Lumbar Spinal Stenosis
What does spinal stenosis mean?
Spinal Stenosis refers to narrowing (stenosis) of the spinal canal. The spine is made of multiple vertebrae (bone) which are stacked on one another. Between these vertebrae are flexible discs. This structure allows our spine to move in various directions. In the center of this structure is a canal for nerves from the brain to travel down to the rest of the body. As we age, our discs and bones start to wear away (arthritis). This occurs in everyone, and the rate at which this happens can vary depending on many factors. As our discs and bones wear away the channel for our nerves and spinal cord narrows, and eventually the spinal cord or spinal nerves can become pinched and put under significant pressure. This compression will cause specific symptoms depending on the location where it occurs. Spinal stenosis most commonly affects the cervical (neck) and lumbar (lower back) regions of the spine.
What does spinal stenosis in the lower back cause?
Degenerative lumbar spinal stenosis is a common cause of lower back pain and leg pain that is most frequently encountered in individuals older than 50. The classic symptoms include progressive back, buttock or leg pain, and lower extremity numbness or weakness which worsens with standing and walking. While not as serious as cervical spinal stenosis (which affects the neck) lumbar spinal stenosis is still a great burden to those who suffer from it. Since the pain can prevent one from performing activities of daily living, it can seriously inhibit independence. Spinal stenosis is position dependent meaning that individuals will usually are more symptomatic with standing and notice relief with sitting or lying down. Why does this happen? With upright positioning the diameter of the spinal canal is narrowed, resulting in compression of the spinal cord and nerves. These symptoms are typically relieved by changing to a seated or forward flexed position (like when leaning on a counter or shopping cart) since this forward flexed position increases the diameter of the spinal canal.
Stenosis is a multifactorial degenerative process. It reaches a critical impact when the spinal canal narrows due to any combination of disc degeneration, spondylolisthesis (forward slippage of one vertebra over the one below it), thickening of the para-spinal ligaments, or facet joint arthritis. The condition can affect an individual’s ability to perform daily activities, thereby lowering their quality of life and ultimately threatening their independence.
How do we treat spinal stenosis?
Surgery should not be the first resort! Most patients experience relief from much less invasive treatment such as medications, activity modification, physical therapy and epidural steroid injections. These are the mainstay of conservative care for spinal stenosis. Spinal stenosis isn’t a life-threatening condition and, accordingly, it is not unreasonable to consider simply having the patient spend more time in a seated position. Studies show that in the majority of patients, the symptoms are likely to remain unchanged over time and that fewer than 20% of people will actually get worse.
When is Surgery Required for Spinal Stenosis?
Spinal stenosis is a mechanical problem, so patients might fail to achieve sustained relief with conservative therapy. These treatment options do not alter the anatomical/mechanical pathology that causes the compression. This is why surgery cannot be ruled out entirely. Patients with persistent symptoms who fail to respond to conservative management are generally offered spinal stenosis surgery, though there are many surgical options. The goal of surgery is to alleviate the pressure on the spinal cord and nerves while preserving the stability of the spine.
The conventional surgical treatment for spinal stenosis is a lumbar laminectomy where the bone is removed from the posterior portion of the spinal canal in order to decompress the spinal cord and exiting nerve roots. If the symptoms are strictly one-sided, a unilateral hemilaminectomy or foraminotomy may be performed to limit the amount of bone that is removed. A spinal fusion may be recommended along with the decompression if your surgeon feels that removing the bone that is contributing to the stenosis will result in destabilization of that portion of the spinal column.