1. Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
2. Department of Electron Microscopy, Center of Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
3. Center for Musculoskeletal Surgery, Charité University Medicine, 10117 Berlin, Germany
4. Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
5. International Center for Lysosomal Diseases, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
6. Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy