Intervertebral Disc DegenerationIntervertebral DiscOrthopedicsIntervertebral Disc DisplacementSpinal DiseasesLumbar VertebraeFibrocartilageSpinal OsteophytosisAggrecansCollagen Type IIMagnetic Resonance ImagingProteoglycansDisease Models, AnimalSpineDiskectomyCervical VertebraeLumbosacral RegionLow Back PainCollagen Type IXWeight-BearingCompressive StrengthSpinal FusionIntervertebral Disc ChemolysisCells, CulturedNotochordSpondylolisthesisThoracic VertebraeSacrumRetinal DegenerationMacular DegenerationBiomechanical PhenomenaNerve DegenerationSpinal StenosisScoliosisChymopapainResearchLordosisDiscitisBack PainCadaverGlycosaminoglycansLaminectomyExtracellular Matrix Proteins