About Lumbar Spinal Stenosis

It’s normal for the spinal canal to change as you age. But some changes, such as narrowing of the canal, can cause pain. If you’re one of the 700,000 people diagnosed with lumbar spinal stenosis each year, take heart. An innovative device from Medtronic may offer relief.


Lumbar spinal stenosis is a condition caused by narrowing of the spinal canal. In medical terms, stenosis refers to a narrowing or stricture of a duct or passageway.


Changes to the size or shape of the spinal canal usually occur as a result of aging. Normally, there is enough space in the openings of the spinal bones to accommodate the nerve fibres branching off the spinal cord, however, when the size of these openings is reduced (due to an overgrowth of bone or adjacent tissue) nerve compression can occur.

The narrowing that occurs with LSS can also affect the spinal cord by encroaching upon the space available in the spinal canal.

Structures adjacent to the spinal column can also be affected:

  • Spinal ligaments can thicken and harden
  • Bones and joints (often affected by osteoarthritis) can enlarge; bone spurs can develop
  • Discs can bulge or collapse
  • Vertebrae may slip out of place


Narrowing of the spinal canal can impinge upon or put pressure on the nerve roots and spinal cord, causing pain and discomfort.

Patients with lumbar spinal stenosis often notice pain in the buttocks or a “pins and needles” sensation in the thigh or leg that occurs when standing (extension) or walking. The discomfort is usually relieved by bending forward (flexion) or with rest. In some cases, patients will complain of back pain, in addition to leg pain and weakness.

Risk Factors

Some degeneration of the spine occurs in everyone as they age, but the severity of symptoms depends on the size of their spinal canal and the degree of encroachment on the nerves. The rate of deterioration varies greatly from person to person and not everyone will feel symptoms.


A diagnosis of lumbar spinal stenosis begins with a complete history and physical examination. You should discuss your symptoms with your doctor, what makes them better or worse, and when the symptoms began. A physical exam can help with determining the severity of the condition and whether or not weakness and/or numbness is present.

Abnormalities in strength and sensation are assessed by a neurological exam and provide objective evidence of chronic nerve root compression caused by lumbar spinal stenosis. Your physician may also order imaging tests such as x-rays, magnetic resonance imaging (MRI), or computerized tomography (CT) scan to confirm the diagnosis.

Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.

Last updated: 22 Sep 2010

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