1. Department of Orthopaedics, Catharina Hospital, 5623 EJ Eindhoven, Netherlands
2. Research Centre Linnaeus Institute, Spaarne Hospital, 2134 TM Hoofddorp, Netherlands
3. Department of Orthopaedics, VU University Medical Centre, 1081 HZ Amsterdam, Netherlands
4. Department of Orthopaedics, Spaarne Hospital, 2134 TM Hoofddorp, Netherlands