The structure of the cartilaginous end-plates in elder people

Low back pain is the leading cause of work-related disability. Degeneration of the intervertebral disc (IVD), the boundaries of which with age-related changes remain obscure, is considered to be its most important cause. The cartilaginous end-plate (CEP) is the anatomic boundary of the IVD. Since the latter is avascular in adults, the CEP is supposed to play a key role in the metabolism of the IVD. Consequently, it has been postulated that the decrease in permeability of the CEP is the main cause of degeneration of the disc. However, the permeability depends at least partially on the morphologic state of the CEP. Little is known about the age-related changes of the CEP compared to those of the IVD. The objectives of the study were to examine the CEP at different ages, to classify the age-related changes in both the CEP and IVD, and to compare them. The intervertebral discs of the five levels of ten human lumbar spines were collected from cadavers aged from 47 to 78 years, and studied macroscopically and microscopically. Morphologic features of the CEP (thickness, IVD/CEP length ratio, degree of calcification, marrow contacts, CEP-VB and CEP-IVD separations) were measured. Morphologic grades were assigned for both the CEP and the IVD. No significant differences were found with regard to these features in the different age-groups. On the other hand, no significant correlation was found between the morphologic grade of the CEP and that of the IVD, suggesting that the importance of the CEP in disc degeneration may be debatable.