Lower Back pain


lower Back pain syndrome

 2 lower Back pain  syndrome

functional unit in anterior portion

FICURE 4. 1. Annular Abers at rest. 2. Effect of elongation. 3. Effect of compression
4. Effect of flexion or extension. 5. Effect of translatory torque.
The nucleus pulposus is a colloidal gel, a mucopolysaccharide that
has a physical-chemical action. In a "young" and in an undamaged disc
the nucleus is 88 percent water. Due to its colloidal chemical nature it
can imbibe external fluids and maintain its intrinsic fluid balance.
Diffusion of solutes occurs via the central portion of the end plates and
through the annulus (Fig. 5). Increased intradiscal pressure probably
also forces fluid through minute foramina in the end plates. When
pressure is released or decreased, fluid returns into the disc by imbibition.
As the nucleus ages, it loses its water-binding capacity. After the

FIGURE 5. Disc nutrition through diffusion. Diffusion of solutes occurs through the
central portion of the end plates and through the annulus. Marrow spaces exist between
circulation and hyaline cartilage and are more numerous in the annulus than in the
nucleus. Glucose and oxygen enter via the end plates. Sulfate to fonn glucosaminogly.
cans enters through the annulus. There is less diffusion into the posterior annulus. (B.V.
= blood vessels.)

FICURE 6. Vertebral segment. As viewed from above, the vertebral segment is divided
into the anterior and posterior segments. The anterior portion is the vertebral body and
the disc structures. The posterior portion consists of the lamina, pedicles, and facets. In
this segment the posterior longitudinal ligament is incomplete, placing it at the lower
lumbar (L5) level.
first two decades the nucleus water content decreases from its early 88
percent because its water-binding capacity has been decreased. In the
aging process there is a decrease in the protein polysaccharide with an
additional loss of osmotic and imbibition properties.
The intervertebral disc has a vascular supply that disappears after the
second decade. By the third decade the disc, now avascular, receives its
nutrition by diffusion of lymph through the vertebral end plates and by
virtue of the physical-chemical imbibitory characteristics of the nucleus
colloidal gel. The ability of an injured disc to regain its elasticity
is bound to be stronger in the young.
Resistance to stress by the vertebral column is further augmented by
the vertebral ligaments. The ligaments run longitudinally along the
vertebral column and by their attachments restrict excessive movement
of the unit in any direction and prevent any significant shearing action.
The ligaments, by their position and attachments, encase the disc and
reinforce the annulus yet do not detract from its physiologic elasticity.
Viewed at the level of the functional unit, the entire disc is enclosed
anteriorly by the anterior longitudinal ligament and posteriorly by the
posterior longitudinal ligament (Fig. 6