Abnormal Anatomy

The drawings above and below represent the appearance of a herniated or ruptured disc. Both drawings show the disruption of the annulus fibrosus, the outer ring-like portion of an intervertebral disc.

The tissue located in the center of the intervertebral disc, the nucleus pulposus, is partially extruded from the intervertebral disc. The extruded nucleus pulposus material can exert pressure on nerves thus causing pain, numbness, and muscle weakness due to nerve damage.

An abnormal spinal condition known as scoliosis is shown in this drawing. Scoliosis is a lateral (sideways) curvature of the spine.

Spondylolisthesis is an abnormal spinal condition in which one vertebra slips or is displaced over another vertebra. The drawing shows spondylolisthesis as a result of a lumbar vertebra (L5) slipping over the sacrum (S1).
See Spondylolisthesis Animation

This drawing depicts the spinal condition of kyphosis. Kyphosis is an abnormal increase in normal kyphotic (posterior) curvature of the thoracic spine which can result in a noticeable round back deformity.

This drawing represents the spinal condition of lordosis. Lordosis is the abnormal increase in normal lordotic (anterior) curvature of the lumbar spine. This can lead to a noticeable "sway-back" appearance.

This drawing illustrates degenerative and hypertrophic arthritis between the 3rd, 4th, and 5th lumbar vertebrae, as well as the lumbosacral joint (L5-S1 disc space). The degeneration of the intervertebral discs has reduced the height of the discs. There are bone spurs or hypertrophic bone adjacent to the discs and hypertrophic arthritis of the facet joints. This results in reduced range of motion of the spine. Also, the hypertrophic bone and narrowing of the intervertebral foramen can produce nerve root impingement thereby causing back and leg pain, as well as numbness and weakness of leg muscles.

Republishes with permission from Medtronic Sofamor Danek