1. Department of Emergency Medicine, University Hospital Jena, Friedrich Schiller University, Jena, Thüringen, Germany
2. Center of Orthopaedics and Traumatology, University Hospital Brandenburg an der Havel, Brandenburg Medical School Theodor Fontane, Germany
3. Department of Statistics, Faculty of Medicine, University of Salamanca, Salamanca, Spain
4. Department of Surgical Propaedeutics, Faculty of Medicine, Medical University of Pleven, Pleven, Bulgaria