Spinal stenosis is narrowing of the spaces in the spine that cause pressure on the spinal cord and nerves. This condition can involve narrowing of one or more of three spine areas: the canal in the center of the spinal column, the canals at the base of nerves, and the openings between vertebrae (spinal bones).
Spinal stenosis affects both men and women over the age of 50 years. However, it can occur in young people born with a narrow spinal canal, or those who suffer a spinal injury.
The spine is a column of 26 vertebrae that extend in a single line from the skull to the pelvis. These bones are separated by pads of cartilage (intervertebral discs) that are filled with a gel-like substance that cushions the column. Ligaments are elastic bands of tissue that support the spine and hold vertebrae in place. The facet joints are tiny structures along the posterior region of the spine, and they allow for backward spinal motion. Finally, the spinal cord extends from the brain down the vertebral column, and it consists of bundles of spinal nerves.
The normal vertebral canal provides adequate room for the spinal cord. With spinal canal narrowing, there is pressure on the spinal nerves and ligament stretching. This results from degenerative aging, as well as acquired conditions. When surfaces of vertebral bone project out of alignment, they can produce pain. When facet joints thicken, and bone spurs occur, this decreases the neural foramen, which is the space available for nerve roots. Pain occurs from impingement on these nerves.
In a recent study involving more than 3,500 participants, researchers evaluated the prevalence of lumbar spinal stenosis. In the congenital group, stenosis was found in 5% of participants. Acquired spinal stenosis was also diagnosed in 22% of patients, which showed increasing prevalence with age.
The symptoms associated with spinal stenosis include:
Spinal stenosis is diagnosed by:
Kailihmann L, Cole R, Kim DH, et al. (2009). Spinal stenosis prevalence and association with symptoms: the Framingham Study. Spine J, 9(7), 545-550.