The vertebral bodies are stacked one on top of another to form the entire structure we call the spine. In between vertebral bodies are tiny joints called facet joints. As arthritic change and inflammation of the joints occur, the nerves to the facet joints can convey severe and diffuse pain. The pain maybe improved for months if the nerve that supplies the joint or the joint itself is blocked.
Radiofrequency is a procedure that uses heat to block a nerve. This is not a permanent block as the nerve, once successfully heated, can still grow and thus the pain may come back.
Success varies in patients. Since there may be many causes for back pain, part of the diagnosis can be made if a facet injection with a local anesthetic causes temporary relief of back pain.
Radiofrequency uses a heating element from the high radio frequency signals much like a microwave heats food. The procedure takes a longer amount of time to perform as the more exact the needle placement, the more successful the outcome.
The procedure of radiofrequency nerve block
The procedure is done much like the facet injection. The needle is placed near the area of the joint where the nerve is located. A stimulator unit is placed over the nerve to reproduce the back pain. If the stimulation does not give a strong response, the needle is repositioned and the nerve is again re-stimulated. This may take a few attempts to ensure that the nerve that is responsible for the back pain is identified. Once the appropriate location of the needle is found, a medication is placed to prevent inflammation and pain when the radiofrequency is turned on. The radiofrequency is done for 90 seconds. A warmth or heat maybe felt at the back during the procedure.
If the procedure is successful, pain relief may vary from 6-12 months or more. If the pain returns before this time, the radiofrequency did not cover the entire nerve. The procedure can be repeated to attempt further blocking of the nerve.