Intervertebral discs are natural shock absorbers between the
boney vertebrae. Discs have two main components, an outer fibro-
elastic containment rim and an inner soft gelatinous core. When
axial loading pressure occurs along the spinal column, the
central gelatinous core of the disc squeezes outward against the
fibro-elastic containment rim of the disc. The elastic recoil of
the containment wall pushes the gelatinous core back into
position, reestablishing the height and shape of the disc. As a
person ages, natural daily activity causes repeated loading of
the disc. Tiny tears may develop in the fibers of the fibro-
elastic outer containment wall. This causes some loss of the
disc’s outer containment wall elasticity or recoil. The outer
disc containment wall can no longer push the central core
material back into shape as effectively. The outer containment
wall sags, and is said to bulge or collapse. If a tear in the
disc’s containment wall is sufficiently large, the central core
material may extrude into the a