|
Spinal stenosis is a narrowing of the canal where the spinal cord travels from the skull down to the sacrum. Many age-related changes add up to cause this problem. For example, bone spurs can form around the edge of the opening. The ligaments holding the spine together start to thicken and fill in the space.
Disc degeneration and disc bulging can also reduce the amount of space for the nerve tissues. In all of this, the result is low back pain. Some patients have leg pain as well.
A normal spinal canal is a round, symmetrical or even opening. A trefoil-shaped spinal canal is more triangular. In some cases it may look more like a three-leaf clover instead of a round circle.
The shape occurs as a result of how the vertebral bones are shaped and positioned. In particular the position of the facet (spinal) joints and lamina create this shape. The lamina is the part of the vertebral bone that forms an arch around the spinal canal.
Most often this trefoil-shape is only present in the lower lumbar spine around L3 to L5. This condition does put a person at increased risk of developing spinal stenosis. Degenerative changes over time at the joint create or increase the trefoil-shape.
This normal anatomic variation may or may not be hereditary. The only way to know if you have this effect is with imaging studies such as an MRI.
|
