1. Division of Orthopaedics, Department of Clinical Science Intervention and Technology (CLINTEC), Karolinska Institutet, S-141 86 Stockholm, Sweden
2. Department of Orthopaedics, Karolinska University Hospital/Huddinge, S-141 86 Stockholm, Sweden
3. Centre for Research Ethics and Bioethics, Uppsala University, P.O. Box 564, S-751 22 Uppsala, Sweden