Radio-Frequency Neurotomy For Facet Joint Pain
Radio-frequency neurotomy (RFN) involves the destruction or long-term block of small nerves. The radio-frequency generator produces a localized heat lesion to either destroy or deactivate the nerve, while leaving the surrounding region and larger nerves unaffected.
What are median branch nerves?
Median branch nerves are small nerves that branch out from larger spinal nerves exiting the spine. These nerves transmit mostly sensory information. The nerves supply the facet joints, ligaments, skin, and small muscles at each segment. These are NOT the nerves that are responsible for movement of the extremities and sensation in the arms or legs. Each facet joint is innervated by 2 different median branch nerves. Therefore, for a given joint, 2 different nerve branches must be lesioned. A typical procedure will involve 2 levels and may involve each side, so on average about 4-6 needle placements are necessary to cover the area needing treatment.
Which patients are candidates for radio-frequency lesioning of facet nerves?
Patients that have been shown to have pain originating from the facet joints are candidates for this procedure. Injections to block the facet joints and the median branch nerves that innervate the joints are done prior to the lesioning procedure itself, so the process involves at least 2 visits.
What chance is there that the procedure will work?
Studies have shown that there is a 50% chance of significant pain relief following the procedure as far out as two years or longer. About half of the remaining patients get benefit for shorter periods of time and some patients do not get any benefit from this procedure. Overall, 70-80% of patients report satisfaction with the procedure. The nerves do have the capacity to grow back in time. Patients may require repeat lesioning as early as 6 months, usually not for 1-2 years. There are many causes for pain, and this procedure addresses the facet joints predominantly. Other sources of pain, such as nerve compression and disk pain, are not affected.
How is the procedure performed?
The procedure is performed under local anesthetic usually without sedation. Fluoroscopic control (x-ray guidance) is used to help ensure safe and correct placement. In addition, stimulation of the nerves may be used to identify the location of the needle tip. Once proper placement is confirmed, local anesthetic is injected to make the lesioning virtually painless, and the tip of the needle then heats the surrounding tissue, burning an area about the size of the tip of a cotton swab.
How long it does its take for this procedure to work?
Some patients experience relief immediately following the procedure. However, because of injection site soreness, some patients may not have relief for up to 3-6 weeks.
Is the procedure painful?
Because the procedure is performed while the patient is awake, you may feel some uncomfortable sensations at times, mostly during placement of the needles. The lesioning itself is usually painless. After the procedure, patients may also have some injection site tenderness for up to two to four weeks. Patients may take pain and/or anti-inflammatory medications following the procedure.
Are there any risks or complications from the procedure?
Because this procedure is performed under x-ray control and patients are awake, the risk of large nerve injury is very small. Nerve stimulation may be performed prior to lesioning so that large nerves that supply the extremities are not damaged. X-ray control ensures that the needle tip is in a safe location. Patients may also have some numbness of the skin overlying the injection site, which usually returns to normal over 1-2 months.
What if the procedure does not work?
In this case, it may be that the pain generator is in a different location other than that supplied by the median branch nerves that were treated. For instance, there may be adjacent facet joints causing pain that were not specifically treated with the procedure. The patient should be re-evaluated and other diagnostic interventions should be considered. Nerve compression and ligament injury are other common causes of pain that respond poorly to RFN, and each is treated differently (see epidural steroid injection and Prolotherapy, respectively).
Are there any restrictions following the procedure?
There are no restrictions specific to the procedure. You may return to activity when you feel able to do so. Because of soreness, some patients may choose to wait a week or two before planning any major traveling or other strenuous activity.
Does insurance cover this procedure?
Most insurance companies cover radio-frequency lesioning. However, in some cases preauthorization may be required. Your insurance coverage may vary depending on your specific plan and policy.