1. Leiden University Medical Center, Department of Orthopedic Surgery, Postzone J11-70, PO Box 9600, 2300 RC Leiden, The Netherlands.
2. Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, Headington, Oxford OX3 7LD, UK.
3. Leiden University Medical Center, Department of Clinical Oncology, Postzone K1-P, PO Box 9600, 2300 RC Leiden, The Netherlands.
4. Leiden University Medical Center, Department of Radiology, Postzone C2-S, PO Box 9600, 2300 RC Leiden, The Netherlands.
5. John Radcliffe Hospital, Department of Radiology, Headley Way, Oxford OX3 9DU, UK.
6. Leiden University Medical Center, Department of Pathology, Postzone L1-Q, PO Box 9600, 2300 RC Leiden, The Netherlands.