1. Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, the Netherlands
2. Clinical Research Unit, Academic Medical Center, Amsterdam, the Netherlands
3. Department of Orthopaedic Surgery, Slotervaart Hospital, Amsterdam, the Netherlands
4. Department of Orthopaedic Surgery, Diaconessenhuis, Leiden, the Netherlands
5. Department of Orthopaedic Surgery, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, the Netherlands