Lumbosacral RegionSacrumSpinal CordSpinal Cord InjuriesLumbosacral PlexusSpinal Cord DiseasesSpinal Nerve RootsSpinal Cord NeoplasmsSpinal Cord CompressionLumbar VertebraeSpinal Cord IschemiaInjections, SpinalMotor NeuronsCauda EquinaSpinal NervesSpinal CanalSpinal NeoplasmsSpinal DiseasesParaplegiaRadiculopathySpinal Fusion