As a nerve root leaves the canal through a side hole called the lateral foramen, a disc herniation, bone spur, cartilage fragment, scar tissue or any other unnatural growth or obstruction can press on the nerve root. This type of stenosis may is called lateral spinal stenosis. This is by far the most common form of spinal stenosis. Over 72% of cases of foraminal stenosis occur at the lowest lumbar level, usually trapping the emerging nerve root of the sciatic nerve. Neural foraminal narrowing is a common result of disc degeneration. The process of disc degeneration or bulging can cause the foraminal canal to narrow. Once the foraminal opening reaches a point of compressing the nerves inside the spinal column, pain, numbness, tingling, and muscle weakness often occur. Other possible causes of neural foraminal narrowing include rheumatoid arthritis, osteoarthritis, chronic meningitis, tumors, and neurofibromas.

 

Lumbar spinal stenosis is a narrowing of the spinal canal which compresses the nerves traveling through the lower back into the legs. While it may affect younger patients due to developmental causes, it is more often a degenerative condition that affects adults. Lumbar spinal stenosis is a result of the degeneration of the facet joints and the intervertebral discs in the spine. The discs may become less spongy with age, resulting in reduced disc height and bulging of the hardened disc into the spinal canal. At the same time, bones spurs, which are called osteophytes, may develop to help reduce the stress on the weakened disc. These bone spurs usually grow into the spinbal canal. The facet joints also enlarge as they become arthritic, which contributes to a decrease in the space allowed for the nerve roots. Currently, it is estimated that about 400,000 Americans may be suffering from the symptoms of lumbar spinal stenosis.

 

When present, symptoms may include:Pain, weakness, or numbness in the legs, calves, or buttocksPain radiating into one or both thighs and legs, similar to sciaticaIn rare cases, loss of motor functioning of the legsIn rare cases, loss of normal bowel or bladder function

Degenerative spondylolisthesis is a condition associated with lumbar spinal stenosis.

 

Degenerative spondylolisthesis (slippage of one vertebra over another) is caused by osteoarthritis of the facet joints. Most commonly, it involves the L4 slipping over the L5 vertebra. It is usually treated with the same conservative and surgical methods as lumbar spinal stenosis.

 

Degenerative scoliosis (curvature of the spine) occurs most frequently in the lower back and more commonly affects older people. Back pain associated with degenerative scoliosis usually begins gradually, and is linked with activity. The curvature of the spine in this form of scoliosis is often relatively minor, so surgery is required when conservative methods fail to alleviate pain associated with the condition.