1. Department of Trauma Surgery, University Medical Center Regensburg, 93053 Regensburg, Germany
2. Department of Psychosomatic Medicine, University Medical Center Regensburg, 93053 Regensburg, Germany
3. Implant Research Center, Drexel University, Philadelphia, PA 19104, USA
4. Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94063, USA
5. Exponent Inc., Menlo Park, CA 94025, USA