Root Blocks

A root block is an injection of local anesthetic and steroid injected under x-ray guidance into the area where the nerve exits the spinal column. A root block is usually ordered by your doctor for pain in the arm or leg that follows the path of a single nerve.

A root block may be diagnostic and/or therapeutic. One of three things may happen:

  • The pain does not go away, which means that the pain is probably not coming from the nerve at the level of the injection. This has diagnostic value.
  • The pain goes away and stays away for a few hours, but the original pain comes back and does not get better again. This would mean the block was also of diagnostic value, indicating that the pain is probably coming from the nerve at the level of the injection but the steroid was not of benefit.
  • The pain goes away after the block and 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, because the steroid had a long-lasting effect on the pain.

If you get a positive, lasting benefit from the injection, the block may be repeated. Sometimes your surgeon will ask that the block be done to help identify whether or not surgery might be helpful and at what level the surgery might be most helpful.

What are the risks of the procedure?

As with most procedures, there is a rare risk of bleeding, infection, nerve injury or allergic reaction to the medications used.

Some short-term side effects may occur. You should get some numbness that follows the path of the nerve that was blocked. You may get some weakness as well. If you get weakness that interferes with your ability to walk, you will have to remain in the Pain Management Center until this resolves, usually several hours.

You may have increased pain for a few days after the injection, including localized pain at the injection site. People with diabetes may have short-term elevation of blood sugars. People prone to fluid retention may have increased fluid retention for one to two weeks.

The procedure cannot be performed if you have an active infection, flu, cold, fever, very high blood pressure or if you are on blood thinners. For your safety, please make you doctor aware of any of these conditions.

Will the injection hurt a lot?

Most people say the stinging/burning of the numbing medicine is the most uncomfortable part of the procedure although every person's response to any procedure is individual. As the injection is right near a nerve, it is possible to get a temporary shock-like sensation.

What happens during the actual procedure?

After you sign a consent form and your blood pressure is checked, the procedure will be done in the fluoroscopy (x-ray) room with you lying on your stomach. For procedures in the neck, an intravenous is started.

Your back or neck is the 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. Using x-ray guidance, the needle is advanced to the proper location. A dye may be injected at this point. Please let the doctor know if you have any allergies to dye.

Local anesthetic and steroid are then injected through the needle and the needle is removed. Your skin will be cleansed and a bandage will be applied. The bandage can be removed the next morning. Your blood pressure will be checked, and you will be able to leave with your ride after the doctor authorizes your discharge.

How will I feel after the injection?

Your 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 usually takes two to three days to have an 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 an ice pack three to four times a day will help this. You may take your usual pain medication as well after the injection.

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. For your safety, the procedure will be cancelled if you do not have a responsible adult with you.

No heat is to be used in the injected areas for the remainder of the day. You should not take a tub bath, hot shower, or soak in water (such as a pool or hot tub) 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 are in your low back. Please follow these instructions unless told differently by your doctor.

For what reasons should I call the Center for Pain Medicine 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 Center for Pain Medicine at 617-732-9060.

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