1. Avaton Surgical Group, Genolier Spine Care Center, Clinique de Genolier, Genolier, Switzerland;
2. Department of Radiodiagnostic and Interventional Radiology, Lausanne University Hospital, Lausanne, Switzerland;
3. Department of Orthopedics, University Hospital, Umëa, Sweden;
4. Neurosurgical Service, Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland; and
5. Centre Leenaards de la Memoire, Lausanne University Hospital, Lausanne, Switzerland