1. Department of Orthopaedic Surgery, University of Regensburg, Bad Abbach, Germany
2. Biomechanics and Tissue Engineering Laboratory, The Ohio State University, Columbus, OH, USA
3. Clinical Research Unit 208, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Germany
4. Department of Orthopaedic Surgery, University of Aachen, Aachen, Germany
5. Department of Experimental Orthopaedics, University of Regensburg, ZMB/Biopark, Regensburg, Germany