What is a medial branch nerve block?

This procedure is considered a "diagnostic" injection. A diagnostic injection is any injection that only uses numbing medicine to numb specific nerves that are suspected of causing your pain. If the pain goes away immediately after the injection, it confirms that the pain was coming from those nerves. This technique is used to find a diagnosis for your pain, hence the name "diagnostic" injection. A medial branch nerve block is done specifically for facet joint pain to figure out which facet joints are responsible for your low back pain. If certain facet joints are irritated from trauma or arthritis, there are nerves around these joints that send pain signals to your brain. When pain signals are sent to the brain, it makes you aware of that pain. By blocking those nerves, there are no pain signals that are transmitted to the brain, therefore no pain is felt at those injured facet joints. 

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Who is a candidate for medial branch nerve blocks?

Medial branch nerve blocks can be done for both neck pain, middle back pain, and low back pain. Those that could benefit from this nerve block have symptoms associated with facet joint pain. This injection is commonly performed when:

• Facet joint injections have not been effective for pain relief

• Further evaluation is needed to pinpoint which facet joints could be causing the pain

• There is a consideration in performing a radiofrequency ablation (RFA)

  • An RFA is a procedure that involves burning nerves that transmit pain signals from the facet joints to the brain. If these nerves are burned, there should be no pain coming from those facet joints​

  • Nerves that are burned by RFA grow back after 6-9 months

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What conditions are these injections used for?

• Facet joint pain

• Facet joint arthritis

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What to expect during the procedure?

The facet joints that are suspected of causing the neck or back pain are identified using an x-ray machine called a c-arm. Most commonly 2-3 facet joints are injected with numbing medication using a thin needle that is guided to the joints with the help of the c-arm. If the pain decreases or completely goes away immediately after the procedure, then it is confirmed that those facets were the cause of the pain. 

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For more information or to discuss an appropriate treatment plan for your neck pain and back pain with one of our specialized pain management physicians, call Saint Louis Spine and Joint Pain Specialists today.

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