1. Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
2. Harvard Combined Orthopaedic Residency Program, Boston, MA, USA
3. Department of Orthopaedic Surgery, Leiden University Medical Center, Leiden University, Leiden, the Netherlands
4. Department of Orthopaedic Surgery, University Medical Center Utrecht, Utrecht University, Utrect, the Netherlands