1. Lennart Dimberg, Volvo Flygmotor AB, Trollhättan, Sweden, Address for offprints: Lennart Dimberg Volvo Flygmotor AB S-46181 Trollhättan Sweden
2. Orthopaedic Department, F.S.A., Akureyri, Iceland
3. Department of Handsurgery, Sahlgren Hospital, Gothenburg, Sweden
4. Volvo Flygmotor AB, Trollhättan, Sweden
5. Department of Orthopaedic Surgery, Chicago, III., USA,
6. Kungälv, Sweden, Rush-Presbyterian-St Luke's Medical Center
7. Faculty of Medicine, University of Kuwait
8. Department of Orthopaedics, Sahlgren Hospital, Gothenburg, Sweden