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Study questions need for facet joint diagnostic injections.

2 Reasons to Skip Diagnostic Injections for Facet Joint Pain

Is there anyone who looks forward to getting a shot? Even though today’s needles are incredibly thin, and doses for things like a flu vaccine are relatively tiny, I suspect that most people experience momentary fluttering in their stomach or a slight increase in heart rate as the needle penetrates skin and the plunger goes down. There’s even a phenomenon called injection phobia that affects as many as 10% of people. The point is, pretty much everyone would just as soon not get any injections if they weren’t necessary.

While most shots are no big deal, an injection into the spine can range from uncomfortable to very painful. However, such a procedure is defined as necessary when it comes to diagnosing possible facet joint pain from spinal arthritis. As with any cartilage-lined joint such as the knee, the cartilage that protects the joint and facilitates smooth movement can wear thin due to aging, injury or disease. The small facet joints between every vertebra (back bone segment) are just as susceptible to wear and tear as any other joint. When this happens in the lower spine, it can lead to low back pain. But because there are many things that can also cause low back pain, it’s important to pinpoint the cause, often a process of ruling things out.

Let’s say that for a given patient, muscle pain, other soft tissue injury, and tension have all ruled out. The patient has tried physical therapy, chiropractor visits, heat/cold applications, anti-inflammatories, exercise, posture improvement…all to no avail. The doctor suspects facet joint arthritis and wants a diagnosis ASAP. The current protocol calls for x-ray guided nerve block injections into facet joints to see if the pain goes away. If it does, eureka! The doctor can proceed with recommending treatment, usually temporary injections or radiofrequency burning of the nerve to block pain signals to the brain.

It turns out that the diagnostic injections may not be necessary, partly because they increase the cost of treatment and partly because nerve ablation seems more effective without the diagnostic step. A study out of Johns Hopkins Medical Center and Walter Reed Army Medical Center calls into question the merits of the diagnostic injections1. These anesthetic injections may be done twice: the first time to confirm that the arthritic facet joint is the cause of the pain, and the second must be done before the radiofrequency procedure to validate the need for that procedure (which also uses a needle inserted to burn the nerve that serves the facet joint). I want to point out that the diagnostic injection is usually tolerable as the anesthetic is administered little by little as the needle advances, but some people report agonizing pain – and residual pain when the anesthesia wears off.

For the study itself, which had 151 participants, the research team compared the cost-effectiveness of 1 diagnostic injection, 2 diagnostic injections, and no diagnostic injections before radiofrequency nerve ablation. The average cost for the pre-ablation injections was higher than the ablation cost itself. In addition, a higher percentage of patients in the no-injection group experienced pain relief from the ablation than patients in the two groups that had 1 or 2 diagnostic injections. According to one news article, “Their conclusions show treatment without diagnostic tests have a lower cost to the healthcare system and result in more patients experiencing relief of their pain…Their recommendation would treat more people through radiofrequency neurotomy and less people would be tested using diagnostic nerve blocks.”ii

It’s a good day when a procedure can bring pain relief, and radiofrequency needle ablation of the nerve has helped 30-50% of patients experience great relief, even zero pain, for up to two years. However, both diagnostic injections and radiofrequency needle ablation have risks that include:

  • Infection
  • Skin numbness
  • Muscle spasms/increased pain
  • Spinal nerve damage leading to permanent pain

The Sperling Medical Group offers noninvasive diagnostic MRI imaging for facet joint arthritis. In addition, a noninvasive procedure called MRI-guided Focused Ultrasound (MRgFUS) is done without x-rays or anything inserted through the skin. Instead, MRI identifies the target nerve, guides the application of focused beams of ultrasound that create heat where they meet at the nerve, and monitors the temperature at the site of ablation to be sure it’s high enough to block the nerve impulses but safe for surrounding tissues.

As research advances, we are learning a lot about ways to reduce healthcare costs yet improve the patient’s treatment experience and quality of life afterwards. MRgFUS is a revolutionary technology, and treating facet joint pain is just one of many present and future applications. For more information, contact the Sperling Medical Group.


Facet Pain