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 L3-4, L4-5, and L5-S1. It is diagnosed and confirmed by an MRI or CAT scan/myelogram.
Symptomology
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 is uncommon in younger people. It usually occurs at age 40 or older. Leg pains from spinal pathology are more common from herniated discs in people under 40. Over 40, it is more common that spinal stenosis will be the problem. In addition to developmental degenerative spinal stenosis, entrapped nerve roots may be caused as well by spondylolisthesis and scoliosis. It will rarely cause paralysis. The condition will tend to gradually worsen with time and caus time and cause increasing pain, however. Patients with congenital spinal stenosis (such as achondroplast achondroplastic dwarfs) may develop symptomatic stenosis as early as age 15 or 20.
Treatment
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 joint 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.
Postoperative Course
There is a fair amount of discomfort for about 2 weeks after surgery. On the first postoperative 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 comfortable 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 to 3 days on to the hospital stay. Generally within 6 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 90% of patients have relief of their pain after the surgery.