1. Orthopaedic and Traumatology Department, Campus Bio-Medical University, Rome, Italy.
2. University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
3. Department of Surgery, Division of Orthopaedic Surgery, Southern Illinois University School of Medicine, Springfield, Illinois, USA.
4. James R. Urbaniak Sports Sciences Institute, Division of Sports Medicine, Duke University Medical Center, Durham, North Carolina, USA.