1. Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
2. Department of Orthopaedic Surgery, Osaka City University Medical School, Abeno-Ku, Asahinachi, 1-4-3 Osaka 545-8585, Japan.
3. Department of Biomedical Engineering, University of Southampton, University Road, Highfield Road, Southampton SO17 1BJ, UK.
4. Biomaterials Laboratory, C12, BMC, Department of Orthopaedics, Lund University, S22184 Lund, Sweden.
5. Charles University, Prague, Czech Republic.
6. The Royal London Hospital, Whitechapel Road, London E1 4DG, UK.