Lumbar spinal stenosis is a narrowing of the spinal canal in the lumbar area (low back).
This narrowing is usually caused by degenerative changes (deterioration) in the spine (vertebrae) that occur as part of the natural aging process. As we age, the disks (cushions between the bones of the spine) on our spinal column lose fluid and height. The loss of height results in "disk bulging. The small joints in the back part of the spine develop osteophytes ("spurs"). The ligaments surrounding the spinal column tend to thicken.
In combination, these changes lead to a decrease in the space available to the nerve roots as they travel through and exit the spinal canal. Once the narrowing of the spinal canal gets to a critical point, the blood supply to the nerve roots that supply sensation and motor power to the legs is cut off.
Spinal stenosis tends to run a very gradual course. Symptoms may not worsen for several years and certainly there is nothing life threatening about this condition. It is only when the level of symptoms becomes intolerable in terms of limiting a person's quality of life that surgery should be considered.
Patients usually experience back and/or leg pain. In more severe cases, there may be numbness or weakness as well. Symptoms are typically worse when you stand and/or walk because in this posture, the spinal canal becomes narrower than when you bend forward or sit. Thus, individuals with spinal stenosis find it difficult to stand up straight or walk distances without leg pain. Bending forward or sitting usually relieves their pain.
Diagnosis and Evaluation
Plain X-ray films do not typically show spinal stenosis. Therefore, your doctor will order a magnetic resonance image (MRI) or a myelogram and computerized tomogram (CT) scan. These specific tests accurately show the amount of stenosis. It is important for your physician to order one of these studies to be sure of the diagnosis and properly plan your treatment.
Conservative (non-operative) treatment for spinal stenosis includes pain medication (non-steroidal anti-inflammatories - NSAIDs), physical therapy, and bracing. However, when these methods of treatment fail to control symptoms, surgery may be indicated. Only surgery can actually widen the spinal canal.
The surgery to widen the spinal canal is termed a "decompression". The procedure is performed through an incision on your back. During the procedure, the orthopaedic surgeon removes the laminae (bony arches of the spinal canal), and the ligaments between these arches which may be contributing to the stenosis. Occasionally, a portion of the damaged disk joint itself may need to be removed. If a sufficient amount of tissue is removed, then it may be necessary to perform a fusion operation as well, in order to prevent the occurrence of spinal deformity and pain post-operatively.
Typical hospital stays for a simple decompression surgery usually range from 1 to 3 days. After surgery, you may need to wear a lightweight brace for comfort; however, most patients are not required to wear a brace.
Once discharged from the hospital, patients are able to get out of bed independently and walk without assistance. Some help at home for the first few weeks following surgery is usually necessary. By six to eight weeks after surgery, most patients find that they are about 90 percent back to their full potential.
Overall, this type of surgery is successful in eliminating leg pain and allowing patients to walk further in about 80 to 85 percent of cases. The relief of back pain is less reliable. Most patients, however, do find that their back pain is significantly decreased, if not completely relieved.