Spinal stenosis occurs when the spinal canal narrows, irritating the spinal cord and nerve roots of the spine. The spinal cord consists of millions of nerve fibers that connect the brain with the rest of the body. The nerve roots are the nerve fibers that branch off along the spinal cord and connect to specific parts of the body. If any of these structures are irritated or "pinched," the result can be low back pain and pain in the legs, the most common sites of problems. In rare cases, spinal stenosis can affect the neck area and be crippling if not treated.
What causes spinal stenosis?
The spinal canal is formed by bony rings attached to the vertebrae. The bodys 24 vertebrae are essentially stacked on top of each other, and the bony rings form a hollow tube to hold and protect the spinal cord.
A narrowing of this tube, the spinal canal, is usually caused by an excessive growth of bone and/or tissue, reducing the size of the opening. The result is a "pinching" or irritation of the spinal column and/or the nerve roots of the spine.
There are several reasons that may lead to the spinal canal narrowing, including:
- Age-related degeneration: Age-related degeneration, or wear and tear of the spine, is the most common reason for spinal stenosis. Age can cause thickened ligaments, bone spurs, enlargement of the joints that allow the spine to twist and bend, and bulging disc problems. Any of these conditions can narrow the spinal canal.
- Certain diseases and conditions: One of the bone-related diseases that can cause narrowing of the spinal column is osteoarthritis of the spine. In this case, the joint cartilage of the spine is worn away and bony growths, or spurs, occur. Pagets disease and fluorosis are two bone diseases that may soften the spinal bones or cause calcium deposits to form. Infections and tumors may also put pressure on the spinal column.
- Heredity: Sometimes the spinal column is smaller than usual at birth and may cause difficulties, even for a younger person.
- Trauma: A spinal injury or previous spinal surgery may cause swelling that puts pressure on the spinal nerves.
What are the symptoms of spinal stenosis?
Symptoms vary greatly, depending upon the position of or severity of the narrowing. The most common symptoms include:
- Pain with walking or prolonged standing.
- A feeling of heaviness, weakness or tiredness in the legs.
- Numbness or tingling in the legs.
Frequently the symptoms of spinal stenosis disappear with rest or when sitting down. Even leaning or bending forward may relieve pressure on the nerves.
How is spinal stenosis treated?
Treatment is based on the severity of symptoms. Most cases of spinal stenosis are treated conservatively to control or lessen the symptoms.
Spinal stenosis is problem that generally responds well to non-surgical care. Treatments may include the following:
- Medication: Over-the-counter pain relievers and anti-inflammatory medications, muscle relaxants, and some narcotic medications may be prescribed, depending upon the level of pain.
- Physical therapy: Patients will often be taught exercises to strengthen the back and abdominal muscles and maintain flexibility of the spine. A patient also learns correct posture and body movements to reduce pressure on the spine.
- Rest and slowed follow-on activity: In some cases, decreased activity or rest is prescribed followed by the gradual resumption of activities and eventually increased exercise.
- Weight loss: In some cases, losing weight relieves stress on the spine.
- Epidural Steroid Injection (ESI): This injection is used to help reduce severe pain and swelling in the spinal canal if other conservative treatments do not provide relief. The shots are given on an outpatient basis.
Although the majority of spinal stenosis problems do not require surgical intervention, sometimes the pain and resulting disability are so severe that back surgery is the only option. Surgery removes or adjusts damaged parts of the spine to restore spinal alignment and strength, and to alleviate pressure on the spinal column and nerves.
The traditional way of surgically treating spinal stenosis is to perform a decompressive laminectomy of the lumbar spine to make the tube of the spinal canal larger. In this procedure, an incision is made over the affected area of the spine. The surgeon then removes a section of bone, called the lamina, from the back of the spine. The surgeon may also have to remove a portion of the facet joints, the joints of the spine that connect vertebrae to each other and give the spine its flexibility. If the stability of the spine is affected by the removal of any of the spines components, the surgeon may include spinal fusion as part of the procedure. The surgeon then closes the incision.
The pain that occurs after surgery, as after any surgery, can be relieved with pain medication. Patients sometimes feel continued pain after the surgery. This pain normally lessens as the spine heals.
Most patients get up and walk the day after surgery under the guidance of medical personnel. The average hospital stay can be up to three days, depending upon individual circumstances.
A patient will be given specific instructions before leaving the hospital about wound care and which activities to avoid while the body heals from the surgery.