The spine is designed to bend and turn. Along with the intervertebral discs, facet joints (also referred to as Z joints or zygapophyseal joints) enable the spine to bend and twist. Each vertebra has two sets of facet joints. One set of facet joints is located at the top and a corresponding set is at the bottom.
Facets joint are small joints a little larger than the size of your thumbnails located in pairs on the back of your spine. They provide stability and guide motion in your back. If the joints become painful they may cause pain in your neck, shoulder, low back, abdomen, buttocks, groin or legs. The pattern and location of pain helps to determine the likely facet joints involved.
Working like a hinge, the articulating surfaces of each facet joint are coated with smooth cartilage allowing friction free movement. Although the facet joint bones fit snugly together, there is a lubrication system. The lubricating ‘oil’ is called synovial fluid and resembles uncooked egg whites. This fluid also nourishes the cartilage tissues. A block that is performed to confirm that a facet joint is the source of pain and decrease pain and inflammation in a facet joint or joints.
Just as imaging studies demonstrate typical patterns of facet joint degeneration, patients with facetogenic pain often have a typical history and physical examination suggestive of this disease. This is sometimes referred to as “Facet Syndrome”.
The exact definition and what constitutes the ‘Facet Syndrome’ is somewhat controversial, but includes the following:
The procedure is explained to the patient, questions are answered and informed consent is obtained.
You will be placed on the x-ray table on your stomach in such a way that your doctor can best visualize these joints in your back using x-ray guidance. The skin on your back will be scrubbed using a sterile scrub (soap). Next, the physician will numb a small area of skin with numbing medicine. This medicine stings for several seconds.
Immediately after the procedure, you will get up and walk and try to imitate something that would normally bring about your usual pain. You will then report the percentage of pain relief and record the relief you experience during the next week.
You should not drive the day of the procedure. Your legs may feel weak or numb for a few hours.
If you don’t get relief from the facet joint injections, it is unlikely that this is a source of your pain. You should then consider with your physician the other possible sources of your pain. This may include other diagnostic blocks or imaging studies.
This is the most common scenario with facetogenic pain. Typically the local anesthetic wears off over the next six hours and the pain may return. After a series of successful diagnostic facet blocks, the next step is usually to proceed with a Radiofrequency Neurolysis (RF)
As with any procedure, there is a risk of significant complications. The most common side effects from the joint injection include (but are not limited to):