We all know that the more miles you put on your car, the more likely it is to begin having wear and tear problems. Our spines work in the same way. Like a car, the spine has important relationships among its moving parts. The car can be traded for a new one but we must take care of our spine as best we can for many years.
Spinal stenosis, often an end stage of the spine degenerative process, is characterized by leg pain with walking. Pain will go away with rest but you may have to specifically sit down to ease the leg pain. Occasionally the symptoms of spinal stenosis will come on acutely, but most often it generally develops over several years. A person who stands for long periods or walks will worsen the leg pain. Bending forward or sitting will relieve the pain because these positions help to open up the spinal canal, but the symptoms recur if you stand straight again. Numbness and tingling can also affect you while weakness is less common.
What is Spinal Stenosis?
Our lumbar spine (low back) and cervical spine (neck) are comprised of multiple bones separated from each other by cushions (discs) and connected to each other by small joints. Our anatomy allows our spine to protect neurologic structures, absorb stress and weight, and position our body in space. By its nature, as we age, we are more likely to have degenerative changes that eventually can cause symptoms. Spinal Stenosis refers to narrowing of the canal where the nerves travel to reach their ultimate destination (arms or legs).
Our spinal canal is bordered by three important anatomic structures: discs, joints (facet) and ligaments. With time, the discs dehydrate, lose their height and can bulge, which can cause infringement upon the anterior portion of the canal. At the same time, the small facet joints will begin to degenerate and form bone spurs which can narrow the canal from the sides. Lastly, the ligaments (ligamentum flava) that border the posterior portion of the canal can hypertrophy and contribute to overall narrowing of the canal. The overall degenerative process that contributes to spinal stenosis is slow and can take many years to cause enough narrowing to produce symptoms.
Other Spinal Stenosis Symptoms
Typical patient complaints involve a loss of endurance and fatigue associated with their lower extremities. Back pain often is associated with the leg symptoms but is quickly alleviated when the patient sits. Common symptoms that identify stenosis are decreased ability to walk distances, preference for flexed positions (sitting and sleeping in a fetal position) or leaning over a shopping cart. The body prefers a flexed spinal position because the canal is at its widest dimension with bending rather than standing upright.
Diagnosis of Spinal Stenosis
Tests to confirm a diagnosis of spinal stenosis includes a MRI scan or a CT scan with myelogram. These tests will confirm the suspected narrowing and compression of nerve(s). Since spinal stenosis at one or two levels of the spine can affect a single exiting nerve, a combination of imaging and a physical examination by a spinal physician can confirm the diagnosis.
Non-operative treatment refers to attempts to minimize the stenosis symptoms without altering anatomy (surgery). Physical therapy is a mainstay because increased strength & endurance of our trunk and neck muscles increases support of the bony architecture of the spine and minimizes irritation of degenerated anatomic parts. Non-steroidal anti-inflammatory drugs (NSAIDS) contribute to pain relief by decreasing irritation but they do not change the course of the disease process. Lastly, epidural steroid shots can decrease swelling and irritation of pinched nerves to achieve pain relief. Conservative measures work well because often significant relief can be obtained. In essence, these non-operative measures buy time by minimizing symptoms without altering the underlying issue of the aging spine.
Activity modification can be helpful. For endurance exercise, try a stationary bicycle instead of walking since it is helpful to reduce pain by bending forward. Additionally, leaning over a shopping cart or a walker is effective and sitting in a recliner instead of a straight chair can be more comfortable.
The key to deciding whether or not to have surgery is the degree of disabling pain or disability from spinal stenosis. When you can no longer walk as you enjoyed before or care for yourself as you have previously, it may be time to consider what surgery can do for you.
After a minimum of 6-12 weeks of conservative measures, if no significant improvement has been obtained, surgery can be discussed. The Laminectomy procedure involves "decompressing the pinched nerves" by removing the posterior bony portion (lamina) of the narrowed canal. A laminectomy can take from 1 to 3 hours depending on how many levels of the spine are involved. There are minimal restrictions post-operatively. The majority of patients go home the next day with no restrictions.
A decompressive laminectomy quickly relieves leg symptoms. Barring any permanent nerve changes from chronic compression, patients quickly regain lost strength and walking distance with the help of physical therapy. In certain cases, stenosis is associated with spondylolisthesis, or slipped vertebra. This â€œslipâ€ can become worse after a laminectomy at the same level. In cases like this, a spinal fusion during the same operation is added to minimize potential back pain resulting from spine instability.
The risks associated with decompressive surgery are similar to most surgical procedures. The biggest risk is associated with the anesthesia. To reduce this risk, patients undergo a medical clearance by your primary care physician or cardiologist prior to undergoing surgery. Other risks include infection, dural tears (the nerve sack rips leaking spinal fluid, which is repaired during surgery) and developing stenosis at other levels.
Surgery results are generally 70-80% successful at 5 years. This means you will be able to walk increased distances, have improved functionality, less leg pain and less medication use. The main cause for another surgery is if stenosis develops at levels above or below the primary surgical site.
To conclude, spinal stenosis is a chronic degenerative process that develops over many years. Conservative measures are available to control symptoms until one feels his or her quality of life is severely inhibited. At that point, surgery can be considered. Results from decompression are often very rewarding, allowing the person affected by spinal stenosis to return to their favorite activities.