1. Academic Department of Orthopaedic and Trauma Surgery, Leeds University, The General Infirmary at Leeds, Clarendon Wing, Great George Street, Leeds LS1 3EX, UK.
2. Orthopaedic Trauma Service Massachusetts General Hospital, YAW 3600, 55 Fruit Street, Boston, Massachusetts 02114, USA.
3. Division of Trauma University of Pittsburgh Medical Center, Pittsburgh 15213, USA.