1. Department of Orthopaedics and Trauma Surgery, Helsinki University Hospital, P. O. Box 266, FIN-00029, Helsinki, Finland.
2. Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, P. O. Box 57, FIN-00014, University of Helsinki, Finland.
3. Department of Pathology, Helsinki University Hospital, P. O. Box 400, FIN-00029, HUS (Helsinki), Finland.
4. Department of Paediatric Orthopaedics, Helsinki University Hospital, P. O. Box 281, FIN-00029, HUS (Helsinki), Finland.
5. Department of Orthopaedic Surgery and Research, Institute of Military Medicine Central Military Hospital, P. O. Box 50, FIN-00301, Helsinki, Finland.