Intervertebral disc degeneration instigates vertebral endplate remodeling and facet joint pathology in a large animal model

MRI T2 mapping and post-contrast enhanced T1 mapping. Animals were euthanized at 12 weeks post-ChABC injection for end-term structure-function analysis of the disc, vertebral endplate and facet tissues. Intradiscal injection of ChABC yielded a spectrum of disc degeneration independent of ChABC dosage. Increasing severity of disc degeneration correlated with increased vertebral endplate bone density. In levels that did not exhibit severe degeneration or endplate resorptions, we demonstrated a significant correlation between NP T2 values and disc diffusion properties. Early-stage osteoarthritis of the facet joints was observed concomitant with disc degeneration, characterized primarily by alterations in facet cartilage mechanical properties. This work established a large animal model of whole spinal motion segment degeneration, including correlations between trans-endplate diffusion and disc health, which can be utilized to increase the translational relevance of studies evaluating strategies for disc regeneration or repair.