1. Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA
2. Department of Orthopaedic Surgery, General Hospital of Levadia, 32100 Levadia, Greece
3. 1st Department of Orthopedic Surgery, Athens University Medical School, Attikon University General Hospital, Chaidari, 12462 Athens, Greece