Learning About Medial Branch Block

A medial branch block is an injection (shot) of medicine used to diagnose and sometimes treat neck and back pain.

It is used to numb the medial branch nerves around the facet joints in your spine. Facet joints connect the vertebrae (bones) of the neck (cervical), upper and middle back (thoracic), and lower (lumbar) spine. If the facet joints get inflamed or hurt, they can cause pain and stiffness. If they get inflamed in your neck, you may feel pain in your shoulder. If facets in your lower back get inflamed, you may feel the pain down in your buttocks, groins, hips, or thighs.

A medial branch block can help doctors find out if facet joints are causing your pain. If a facet joint is inflamed or hurt, the nerves around it send a pain signal to your brain. A medial branch block stops that pain signal by numbing the nerves until the medicine wears off. So if your pain gets better after you get the block, doctors can narrow down the cause and make a treatment plan. This is called a diagnostic medial branch block.

Sometimes it may also be used to treat pain from an inflamed or hurt facet joint. If that’s the case, the injection you get may have steroids (medicine to reduce inflammation) as well as an anesthetic (numbing medicine). This is called a therapeutic medial branch block.

Before the block, make sure to:

• Tell your doctor about any medicines or supplements you take. This is especially important if you take blood thinners, since those medicines could cause problems during the procedure.
• Let your doctor know if you might be pregnant.
• Follow any directions your doctor may give you for not eating or drinking before getting the block.

You might get a sedative (medicine to help you relax) through a needle in your arm. Depending on the type of injection, you’ll lie on an exam table either on your side or your belly. Then your doctor or nurse will clean your skin with an antiseptic and numb the skin where the needle will be placed.

To find the right spot to place the block, your doctor will use fluoroscopy (a type of X-ray) to help guide them. They’ll use a thin needle to inject the medicine near the facet joint to numb the medial branch nerve.

You’ll probably go home about an hour after the procedure. If you had sedation to help you relax, you’ll need someone to drive you home from the hospital. Most people can resume their normal activities within a day or two.

If you had a diagnostic block, the effects will likely wear off after a few hours. Write down if your pain got better and how long relief lasted. This will help you and your doctor learn more about your pain and decide on next steps.

If you had a therapeutic block, the effects may last for a few hours, days, or weeks. It all depends on the type of medicine you got, the dose, and how well your body responds to the medicine. If the medicine you got had steroids in it, it may take a few days for your pain to get better. Before the steroids start to work, the area where you got the block may be sore for a few days.

There's also a chance that the block won’t work to relieve pain. If that happens, you’ll work with your doctor to try other things.

The most common side effect from a medial branch block is bruising or pain where you got the injection. It usually goes away within a few days.

Serious problems are rare, but they can happen. These include:

• Infection or bleeding.
• Nerve damage.
• An allergic reaction to a medicine.
• Local anesthetic systemic toxicity (LAST), a rare problem that can happen if the medicine is absorbed into the bloodstream too quickly.

Contact your doctor now or seek immediate medical care if:

• You have symptoms of infection, such as:
  • Increased pain, swelling, warmth, or redness.
  • Red streaks leading from the area.
  • Pus draining from the area.
  • A fever.
• You have severe pain.
• You have numbness or weakness that’s getting worse.