Facet Joint

Facet Joint

Sometimes the facet joints are the main cause of back pain. In many cases, the facet joints are at least part of what is causing your back pain. When your doctor thinks the facet joints are a major source of your pain, he may use the term "facet joint syndrome". Facet joint degeneration, or osteoarthritis, can be caused by a combination of aging, pressure overload of the facet joints, and injury.

Pressure overload on the facet joints is probably caused by degeneration of the intervertebral disc. As the discs degenerate, they wear down and begin to collapse. This narrows the space between each vertebra. This narrowing of the space between each vertebra affects the way the facet joints line up. When this occurs, it places too much pressure on the articular cartilage surface of the facet joint. The excessive pressure leads to damage of the articular surface and eventually the cartilage begins to wear away.

When facet joint arthritis gets bad enough, the cartilage and fluid that lubricate the facet joints are eventually destroyed as well, leaving bone rubbing on bone. Bone spurs begin to form around the facet joints. When bone spurs develop, they can take up space in the foramen (the opening between vertebrae where nerve roots exit the spine) and press into nerve roots. As the bone spurs begin to grow larger, they can eventually extend into the spinal canal itself. This leads to narrowing of the spinal canal (spinal stenosis).