and Adolescent Surgery, Pediatric Clinics and Pediatric Research Centre, Tampere University Hospital, Teiskontie 35, 33521, Tampere Finland
2. Department of Pediatric Surgery, Pediatric Clinics, Turku University Hospital, Turku Finland
3. Division of Orthopedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, Tampere Finland
4. Department of Orthopedics, Karolinska Hospital, Stockholm Sweden