1. Department of Orthopedics and Trauma Surgery, University Hospital Bonn, 53127 Bonn, Germany
2. Department of Orthopedics, Orthopedic Surgery and Sports Medicine, Augustinian Hospital Cologne, 50678 Cologne, Germany
3. Department of Orthopedics and Trauma Surgery, University Medical Center Mannheim of University Heidelberg, 68167 Mannheim, Germany