What is a facet block or medial branch block?

Often the arthritic spinal joints (facet joints) are inaccessible to the needle due to loss of joint space. Then, we try to block the nerves that carry noxious sensation from the affected joints to the spinal cord. The nerve that carries sensation from the facet joint is called the facet nerve or the medial branch of the spinal nerve.

A facet block is an injection of local anesthetic and steroid into a joint in the spine. A medial branch block is similar but the medication is placed outside the joint space near the nerve that supplies the joint called the medial branch (steroid may or may not be used). You may require multiple injections depending upon how many joints are involved. Facet blocks and medial branch blocks are typically ordered for patients who have pain primarily in their back due to arthritic changes in the facet joints or for mechanical low back pain.

A facet nerve block or medial branch block is a diagnostic procedure. Long term pain relief is not expected. If there is short term pain relief, then we will go ahead with a permanent block. The permanent procedure is called radio frequency ablation of the facet nerve / medial branch of the spinal nerve.

What are the risks of the procedure?

As with most procedures there is a remote risk of bleeding, infection, nerve injury, or allergic reaction to the medications used. Though in theory we may anticipate a long list of side effects but in our clinical practice we have never seen significant side effects. We take extreme care to avoid preventable risk factors.

Will the injection hurt a lot?

Most people say the stinging/burning of the numbing medicine is the most uncomfortable part of the procedure though every person's response to any procedure may vary.

What happens during the actual procedure?

After signing a consent form and checking your blood pressure and pulse, the procedure will be done in the fluoroscopy (x-ray) room with you lying on your stomach. For procedures in the neck an intravenous line may be started. The procedure site is then cleansed with an antiseptic solution. Please let us know if you are allergic to betadine. Sterile drapes are placed. The skin is anesthetized (numbed) with a local anesthetic. This is felt as a stinging or burning sensation. Using x-ray guidance, needles are then advanced to the appropriate locations (the joints or the medial branch). Once the needles are in the proper location local anesthetic with or without steroid is injected through the needles and the needles are removed. Your skin will be cleansed and band-aid will be applied. (The band-aid can be removed on the next morning). Your blood pressure will be checked and you will be discharged to leave with your ride after M.D. authorizes discharge.

What happens after the diagnostic procedure?

Your back pain may be improved immediately after the injection from the local anesthetic. It is important to keep track of how you feel for the remainder of the day. You will be given a pain diary or log to record pain intensity during the first 4-6 hours after the procedure. You should return the pain log next day by fax or mail. We will analyze your response to the temporary block, and will contact you by phone to advice further.

It is important that you keep track of the amount of pain relief you received as well as how long the pain relief lasted.

Some local tenderness may be experienced for a couple of days after the injection. Using an ice pack three or four times a day will help this. Please try to avoid taking pain medications after the procedure.

Will I have any restrictions on the day of the procedure?

You may not drive for the remainder of the day after your procedure. An adult must be present to drive you home or to go with you in a taxi. The procedure will be cancelled if you don't have a responsible adult with you!! This is for your safety.

No heat is to be used in the injected areas for the remainder of the day. No tub bath or soaking in water (i.e. pool, Jacuzzi, etc.) for the remainder of the day.

For what reasons should I call the Pain Management Center after the injection?

If you experience severe back pain, new numbness or weakness of your legs, or signs of infection in the area of the injection, you should call immediately or go to the nearest emergency room.