Lumbosacral RegionSacrumSpinal CordSpinal Cord InjuriesLumbosacral PlexusSpinal Nerve RootsSpinal Cord DiseasesSpinal Cord CompressionSpinal Cord NeoplasmsSciatic NerveSpinal NervesLumbar VertebraeInjections, SpinalMotor NeuronsSpinal Cord IschemiaPeripheral NervesNerve RegenerationCauda EquinaNerve FibersSpinal CanalSpinal DiseasesRadiculopathySpinal NeoplasmsParaplegiaOptic NerveTibial NerveSpinal FusionAxonsNerve Compression Syndromes