A degenerative process of the spine characterized radiographically by the presence of vacuum phenomena, disc space narrowing and reactive sclerosis of the vertebral body.
This disorder is due to ageing, which results in dehydration and loss of tissue resiliency in the intervertebral disc, particularly in the nucleus pulposus.
Alterations occur in the nucleus pulposus, anulus fibrosus, and hyaline cartilage endplate. Clefts appear that extend from the nucleus pulposus into the anulus fibrosus.
Linear or circular radiolucent collections termed a vacuum phenomenon, which appear within the intervertebral discs, represent a reliable indicator of disc degeneration and are very rare in the presence of discal infection. Vacuum phenomena are accentuated with extension and may disappear with flexion.
Later in the course of the disorder, intervertebral disc space loss and bone eburnation become evident. Bone sclerosis generally extends to the intervertebral disc and involves adjacent vertebral bodies. The sclerotic areas may contain radiolucent lesions (cartilaginous nodes or Schmorls nodes).
On radiographs the characteristics of disc space loss and reactive sclerosis in this condition are similar to changes accompanying other spinal disorders.
Owing to the relative insensitivity of routine radiography in detecting abnormalities in the very early stages of intervertebral (osteo)chondrosis, MRI imaging has been employed. MR imaging also allows assessment of signal intensity changes in adjacent vertebral bodies in intervertebral (osteo) chondrosis. Three different patterns are encountered, related to the presence of fibrovascular marrow, fat or sclerotic bone.