Facet Joint Pain

Facet Joint Pain
(Zygapophysial Joint Arthropathy)

Most often, lumbar pain can been attributed to lumbar disc herniation or to a dysfunctional intervertebral disc. However, there are several other entities that may cause low back pain, including the facet joints, the sacroiliac joints, spinal nerve roots, muscles and ligaments, and other non-spinal causes

In the thoracic spine, each vertebra attaches to a rib on either side. Because of the inherent stability of the rib cage, symptomatic facet joint pain is uncommon in the thoracic spine compared with the lumbar and cervical regions. Facet joint related mid back pain usually follows surgery or trauma to that spinal segment.

In the cervical spine, the facet joints are actually the most common source of pain. Neck pain is attributed to facet joint dysfunction more often than a disc herniation or to a dysfunctional intervertebral disc, combined!

Anatomy

The correct term for the facet joints is the zygapophysial joints. Typically, the zygapophysial joints are referred to as facet joints or z-joints to avoid difficult medical terminology. Each spinal segment has a pair of facet joints. The main role of these joints is to guide the motion of the spine.

Each facet joint is innervated by two nerves (most often the "medial branch of the primary dorsal rami" from two spinal levels). These sensory nerves, which transmit the signal of pain from our facet joints to our spinal cord, plays a vital role in both the diagnosis and treatment of neck and back pain from the facet joints.

The below illustration of the spinal column anatomy illustrates the path of the medial branch nerve (blue arrow). It is this nerve that provides sensation to the facet joint. Each facet joint is innervated by two medial branch nerves.

Signs and Symptoms

Lumbar spine. Low back pain originating from the lumbar facet joints can present in many ways. There exists significant overlap between pain from the facets joints and that of other spinal and non-spinal structures. (e.g. intervertebral discs, spinal nerves, sacroiliac joints, spondylolysis, etc.) Your physician may develop a high suspicion of facet joint pain after listening to your history and performing a proper physical examination; however, research has shown that it is impossible to reliably make a diagnosis without further diagnostic testing.

Thoracic spine. Mid back pain that is derived from the lumbar facet joints is quite rare. When it does occur it often presents with pinpoint pain along the spine. Movements such as lateral bending or lateral rotation, or even overhead lifting may exacerbate the patient's symptoms.

Cervical spine. Neck pain that is derived from the cervical facet joints is actually very common! Research studies show that the cervical facet joints may actually be the most common source of neck pain. However, similar to the lumbar spine, there exists significant overlap between pain from the facets joints and that of other spinal and non-spinal structures (e.g. intervertebral discs, spinal nerves, upper back muscles, muscles, TMJ, etc.). Your physician may develop a high suspicion of facet joint pain after listening to your history and performing a physical exam. Again, it is impossible to reliably make a diagnosis without further diagnostic testing.

Imaging Studies

One must recognize that imaging studies only provide anatomic detail and cannot independently determine the particular source or cause of pain. There are no radiographic studies available at present to conclusively diagnose facet joint pain. Various studies may reveal anatomic abnormalities of the spine. However, they are not diagnostic. Due to the fact that pain is a subjective experience, the spine physician must carefully assess the history and correlate it with the imaging studies. Use of plain radiographs, CT, CT myelography, MRI, bone scans and SPECT can be utilized to provide additional anatomic detail. They can also alert the physician of malignant causes of spine pain.

Diagnostic Injection

Spine physicians may use intra-articular (joint injection) or medial branch blocks (nerve blocks) for the diagnostic work up. If your physician suspects that your back or neck pain is emanating from the facet joints, they must perform a diagnostic injection series to confirm this suspicion. Under live x-ray guidance, local anesthetic is precisely injected to block the nerves that give sensation to the joint in question (medial branch block). If this provides complete or near complete relief of your neck pain, it is likely that the joint is the culprit. However, if you obtain good relief, the block must be repeated a few days later, with a different medication. This is done to make sure your response to the original block was not a false-positive result ("placebo effect"). Believe it or not the rate of false-positives is close to 40%!

Treatment

Various treatment options are available for facet joint pain.

Radiofrequency neurotomy. The standard of care is a radiofrequency neurotomy. Facet neurotomy is a procedure procedure that interrupts the pain signal through a facet joint's nerve. A radio-frequency probe that heats the 2 small nerve branches to each facet joint accomplishes this interruption known as denervation.

Intra-articular steroid injection. There are a definite percentage of patients who suffer from joint pain that will respond the instillation of corticosteroids into the affected joint(s). This is a quick, safe procedure that is easy to tolerate. However it is typically only recommended in select patients because the results from this procedure do not measure up to those of radiofrequency neurotomy.

Physical therapy

• Education and training in proper body mechanics and posture are essential.
• Strength training. A sound foundation for your spine to work from will help with long-term results. Gaining stability in your pelvic and shoulder girdles will set you up for sustained benefit from your facet neurotomy.
• Aquatic therapy. Water based exercises can also be instituted for relief of facet joint pain.