1. IRCCS Galeazzi Orthopaedic Institute, Milan Private Hospital “San Camillo”, Forte dei Marmi, Lucca - Italy
2. Orthopaedic Unit of Arthroplasty, Istituto Clinico Humanitas, Milan - Italy
3. Department of Orthopaedics and Trauma, University of Pavia, Pavia - Italy
4. Department of Orthopaedics and Trauma, Bristol University, Bristol - UK
5. Department of Orthopaedics and Trauma, University of Milan, Milan - Italy