Radiofrequency Ablation (RFA) of medial branch nerves is a very well-studied and established tool for management of facet joint pain. Facet joints, otherwise known as zygapophyseal joints, are located at the back of the bony spinal column from the top of the neck to the bottom of the low back. Part of their role is to dictate planes of motion of the spine, but their main role is to help bear load through the spinal column. Unfortunately, similar to other joints in our body, the facet joints can become painful due to inciting events such as trauma or motor vehicle accidents. Additionally, they can become painful due to age-related arthritic/degenerative changes. In fact, facet joint pain is the most common cause of low back pain in people over 60 years of age.
In patients who have tried and failed conservative treatment options such as medications, physical therapy, and/or chiropractic, further investigation with interventional spine procedures/injections may be considered. But first, it’s important to go through some background information on why and how we feel pain from the facet joints:
- Pain emanating from facet joints travels from the joints and gets picked up by the medial branch nerves
- The medial branch nerves then send the pain signal along different nerves and eventually makes its way to the spinal cord
- The pain signal then travels up the spinal cord to the brain where we actually sense and interpret pain
Now that we have an idea about the pathway of facet joint pain in our nervous system, we can explain the concept behind use of medial branch blocks (MBB) to properly and precisely diagnose facet joint pain. If facet joint pain is considered as a possible cause of neck, low back, or mid back pain, performance of MBB can be performed and works like this:
- Using fluoroscopy (x-ray) for needle guidance, needles are placed at the sites along the spinal column where the medial branch nerves are located
- A small amount of local anesthetic (numbing medication) is placed on the medial branch nerves, temporarily blocking the medial branch nerves’ ability to sense and transmit the pain signal coming from the joints
- The patient is then instructed to keep track of their pain over the next few hours (PLEASE NOTE, THE LOCAL ANESTHETIC IS ONLY MEANT TO LAST A FEW HOURS… MBB ARE ONLY FOR DIAGNOSTIC PURPOSES ONLY)
In patients who experience little to no benefit with MBB, the facet joints are fairly conclusively ruled out as a primary pain generating structure contributing to a patient’s spine-related pain. While potentially frustrating to the patient, it is useful to narrow down potential causes of spine pain so that attention might then be focused on other structures such as disc, nerve , ligament, etc. In patients who experience significant improvement in pain, a second MBB is performed to confirm that the pain is truly coming from the facet joints. Many patients ask why a second MBB is required. First, two diagnostic MBB are performed in order to increase diagnostic precision and decrease likelihood of placebo effect. Second, insurance companies typically require two diagnostic MBB before approving RFA. Essentially, it is important to be as precise and certain of the diagnosis of facet joint pain before proceeding with RFA of medial branch nerves.
Now that we’ve established that the facet joints are the primary cause of spine pain, we can proceed with RFA. How is RFA performed?
- Once again, using fluoroscopy for needle guidance, the needles are placed at the sites along the bony spinal column where the medial branch nerves are located
- Testing is performed to ensure that the needles are placed near the medial branch nerves
- Local anesthetic (numbing medication) is deposited on the medial branch nerves and given some time to settle in
- Then, we warm up the needle tips and create small lesions at the nerves, thus interrupting the ability of the pain signal to be sensed from the facet joint and transmitted along the nervous system. In other words, the spine pain you experience is significantly decreased.
Many studies indicate that RFA of medial branch nerves can provide long-lasting improvement in facet-mediated spine pain. The benefit derived from RFA typically lasts for many months to multiple years. If the pain returns, RFA can once again be performed and provide long-term relief.
If you’re dealing with low back, neck, or mid back pain, please contact Orthopedic Specialists of Northwest Indiana at 219.924.3300 to book an appointment with Dr. Craig Best.
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