Schmorl's nodes. Correlation of X-ray and histological findings in postmortem specimens.

Histological examinations were conducted on specimens of 368 intervertebral discs (T11/12-L5/S1), using X-ray photography and discography. Specimens were obtained from 61 individuals (36 males and 25 females) whose ages ranged from 25 to 85 years. Fifty-four Schmorl's nodes were found in 28 of the patients (19 males and 9 females), and in 43 discs. In the peripheral regions of Schmorl's nodes, where the vertebral bodies were in contact with the node, growth of cartilaginous cells was seen in many cases. Thickened bone trabeculae were also seen in three nodes accompanied by syncytia. These three nodes were detectable by X-ray photography of all discs containing Schmorl's nodes, and 35 were subjected to discography. Among these discs, 10 showed a limited form of shadow and 25 showed a diffuse form, and Schmorl's nodes were detected in 11 that showed a diffuse form of shadow. It was possible to detect Schmorl's nodes when they were contiguous with a degenerated annulus fibrosus adjoining the nuclear cavity. Pathogenetically, the presence of Schmorl's nodes in patients of middle and advanced age is interpreted to be one of the symptoms of age-related changes in the cartilaginous plate.