What is a facet injection or medial branch block?
An inflammation of the joints between the spine bones is common reason for Back Pain. When this does not respond to the usual Painkillers, the best alternative is an injection of local anesthetic and steroid into the joint per se. This is called a facet joint injection.
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.
A facet injection or medial branch block may be therapeutic and/or diagnostic. One of three things may happen:
- The Pain does not go away – which means that the Pain is probably not coming from the blocked facet joints – this has diagnostic value.
- The Pain goes away and stays away for a few hours but the original Pain comes back and doesn¹t get better again. This would mean the block was also of diagnostic value -the Pain is probably coming from the joints, but the steroid was not of benefit.
- The Pain goes away after the block, it then may come back later that day, but then the Pain gets better again over the next few days. This means that the block was of therapeutic value – the steroid had a long lasting effect on the Pain.
If you improve for a long period of time, the injections may be repeated, as needed. If you improve for a short period of time another procedure (radiofrequency lesioning) may be performed for a longer Pain relief effect.
Note: The procedure cannot be performed if you have an active infection, flu, cold, fever, and high-uncontrolled blood pressure or if you are on blood thinners. Please make your Pain doctor aware of any of these conditions. This is for your safety!
What are the risks of this procedure?
As with most procedures, there is a remote risk of bleeding, infection, nerve injury, or allergic reaction to the medications used.
Some short-term side effects may occur. If local anesthetic spreads to nearby nerves you may have weakness or numbness that can last for few hours. If this happens you may have to stay in the Pain Management Center until this resolves. You may have increased Pain for a few days after the injection, including localized Pain at the injection site. Diabetics may have short-term elevation of blood sugars. People prone to fluid retention may have increased fluid retention for 1-2 weeks.
Will the injection hurt a lot?
Most people say the stinging/burning of the numbing medicine is the most uncomfortable part of the procedure.
What happens during the actual procedure?
Make sure that all your questions will be answer before signing the consent form. Once that is done, you vital signs will be checked and if all within normal range, the procedure will be started under fluoroscopy (x-ray) guidance, with you lying on your stomach. For procedures in the neck an intravenous is started. The back is then cleansed with an antiseptic soap. Sterile drapes are placed. The skin is anesthetized (numbed) with a local anesthetic. This is felt as a stinging or burning sensation for few seconds only. Using x-ray guidance, needles are then advanced to the appropriate locations (the joints or the medial branch). Once the needle tip is felt to be in the proper location local anesthetic with or without steroid is injected and the needles are removed. Your skin will be cleansed and a band-aid will be applied.
How will I feel after the injection?
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. The steroid, when used, takes two or three days to have on effect in most people and peaks in about two weeks.
Some local tenderness may be experienced for a couple of days after the injection. Using ice packs three or four times a day will help this.
You may take your usual Pain medications. It is important that you keep track of the amount of Pain relief you received as well as how long the Pain relief lasted.
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 or on public transportation. The procedure will be canceled 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.
If the injections are in your neck you may take your medications as usual with a sip of water, but do not eat or drink for six hours before the procedure. You may eat, drink and take your medications as usual on the day of the procedure (both before and after) if the injections will be in your low back. Please follow the above instructions unless told differently by your Pain doctor.
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 the Pain Management Center right away at (401) 729-4985 during office hours or go to the closest emergency room if after office hours or on holidays and weekends.