1. Department of Clinical and Experimental Medicine, University of Foggia, 71100 Foggia, Italy
2. Department of Medical Science, Section of Gerontology and Bone Metabolism Diseases, University of Torino, 10126 Torino, Italy
3. Department of Orthopedics, Washington University School of Medicine, St. Louis, MO 63110, USA
4. Department of Basic Medical Sciences, Neurosciences and Sense Organs, Section of Human Anatomy and Histology, University of Bari, 70124 Bari, Italy