Glossary

Degenerated disc - Changes in a disc characterized by desiccation, fibrosis and cleft formation in the nucleus, fissuring and mucinous degeneration of the anulus, defects and sclerosis of end-plates, and/or osteophytes at the vertebral apophyses.

Degenerative disc disease - A clinical syndrome characterized by manifestations of disc degeneration and symptoms thought to be related to those changes

Delamination: Separation of anular fibers along planes parallel to the periphery of the disc, thought to represent separation of laminated layers of the outer anulus fibrosus.

Desiccated disc - Disc with reduced water content, usually primarily of nuclear tissues.

Disc Degeneration - The loss of the structural and functional integrity of the disc.

Disc space height - The distance between the planes of the end-plates of the vertebrae craniad and caudad to the disc.

Disc space - Space limited, craniad and caudad, by the end-plates of the vertebrae and peripherally by the edges of the vertebral body ring apophyses exclusive of osteophytes. Syn: intervertebral disc space.

Discal level - Level of the vertebral canal between axial planes through the bony end-plates of the vertebrae craniad and caudad to the disc.

Discectomy - Surgical removal of part or all of an intervertebral disc.

Discogenic vertebral sclerosis - Increased bone density and calcification adjacent to the end-plates of the vertebrae craniad and caudad to a degenerated disc, usually a manifestation of intervertebral osteochondrosis.

Displaced disc - A disc in which disc material is beyond the outer edges of the vertebral body ring apophyses (exclusive of osteophytes) of the craniad and caudad vertebrae, or, as in the case of intravertebral herniation, penetrated through the vertebral body end-plate.

Distal - Situated away from the center of the body.

Distraction - Excessive space between fracture fragments or vertebral segments due to interposed tissue or, most often, axial forces.