Spinal Cord DiseasesIntervertebral Disc DegenerationIntervertebral DiscSpinal InjuriesIntervertebral Disc DisplacementSpinal Cord InjuriesSpinal CordLumbar VertebraeSpinal FusionMuscular Atrophy, SpinalDiskectomySpinal DiseasesSMN Complex ProteinsTotal Disc ReplacementThoracic VertebraeFibrocartilageProsthesis ImplantationProstheses and ImplantsSurvival of Motor Neuron 1 ProteinInternal FixatorsSpinal FracturesCervical VertebraeIridoid GlycosidesSpondylolisthesisLow Back PainSpondylosisArthroplastySacrumSpinal StenosisRibonucleoproteins, Small NuclearMotor NeuronsBack PainAggrecansMagnetic Resonance ImagingBone ScrewsTreatment Outcome