1. Department of Biomedical Sciences, Humanitas University, Pieve Emanuele-Milan;
2. Department of Neurosurgery, IRCCS Humanitas Research Hospital, Rozzano-Milan;
3. Department of Neuroradiology, Humanitas Clinical and Research Center-IRCCS, Rozzano-Milan;
4. Biostatistics Unit, Humanitas Clinical and Research Center, IRCCS, Rozzano-Milan;
5. Department of Neurosurgery, Spine Surgery Unit-NCH4, Fondazione IRCCS Istituto Nazionale Neurologico "Carlo Besta," Milan, Italy; and
6. Spine Center, Schulthess Clinic, Zürich, Switzerland