One source of chronic spine pain is the facet joints. Spinal facet joints are true “synovial joints” (like the shoulder and the knee). These joints have a joint capsule lubricated with fluid and richly innervated by a network of pain-sensitive nerve fibers. Facet joints are numerous, with two at each spinal level. These joints are prone to injury, and are one of the major structures damaged in whiplash injuries. They can be associated with disc disease at any one particular spinal level, or be painful by themselves.

Origins of Facet Joint Pain

Facet joints become especially vulnerable when the intervertebral disc is injured. This is true because as the disc degenerates, the volume of the disc is reduced and the disc space tends to flatten out. The disc therefore loses height and the space between the vertebral bodies becomes narrowed. The flattening disc space provides much less support for the facet joints at that particular level, and the joints become subject to increased stress. Facet joint pain is often felt in the spinal area rather than in an arm or leg.

Interventional Treatments

Just as epidural injections are used to treat disc-related pain within the spinal column, facet joint injections are sometimes used to diagnose and treat pain emanating from the facet joints.

Injections of steroids directly into the facet joints may reduce pain and facilitate rehabilitative therapy. If pain recurs after joint injection, the small sensory nerve to the joint (medial branch nerve) can be identified and ablated to obtain long-term pain relief with a technique called radiofrequency medial branch neuroablation. For this intervention, the medial branch nerve is first blocked with local anesthetic to confirm that the joint is the true source for pain. If the nerve block reduces pain for the duration of the local anesthetic, then the nerve can be coagulated with radiofrequency heat current, rendering the joint anesthetic and reducing pain long term.

The procedure is relatively painless, requires no incision, and is performed as an outpatient procedure. Studies have shown that it is the most effective treatment for facet joint pain after whiplash injury.