Scheuermann's juvenile kyphosis. A histologic study.

The case histories and gross and microscopic findings of two adolescent patients with Scheuermann's kyphosis demonstrate that the anterior longitudinal ligament is bowstrung across the apex of the hyphosis. The microscopic findings include markedly irregular end plates and end plate disruption with protrusion of disk material into the vertebral body. The ring apophysis does not show avascular necrosis. The intervertebral disk is interpreted as normal both by routine histology and electron microscopy. It is postulated that Scheuermann's kyphosis may be secondary to vertebral osteoporosis occurring during the juvenile period rather than to an intrinsic abnormality in the intervertebral disk or ring apophysis.