1. Department of Orthopaedic and Trauma Surgery, Campus Biomedico University of Rome, Via Alvaro del Portillo, Rome, Italy
2. Department of Orthopaedic Surgery, Catholic University of Rome, Largo Francesco Vito 1, Rome, Italy
3. Centre for Sports and Exercise Medicine, Barts and The London School of Medicine and Dentistry, Mile End Hospital, 275 Bancroft Road, London E1 4DG, England