1 BG Kliniken - Hospital Group of the German Federal Statutory Accident Insurance, Leipziger Platz 1, 10117 Berlin, Germany. Electronic address: dirk.stengel@bg-kliniken.de.
2 Unfallchirurgie und Orthopädie BG Klinikum Unfallkrankenhaus Berlin, Germany.
3 Department of Surgery, McMaster University, Hamilton General Hospital, 237 Barton Street East, Hamilton, ON, L8L 2 × 2, Canada.
4 Academic Department of Trauma and Orthopaedics, School of Medicine, University of Leeds, United Kingdom.