Degenerative disease of the lumbar vertebrae begins at the level of the intervertebral discs. They are degenerative phenomena of the disc that appear from 30 to 40 years of age with the dehydration of the disc gelatinous nucleus. It is an injury related to various circumstances and personal factors such as: heredity, the length of the spine, the state of the musculature, overweight, overloads, bad positions or undue efforts.
When the disc degenerates and dehydrates, cracks or fragmentation may occur inside it. Likewise, its height decreases -which we call impingement- and a dysfunction with abnormal vertebral mobility is established. As the disc nucleus degenerates, more tension is transferred to the annulus surrounding the disc and this can lead to disc rupture. If a rupture of the annulus occurs, the disc nucleus may be displaced, which is what we call lumbar disc herniation.
Disc degeneration without herniation
On the other hand, if there is no herniation, disc degeneration need not be responsible for painful conditions. With the passage of time, practically all individuals have disc alterations, but this does not necessarily constitute a disease. However, a degenerated disc can lead to an increase in the amplitude of its movements, and this does cause an overload of the posterior intervertebral joints, which in turn can cause vertebral instability. Likewise, these joints may become hypertrophied as abnormal bone forms around them, thus causing a narrowing of the channels through which the nerves pass, or stenosis.
Sciatica
Sciatica is a picture of low back pain that radiates to the lower extremities following the path of the sciatic nerves. The pain begins in the lumbar region and usually travels through the buttock, the posterior aspect of the thigh and the posterior and external aspect of the leg and foot. Sciatica may be due to spinal stenosis or to a herniated disc, which contacts the nerves. In any case, compressed sciatic nerves cause pain in the lower extremities, in the territory innervated by them.