1. Department of Pediatric Orthopaedics and Foot and Ankle Surgery, Orthopaedic Hospital Speising, Vienna, Austria
2. Department of Surgery, Krankenhaus Göttlicher Heiland, Vienna, Austria
3. Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
4. Department of Orthopedics, All India Institute of Medical Sciences, Deoghar, India