Thirty-eight fresh human intervertebral discs collected during anterior interbody fusion surgery were histochemically and ultrastructurally analyzed for pigments. Macroscopically, five stages of degeneration were classified according to the color, fibrosis, and fragility of the nucleus pulposus of the discs. In order to demonstrate lipofuscin granules, specimens were subjected to special staining procedures, including carbol fuchsin lipofuscin stain, the Schmorl's reaction, and autofluorescence. Lipofuscin granules were distributed from the inner layer of the annulus fibrosus to the nucleus pulposus. Such granules were numerous in cases of slight or severe degeneration, whereas fewer granules were found in cases of moderate degeneration. However, the stage of macroscopic degeneration of the intervertebral disc did not necessarily correlate with the incidence of lipofuscin granules. By ultrastructural observation, the morphological features of the components of the intervertebral disc and the ultrastructure of the lipofuscin granule were clarified. The ultrastructure of the "brown degeneration" disc exhibited markedly increased amorphous electron-dense bodies located among collagen fibrils in the matrix.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.