Comparing contribution of bony and cartilaginous endplate changes to intervertebral disc degeneration.

Objective: To compare the degenerative features of cartilaginous endplate with bony endplate in association with intervertebral degeneration in local population at radiographic, macroscopic and microscopic level in human motion segments. Methods: This cross-sectional descriptive study examined 59 lumbar spine motion segments from adult male cadavers at the Department of Anatomy, University of Health Sciences, Lahore, between May and September, 2022. Radiographic assessment observed bony endplate (BEP) for the presence of sclerosis & osteophytes and degeneration scores from 1-8 were assigned. Macroscopic assessment was done to evaluate BEP, cartilaginous endplate (CEP) and IVD, and scores ranged from 1to 28 for BEP, 1-4 for CEP and 1-64 for IVD were assigned. Microscopic assessment revealed degeneration scores of CEP ranged from 1-42 and 1-30 for IVD. Segments with BEP defects were also identified on radiographs & macroscopy. Results: Significant correlations were observed between the total degeneration scores of BEP with IVD and CEP scores (r=0.88 and r=0.909, respectively, p<0.001). Similarly, the total degeneration scores of the CEP is also significantly correlated with total IVD (r=0.86, p<0.001). Additionally, the samples with BEP defects were having higher IVD degeneration scores (p<0.001). Conclusion: This study, for the first time identifies that there exists a critical association of bony and cartilaginous endplate with intervertebral disc degeneration individually in the same tissue sections using multi-dimension assessment methods. Degeneration in any of the components of VEP is consonantly associated with IVD degeneration. The BEP & CEP, though, they are unique structures but are interlinked with each other structurally and functionally.