1. Bent Erling Lindblad, The University Department of Orthopedic Surgery, Aarhus County Hospital, Denmark, Address for offprints: Bent Erling Lindblad, M.D. University Department of Orthopedic Surgery Aarhus County Hospital, Tage Hansensgade 2 DK-8000 Aarhus C, Denmark
2. The University Department of Orthopedic Surgery, Randers City Hospital, Denmark
3. The Accident Analysis Center of the County of Aarhus, Denmark.