1. Department of Orthopaedic Surgery, Skeletal Tissue Engineering Group Amsterdam (STEGA)
2. Department of Physics and Medical Technology STEGA Vrije Universiteit Medical Centre, P O Box 7057, 1007 MB Amsterdam, The Netherlands.
3. The Centre for Biomedical Engineering, Institute of Orthopaedics and Musculo-Skeletal Science, University College London, RNOH Trust, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.