Radiofrequency ablation (RFA), also called radiofrequency neurotomy is a procedure that involves heating a part of a pain-transmitting nerve with a radiofrequency needle to create a heat lesion. This resulting lesion prevents the nerve from sending pain signals to the brain. RFA treatment typically provides longer-lasting pain relief compared to other therapeutic injections.
Medial or Lateral Branch RFA
RFA to treat neck pain is performed on medial branch nerves that carry pain signals from the facet joints. RFA to treat low back pain or posterior pelvic pain from the sacroiliac joint is performed on the lateral branch nerves.
Diagnostic nerve blocks are usually tried on one or two lateral or medial branch nerves to locate the target nerve. The nerve that responds to the diagnostic block is treated with RFA.
How Radiofrequency Ablation Works
The heat lesion on a nerve may be produced by any one of the following three methods:
- Conventional continuous radiofrequency (CRF) ablation—continuous high-voltage current is passed to produce a heat lesion.
- Pulsed radiofrequency (PRF) ablation—short bursts of high-voltage current are passed with silent phases in between when no current is transmitted.
- Water-cooled radiofrequency (WCRF) ablation—a specialized needle is used that is heated but also cooled by a continuous flow of water to prevent over-heating.
To produce small, well-defined lesions, CRF and PRF are used. To produce larger lesions involving more tissue area, WCRF is used.
Once the RFA lesion is created, the pain-transmitting ability of the nerve fibers is lost and pain signals from the source (facet or sacroiliac joint) do not reach the brain. The effects of RFA may last for a few months to years, after which the nerve usually regenerates, and the pain may or may not return.
Fluoroscopy or x-ray guidance is used to guide the treatment needle to the target nerve.
Success Rates of Radiofrequency Ablation (RFA)
Studies show the following findings on pain-relief obtained from RFA:
- RFA performed for the facet joint may provide pain relief in 45% to 60% of patients.1,2
- RFA performed for the sacroiliac joint may provide pain relief in 75% to 86% of patients.3,4
Success usually depends on the accuracy of diagnosis, variations in the anatomy of the nerve, and the type of technique used. Pain-relief typically lasts from 6 months to 2 years, although some studies have reported relief for up to 3 years.1,5 Additional injections may be given if a good initial response is seen.
When Radiofrequency Ablation (RFA) Is Performed
RFA is considered for treating facet joint pain in the cervical, thoracic, or lumbar spine; or for sacroiliac joint pain in the posterior pelvis.
RFA may be performed in the following cases:
- Vertebral and/or spinal conditions such as degeneration causing neck, mid-back, or low back pain
- Facet joint pain or facet arthritis
- Cervicogenic headache
- Occipital neuralgia
- Posterior pelvic pain stemming from the sacroiliac joint
Side-Effects and Risks of Radiofrequency Ablation (RFA)
For the first few weeks or days, a sunburn type burning and or numbness may be felt over the injection site, typically for RFA performed in the neck. Resting, using an ice-pack, and using topical or oral medications may help relieve the discomfort.
Risks, although rare, may involve infection, adjacent nerve damage, injury to blood vessels, and/or abnormal sensations in the skin over the treatment site.