1. AO Research Institute Davos Davos Switzerland
2. Department of Orthopedics University Medical Center Utrecht Utrecht The Netherlands
3. Department of Orthopedics and Trauma Surgery Medical Centre—Albert‐Ludwigs‐University of Freiburg, Faculty of Medicine, Albert‐Ludwigs‐University of Freiburg Freiburg Germany
4. Department of Orthopaedic Surgery and Traumatology, Inselspital Bern University Hospital, University of Bern Bern Switzerland