1. Department of Orthopaedic and Trauma Surgery, Campus Biomedico University, Via Alvaro del Portillo 200, 00128 Trigoria, Rome, Italy.
2. London Independent Hospital, Stepney Green, London E1 4NL, UK
3. Department of Orthopaedic and Trauma Surgery, University Hospital of North Staffordshire, Keele University School of Medicine, Stoke on Trent ST4 7LN, UK.