1. AO Research Institute Davos, 7270 Davos, Switzerland
2. Department of Trauma, University Hospital Zurich, 8091 Zurich, Switzerland
3. Harald-Tscherne Laboratory for Orthopedic and Trauma Research, University of Zurich, 8091 Zurich, Switzerland
4. Institute of Metal Science ‘‘Acad. A. Balevski’’, Bulgarian Academy of Sciences, 1574 Sofia, Bulgaria
5. Department of Plastic and Hand Surgery, Inselspital University Hospital Bern, University of Bern, 3012 Bern, Switzerland