1. Department of Neurosurgery, La Timone University Hospital, Assitance Publique Hopitaux Marseille, 13005 Marseille, France
2. Spine Unit, La Timone University Hospital, Assitance Publique Hopitaux Marseille, 13005 Marseille, France
3. Department of Orthopedic Surgery, La Timone University Hospital, Assitance Publique Hopitaux Marseille, 13005 Marseille, France