1. Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
2. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0ES, UK
3. School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
4. Clinical Sciences & Services, Royal Veterinary College, London NW1 0TU, UK
5. Small Animal Specialist Hospital, Alexandria, Sydney, NSW 2015, Australia
6. Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Sydney NSW 2052, Australia