1. Orthopedic Surgery, Ruhr-University Bochum, Germany
2. Surgery, Uniwersytet Jagiellonski Collegium Medicum Wydzial Lekarski, Krakow, Poland
3. Emergency Medicine, Uniwersytet Jagiellonski Collegium Medicum Wydzial Lekarski, Krakow, Poland
4. Pediatric surgery, HELIOS-Klinikum Erfurt, Germany
5. Orthopedic surgery, Rheintor-Klinik, Neuss, Germany
6. Department for medical computer science, biometry and epidemiology, Ruhr-University Bochum, Germany
7. Pediatric surgery, Heinrich-Heine-Universität Düsseldorf Medizinische Fakultät, Düsseldorf, Germany