1. Spine Unit, Orthopaedic and Trauma Service, Hospital Español de Mendoza, Mendoza, Argentina
2. Department of Oncologic and Degenerative Spine Surgery, Istituto Ortopedico Rizzoli, Bologna, Italy
3. Department of Pathology, Anatomia e Istologia Patologica, Istituto Ortopedico Rizzoli, Bologna, Italy