1. Department of Orthopaedics Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZN, UK.
2. Scottish Hip Fracture Audit Healthcare Information Group, Information Services Division, NHS National Services Scotland, Gyle Square, 1 South Gyle Crescent, Edinburgh EH12 9EB, UK.
3. Department of Surgery and Orthopaedics University of Aberdeen Medical School, Polwarth Building, Foresterhill, Aberdeen AB25 2ZD, UK.