Lumbosacral RegionSacrumSpinal CordSpinal Cord InjuriesLumbosacral PlexusSpinal Cord DiseasesSpinal Nerve RootsSpinal Cord CompressionSpinal Cord NeoplasmsLumbar VertebraeSpinal Cord IschemiaInjections, SpinalMotor NeuronsCauda EquinaSpinal NervesSpinal CanalSpinal DiseasesSpinal NeoplasmsParaplegiaRadiculopathySpinal Fusion