Causes of Lumbar Spinal Stenosis

While lumbar spinal stenosis can be present at birth (congenital lumbar spinal stenosis), the causes are more commonly associated with wear and tear that occurs on the bones of the spine over time (degenerative lumbar spinal stenosis).

Degenerative Lumbar Spinal Stenosis

Degenerative, or age-related, lumbar spinal stenosis typically develops after age 50, as part of the normal aging process. It's common for the symptoms to develop gradually, over several years.

Causes of Degenerative Lumbar Spinal Stenosis

Changes related to wear and tear that cause intrusion into the spinal canal space include the following:

• Bone spurs—As cartilage deteriorates between the joints of the back, small bone growths, called bone spurs, or osteophytes, can develop. Bone spurs sometimes develop due to arthritis in the spine.
• Herniated discs—As the discs in the back deteriorate they can herniate, meaning the disc swells, bulges, or ruptures. When this occurs some of the disc material can protrude into the spinal canal. A herniated disc, while painful, doesn’t always cause lumbar spinal stenosis.
• Changes to ligaments—Changes can occur, especially to the ligamentum flavum, the ligament that runs along the inside of the spinal canal. This ligament can become thickened, taking up more space in the spinal canal. Or, as deteriorating discs lose some of their height, this ligament can buckle.
• Enlarged facet joints— Enlargement of the facet joints in the spine can also cause narrowing of the spinal canal.
• Spondylolisthesis—Refers to the forward slippage of one vertebra over another in the spine. This can cause narrowing of the spinal canal and result in pinching of the nerves. Learn more about spondylolisthesis.

Other Causes of Lumbar Spinal Stenosis

• Back injuries—Can both cause spinal stenosis or can worsen already existing low-level symptoms.
• Tumor growth—Can narrow the spinal canal, but the occurrence of spinal tumors is rare.

Learn more:

• Diagnosis of Lumbar Spinal Stenosis
• Treatment Options for Lumbar Spinal Stenosis