1. Department of Orthopaedic Surgery, Borders General Hospital, Huntlyburn, Melrose TD6 9BS, UK
2. School of Biological Sciences, University of Edinburgh, Darwin Building, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
3. Department of Orthopaedic Surgery, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Old Dalkeith Road, Edinburgh EH16 4SB, UK
4. Department of Orthopaedic Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Old Dalkeith Road, Edinburgh EH16 4SA, UK