1. Department of Hand Surgery, Orthopaedic Department, Children’s University Hospital, Steinwiesstrasse 75, CH-8032 Zurich, Switzerland.
2. Department of Surgery, Kantonsspital Bruderholz, CH, 4101 Bruderholz, Switzerland.
3. Balgrist Orthopaedic University Hospital, Zurich Forchstrasse 340, CH 8008, Zurich, Switzerland.