1. Orthopaedics Unit, Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari “Aldo Moro,” Bari, Italy
2. National Research Council, Institute for the Science and Technology of Ceramic Materials (ISTEC-CNR), Faenza, Ravenna, Italy
3. Department of Orthopedics and Traumatology, Catholic University, Rome, Italy