Intervertebral Disc DegenerationIntervertebral DiscIntervertebral Disc DisplacementSpinal DiseasesLumbar VertebraeFibrocartilageSpinal OsteophytosisAggrecansDiskectomyMagnetic Resonance ImagingCollagen Type IIProteoglycansRadiculopathyDiskectomy, PercutaneousForaminotomyCervical VertebraeThoracic VertebraeDisease Models, AnimalLaminectomyLow Back PainSciaticaSpineLumbosacral RegionCollagen Type IXWeight-BearingSpinal CanalDecompression, SurgicalCompressive StrengthIntervertebral Disc ChemolysisSpinal FusionCells, CulturedMyelographyNotochordSpondylolisthesisSacrumRetinal DegenerationMacular DegenerationMicrosurgeryBiomechanical PhenomenaNerve DegenerationSpinal Nerve RootsSpinal StenosisScoliosisChymopapainLordosisDiscitisCadaverBack PainGlycosaminoglycansExtracellular Matrix Proteins