1. Edinburgh Orthopaedics, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK
2. Ageing and Health, Usher Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
3. Lothian Analytical Services, NHS Lothian, Edinburgh EH4 2XU, UK
4. Department of Emergency Medicine, Royal Infirmary Edinburgh, Edinburgh EH16 4SA, UK
5. Department of Orthopaedics and Usher Institute, University of Edinburgh, Little France, Edinburgh EH16 4SA, UK