Spinal Cord DiseasesIntervertebral Disc DegenerationSpinal CordIntervertebral DiscSpinal Cord InjuriesIntervertebral Disc DisplacementCervical VertebraeLumbar VertebraeSpinal FusionMuscular Atrophy, SpinalSpinal DiseasesDiskectomySMN Complex ProteinsTotal Disc ReplacementSpondylosisFibrocartilageProsthesis ImplantationProstheses and ImplantsSurvival of Motor Neuron 1 ProteinSpinal Cord CompressionInternal FixatorsSpinal Cord NeoplasmsIridoid GlycosidesSpondylolisthesisLow Back PainMotor NeuronsArthroplastyQuadriplegiaSacrumSpinal StenosisMagnetic Resonance ImagingSpinal CanalRibonucleoproteins, Small NuclearLaminectomyBack PainTreatment OutcomeMyelitisPhrenic NerveAggrecansPain MeasurementBone ScrewsAnterior Horn CellsSpinal Cord IschemiaForelimbMyelography