[A clinicopathological study of cervical intervertebral discs--Part 1: On histopathological findings].

In order to examine the aging process of the cervical intervertebral discs, a histopathological study was performed on 158 cervical discs obtained at autopsy from 37 individuals ranging in age from 3 months to 87 years. In the nucleus pulposus, degenerative changes consisting of myxomatous and slightly hyalinized degeneration were already seen in the specimens obtained from subjects in the third decade of life. Degenerative changes of the annulus fibrosus, however, tended to develop from the fourth decade of life, with myxomatous degeneration mainly in the anterior and hyalinized degeneration in the posterior annulus. The horizontal fissure of the annulus extending to its outer portion was seen more frequently in the posterior portion. In the cartilaginous plate of the vertebral body, fissure formation and degeneration became evident in the fifth decade of life. In contrast to the disc, repairing processes were observed in the cartilaginous plate. Spur formation at the corner of the vertebral body may be due to the degeneration of the outer layer of the disc leading to enchondral ossification.