Evaluating facet joint pain

by Nathan Wei, MD, FACP, FACR

Nathan Wei is a nationally known board-certified rheumatologist and author of the Second Opinion Arthritis Treatment Kit. It's available exclusively at this website... not available in stores.

Click here: Second Opinion Arthritis Treatment Kit

Located on the back of the spinal column, the facet joints link the vertebra together. Articular cartilage covers the surfaces where the joints meet. Just as with other joints in the body that are covered with articular cartilage, the lumbar facet joints can be affected by arthritis.

The spine is made up of 24 bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column.

The back portion of the spinal column forms a bony ring. When the vertebrae are stacked on top of each other, these bony rings create a hollow tube. This tube, the spinal canal, surrounds the spinal cord as it passes down through the spine from the brain.

There are two facet joints between each pair of vertebrae, one on each side of the spine. The alignment of the facet joints of the lumbar spine allows freedom of movement as a person bends forward and backward.

The surfaces of the facet joints are covered by articular cartilage. Articular cartilage is a smooth, rubbery material that covers the ends of most joints. It allows the bone ends to move against each other smoothly, without friction.

Normally, the facet joints fit together snugly and glide smoothly, without pressure. With the development of arthritis, cartilage on the joint surfaces wears away.

Each segment in the spine has three main points of movement, the intervertebral disc in front and the two facet joints in the back. Injury or problems in any one of these structures affects the other two. As a disc thins with aging and from wear and tear, the space between two vertebrae shrinks. This leads to a situation where the facet joints begin to narrow as well.

The body responds to this extra pressure on the facet joints by developing bone spurs. At the same time the articular cartilage wears away and the bone underneath is uncovered. The joint becomes inflamed, swollen, and painful. This is osteoarthritis.

Facet joint arthritis develops slowly over a long period of time. However, rapid movements, heavy twisting, or backward motions in the low back can injure a facet joint, leading to immediate symptoms.

Pain from facet joint arthritis is usually worse after resting or sleeping. Also, bending the trunk sideways or backward usually reproduces pain on the same side as the arthritic facet joint.

Pain may be felt in the center of the low back and can spread into one or both buttocks. Sometimes the pain radiates into the thighs, but it rarely goes below the knee. Numbness and tingling, the symptoms of nerve compression, are usually not present because facet arthritis generally causes mechanical pain which is pain that comes from abnormal movement in the spine.

Symptoms of nerve compression can sometimes occur in addition to the pain from facet arthritis. Bone spurs may form in the opening where the nerve root leaves the spinal canal. This opening is called the neural foramen. If the spurs rub against the nerve root, the nerve can become inflamed and irritated. This nerve irritation can cause symptoms where the nerve travels. These symptoms include numbness, tingling, abnormal reflexes, and muscle weakness.

Diagnosis

A diagnosis starts with a complete history and physical examination. The physician will ask questions about symptoms and how the problem affects activities of daily living. This will include questions about where the pain starts, where it goes, and if there is numbness or weakness in the legs. The doctor will also want to know what positions or activities make the symptoms worse or better.

Then the doctor performs a physical exam to determine which back movements cause pain or other symptoms.

When more information is needed, the doctor will order magnetic resonance imaging (MRI). This test gives a clear picture of the facet joints to see whether they are enlarged or swollen.

A computed tomography (CT) scan may be ordered. This is a detailed X-ray that lets the doctor see slices of bone tissue. The image can show whether the surface of the joint has eroded and whether bone spurs have developed.

A diagnostic injection may be used to locate the source of pain. The doctor uses a needle to inject a local anesthetic into the joint. He or she will do this using a fluoroscope which is a special real-time X-ray that allows the doctor to watch the spine and the needle. Once the doctor is sure the needle is in the right place, the medicine is injected. The results from the injection help the doctor make the diagnosis. If pain goes away, it helps confirm the source of pain.

Treatment

Facet joint arthritis is mainly treated nonsurgically. Doctors may prescribe a short period of rest, one to two days at most, to reduce inflammation and pain. Patients may find added relief by curling up to sleep on a firm mattress or by lying back with their knees bent and supported. These positions take pressure off the facet joints.

The doctor may prescribe anti-inflammatory medications. Muscle relaxants are occasionally used to reduce muscle spasm.

Patients may be referred to a physical therapist. By evaluating a patient's condition, the therapist can assign positions and exercises to ease symptoms. The therapist may recommend traction. Traction is a common treatment for this condition. It gently stretches the low back and takes pressure off the facet joints. The therapist may also prescribe strengthening and aerobic exercises. Strengthening exercises focus on improving the strength and control of the back and abdominal muscles. Aerobic exercises are used to improve heart and lung health and increase endurance in the spinal muscles. Stationary biking offers a good aerobic treatment and keeps the spine bent slightly forward, a position that gives relief for many patients with lumbar facet joint arthritis.

Spinal manipulation can sometimes provide short-term relief of pain from facet arthritis. Spinal manipulation stretches the tissues surrounding the facet joint and helps reset the sensitivity of the spinal nerves and muscles. Patients are shown how to improve strength and coordination in the abdominal and low back muscles. Therapists can also evaluate their patients' workstations or the way they use they use their bodies when they do their activities.

Patients who still have pain after trying various treatments may require injections into the facet joint or the small nerves that go to the joint. An anesthetic is used to block pain coming from the facet joint. The procedure to inject the medication into the joint is similar to the diagnostic injection described earlier. Steroids are occasionally used along with the anesthetic. This procedure has some good short-term results with few side effects.

People with facet joint arthritis rarely need surgery. However, facet joint arthritis is a primary source of chronic low back pain about 15 percent of the time. After trying other types of treatment, some patients may require surgery. There are several types of surgery for facet joint arthritis. The two primary operations are:

• facet rhizotomy
• posterior lumbar fusion

Rhizotomy is a surgical procedure in which a nerve is purposely cut. Facet rhizotomy is a procedure where the small nerves that supply the facet joint are destroyed.

Posterior lumbar fusion is a surgical procedure where two or more vertebrae are joined together. This keeps the bones and painful facet joints from moving.

The surgeon lays a graft of bone on the back of the spine. Many surgeons will also use metal plates and screws to prevent the two vertebrae from moving. This protects the graft so it can heal better and faster.

Clinical evaluation of intra-articular injections for lumbar facet joint pain.

Lumbar facet joint (LFJ) pain is a common cause of low back pain. Thirty-four consecutive patients with a clinical diagnosis of LFJ pain received injections of a local anaesthetic agent and a long-acting corticosteroid agent under radiological control. Nineteen patients experienced immediate lessening of their pain after the injection of local anaesthetic agent, their response supporting the clinical diagnosis. Twelve of these 19 patients experienced clinically significant relief of pain for more than six months. LFJ injection offers improved diagnosis and treatment of LFJ pain. Med J Aust. 1985 Dec 9-23;143(12-13):563-5.