What is Facet Joint Disease?
Facet joints occur in pairs at the back of each vertebra. The facet joints link the vertebrae directly above and below to form a working unit that permits movement of the spine. The structure of the facet joint is identical to other joints in the body, such as knees and hips. The bone surfaces of the facet joints are covered with a specialized tissue called articular cartilage. The joint is lined by a membrane called the synovium and enclosed in a fibrous sac called a joint capsule. A thick liquid (synovial fluid) surrounds the joint, allowing the bones to move without friction.
Facet joint syndrome refers to pain that occurs in the facet joints. This syndrome most often affects the lower back and neck. Lumbar facet syndrome might cause referred pain to the buttocks and thigh. Facet syndrome in the neck might cause headaches or shoulder pain.
What are the symptoms of facet joint syndrome?
Symptoms of facet joint syndrome in the lower back include:
- Pain or tenderness in the lower back
- Pain that increases with twisting or arching the body
- Pain that moves to the buttocks or the back of the thighs — This pain is usually a deep, dull ache
- Stiffness or difficulty with certain movements, such as standing up straight or getting up out of a chair
Symptoms of facet joint syndrome in the neck include:
- Neck pain
- Shoulder pain
- Difficulty rotating the head
What causes facet joint syndrome?
There are several possible causes of pain that originates in a facet joint. An injury and/or changes associated with aging might cause the cartilage cushion that covers the bones to wear away, causing pain as the bones of the joint rub together.
In addition, small nerves that branch out from the spinal nerves supply the facet joints. Irritation or pinching of these nerves also can lead to pain. Poor posture, which forces the spine out of alignment, can be a factor in the development of pain from the facet joints. Trauma, inflammation, infection, and disc degeneration are other suggested causes of facet joint pain.
How common is facet joint syndrome?
Facet joint syndrome is more common in the elderly, as changes to the joints associated with aging are present in most people over 50 years of age.
How is facet joint syndrome diagnosed?
Often, a health care provider will suspect facet joint syndrome after an evaluation that includes a complete medical history and physical examination. The health care provider might order an X-ray, computed tomography (CT) scan of the spine, or magnetic resonance imaging (MRI) scan to rule out another disorder — such as a fractured or herniated disc — as the cause of the pain.
A procedure called a facet joint block might be done to determine if the facet joints are the source of the pain. A facet joint block involves injecting a numbing medicine into or very near the nerves that supply the facet joint. Facet joint syndrome is confirmed if there is a significant decrease (50 percent or more) in pain after the joint has been numbed. If the pain is not relieved by the injection, it is unlikely that the facet joint is the source of the pain.