1. Pelvic Unit, San Luigi Hospital of Orbassano, II Faculty of Medicine and Surgery, University of Turin, Orbassano - Italy
2. Orthopaedic Department, Humanitas Hospital of Rozzano, Rozzano - Italy
3. Orthopaedic Department, Portogruaro Hospital, Portogruaro - Italy
4. Orthopaedic Department, Sacro Cuore Hospital, Negrar - Italy
5. Department of Orthopaedic Surgery, Inselsplital, University of Bern, Bern - Switzerland