1. AO Research Institute Davos; Clavadelerstrasse 8 7270 Davos Switzerland
2. University Multiprofile Hospital for Active Treatment and Emergency Medicine ‘N. I. Pirogov’; Sofia Bulgaria
3. Department of Trauma, Hand and Reconstructive Surgery; Friedrich Schiller University Jena; Jena Germany
4. Department of Orthopaedic Trauma; University of Aachen Medical Center; Aachen Germany
5. Cantonal Hospital Baselland; Orthopedic and Musculoskeletal Traumatology Clinic; Bruderholz Switzerland
6. University of Basel; Basel Switzerland