1. Department of Orthopaedics and Traumatology, North Kymi Hospital, Kuusankoski, Finland
2. Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Helsinki, Finland
3. Center for Injury and Violence Prevention, Kouvola Health Center, Kouvola, Finland
4. Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland
5. Department of Orthopaedics and Traumatology, Päijät-Häme Central Hospital, Lahti, Finland
6. National Institute for Health and Welfare, Helsinki, Finland