Spondylosis and lumbar instability: pathologic changes.

The degenerative processes of the lumbar spine generally initiate from the intervertebral disc, at the level of which progressive biochemical and structural changes take place leading to a modification in its physical properties of elasticity and mechanical resistance. Disc lesions cause pathological changes in the vertebral bodies, where osteophytes appear, and in the posterior joints. In more severe forms of the process the severe deformation of joint shape may lead to a condition of spondylolisthesis.