Lumbar Spinal Stenosis - Overview
Lower Back Pain Caused by Spinal Stenosis
Lumbar Spinal Stenosis: Definition
This refers to a narrowing of the spinal canal. Certain individuals may have a narrow canal from birth, but the majority of individuals develop narrowing with age. With age, wear and tear arthritic spurs build up on the facet joints in the posterior part of the spine. These arthritic spurs then encroach on the spinal canal and pinch the lumbar nerve roots. This condition can be worsened as well by narrowing and degeneration of the disc at that level as the space for exit of the nerve root (called the foramen) is narrowed further by a degenerated disc. Spinal stenosis is most common in the last three levels of the lumbar spine namely L3-L4, L4-L5 and L5-S1. It is diagnosed and confirmed by an MRI or CAT scan/myelogram.
Lumbar Spinal Stenosis
There are various signs and symptoms of spinal stenosis. A common one is referred to as spinal claudication. This refers to pain in the legs, the calves, or the buttocks. This pain is associated with activity. The pain is often relieved by sitting and resting. It will then often times start up again with activity.
A common complaint is that an individual will be able to walk several blocks then develops leg pain, is able to get rid of the leg pain by sitting and resting for five to ten minutes and then, upon trying to walk another several blocks, the pain will return.
The pain may be a radiating pain like a sciatica or it may be a cramping pain. At times, though, the stenosis may be severe enough that the leg pain is constant and unremitting. It may at times be indistinguishable from the kind of pain that occurs with a herniated disc.
Spinal stenosis will rarely cause paralysis. The condition will tend to gradually worsen with time and cause increasing pain, however.
Spinal stenosis is uncommon in younger people. It usually occurs at age 50 or older. Leg pains from spinal pathology are more common from herniated discs in people under 50. Over 50, it is more common that spinal stenosis will be the problem.
In addition to developmental degenerative spinal stenosis, entrapped nerve roots may be caused by spondylolisthesis or scoliosis.
Patients with congenital spinal stenosis (such as achondroplastic dwarfs) may develop symptomatic stenosis as early as age 15 or 20.
Spinal stenosis can be relieved by removing the overgrown portions of the facet joints posteriorly. At times only parts of the facet joint have to be removed. In more severe cases, most of the facet joints will have to be removed in order to adequately decompress the nerve roots.
Whether or not a fusion has to be performed at the same time as a decompression is dependent upon many factors, including the stability of the spine, the age of the patient, and the amount of bone being removed. The reason for doing the fusion after the decompression is so that instability does not develop and forward slippage or spondylolisthesis does not occur after a decompression.
There is a fair amount of discomfort for about 2 days after the surgery to address lumbar spinal stenosis. On the first post-operative day, the individual can sit and dangle off the side of the bed as well as stand. Over the next couple of days he/she is able to ambulate fairly comfortably and is able to walk up and down stairs without too much trouble. Average hospital stay after a spinal stenosis decompression is approximately 3 days.
Recovery will be quicker if a fusion is not performed simultaneously. If a fusion is performed, then this adds 2-3 days on to the hospital stay and the recovery.
Generally within 3 to 4 weeks after the surgery, the patient should feel good enough that he/she can go back to a desk job. The results with this kind of surgery are quite good. On the order of 80-90% of patients have relief of their pain after the surgery.
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