The cartilage end-plate and intervertebral disc in scoliosis: calcification and other sequelae.

The morphology and composition of the intervertebral disc and also of the cartilage end-plate were studied in patients with idiopathic or congenital scoliosis. The cartilage end-plate was investigated because of its function as an epiphyseal plate in humans and the association between growth and progression of the scoliotic curve. The proteoglycan and water contents were reduced in both structures in specimens from scoliotic patients, particularly toward the concavity of the curve, compared with autopsy material. The distribution of some collagen types differed in tissue from scoliotic patients and autopsy tissue. Calcification of the cartilage end-plate, and sometimes of the adjacent disc, occurred in all but three scoliotic patients, whereas there was minimal calcification in the autopsy specimens. We suggest that, although these changes are probably a secondary response to altered loading in the scoliotic patients, they may be highly significant to the progression of the scoliotic curve.