Department of Trauma and Orthopeadic Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52 20246 Hamburg, Germany.
Department of Trauma Surgery and Orthopeadics, Pediatric Orthopeadics, Agaplesion Diakonieklinikum Rotenburg, Elise-Averdieck-Str. 17, 27356 Rotenburg (Wümme), Germany.