Imaging of degenerative disk disease

Abstract

Degenerative disk disease (DDD) results in alterations of both the intervertebral disk and vertebral end plates and has three common sequelae: disk herniation, stenosis, and instability. The progressive dehydration of the nucleus pulposus secondary to degradation of proteoglycans and the development of clefts within the anulus fibrosus lead to loss of height of the intervertebral space and bulging of anulus outer fibers. Besides, cartilaginous end plate thinning and focal anular rupture occur, associated with alterations of subchondral bone properties. DDD is usually associated with apophyseal joint osteoarthritis which contributes to central, radicular, and/or foraminal stenosis. Instability secondary to the loss of normal spinal biomechanics may be identified on static or dynamic radiographs and manifest potentially as spondylolisthesis or retrolisthesis.