The spine is full of joints (called Z-joints or “facet” joints) which allow you to bend forward and back, or nod your head. Like any other joint in the body, these joints have joint fluid and cartilage that can develop arthritis or other painful conditions. Every spine segment is connected to the adjacent segment (above and below) by two joints; one on each side. A few of these joints, because of their location, are more prone to injury or arthritis than the rest. Facet joint injections, medial branch blocks and radiofrequency neurotomy are ways of diagnosing and treating pain coming from these joints.
Although some clues can be detected during the history and physical exam, these are not enough to make the diagnosis. Similarly, x-rays and MRIs can show arthritic joints, but not all arthritic joints are painful, and not all painful joints are arthritic. To really be sure that a joint is responsible for your pain, diagnostic blocks must be performed.
Diagnostic blocks consist of injecting a local anesthetic into the joint in question, or onto the nerves (medial branches) that supply sensation to that joint. When the joint is injected ,typically a small amount of cortisone goes with it, which can provide long acting pain relief. In either case, the joint will become anesthetized for the duration of action of the anesthetic. If your pain disappears during that time, we have found our painful joint. If the pain does not disappear, or the relief does not last long enough, we must continue looking. In order to prevent a “false positive” response, or a placebo effect from misleading us, the diagnostic block is always performed twice. If a joint injection does not provide long lasting relief, and the facet joints are the source of the pain, RFA can be considered.
Sensation (and therefore, pain) is transmitted from the facet joints to the spinal cord (and then the brain) first through tiny nerves called Medial Branches. These medial branches also supply sensation to small patches of skin in the back, and movement to tiny muscles on the spine, called multifidi. Blocking these nerves would block sensation from the joint they supply. Because the multifidi muscles are so small, an individual muscle does very little by itself, and blocking the nerves to one or two of them has no effect on movement or stability of the spine.
“Neurotomy” means cutting a nerve. “Radiofrequency” is the method of cutting that nerve. Essentially it involves burning or cauterizing the nerve. Under x-ray guidance, a special needle with insulation all along it’s length except for a tiny exposed tip is placed into position so that the tip is lined up with the medial branches. A small electrical current is then passed through the needle to verify its placement. Once verified, the tip is heated so that the underlying nerve is burned. A local anesthetic is given to relieve pain during the procedure.
All medical procedures have risks. As in all injections, there is a small risk of infection and of bleeding (you must stop all blood thinners before this procedure). In this case, there is a risk of burning an unintended structure; this risk is minimized by using x-ray guidance and test stimulations.
Typically, pain relief will last from a year to eighteen months and then can gradually return. This is a sign that the nerve has grown back. The procedure may be repeated as many times as is necessary.
If you are on any blood thinners (Coumadin, Plavix, Aggrenox, Aspirin), are taking any anti-inflammatory medicines, have any disorders of blood clotting, or have any questions regarding medications to take, please discuss it with the doctor.
Do not eat or drink after midnight the day prior to the procedure.
Regular medications should be taken with a sip of water the morning of the procedure. If you are taking medications for diabetes, please consult with your doctor for instructions.
You should not drive after the procedure. Please arrange for transportation. Prepare to spend around 2 hours.
Do not plan on working or traveling the day of the procedure.
Do not sit in a bathtub, pool, or hot tub for at least 48 hours after the procedure-showering is okay the day after.
Your back may be sore from the needles when the anesthetic wears off. Ice is best for relieving this. Wrap some ice in a towel and try 15 minutes on and 15 minutes off for an hour or so.