1. Ter Gooi Hospital, Department
of Orthopaedics, P. O. Box 10016, 1201DA, Hilversum, the
Netherlands.
2. Nijmegen Medical Centre, Orthopaedic
Research Laboratory, Radboud University, P. O.
Box 9101, 6500 HM Nijmegen, the
Netherlands.
3. Sint Maartenskliniek Research, P.
O. Box 9011, 6500 GM Nijmegen, the
Netherlands.
4. Amphia Hospital, Molengracht
21, 4118 CK Breda, the Netherlands.