1. IIa Clinica Ortopedica e Traumatologica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
2. Knee Unit, Orthopaedic Department, Hospital del Trabajador, Santiago, Chile
3. Department of Orthopaedic and Trauma Surgery, Klinik Für Orthopädie und Unfallchirurgie, Malteser Waldkrankenhaus St Marien, Erlangen, Germany
4. Department of Orthopaedic Surgery, University Medicine Rostock, Rostock, Germany