1. Ziekenhuis Oost-Limburg, Department of Orthopaedic Surgery and Traumatology, Genk, Belgium
2. Faculty of Rehabilitation Sciences, University of Hasselt, Hasselt, Belgium
3. Department of Orthopaedic Surgery, University Hospital Antwerp, Edegem, Belgium
4. Department of Orthopaedic Surgery, AZ Monica, Antwerp, Belgium
5. Orthopaedic Specialists, Harley Street Specialist Hospital, London, UK