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Medial Branch Blocks

A medial branch block is an injection of a local anesthetic (numbing medication) near the medial branch nerves. These small nerves carry pain signals from the facet joints of the spine.

The facet joints are located between the vertebrae; there are two facet joints between each pair of vertebrae. The facet joints provide stability while allowing the spine the ability to bend and twist. With wear and tear and with normal aging, the facet joints can become painful.

Patient guidelines (PDF) ›

Procedure overview (PDF) ›

What is the goal of a medial branch block?

The goal of medial branch blocks is to temporarily numb the facet joints to see if they are causing your pain.

If you experience pain relief immediately following the procedure, your physician is assured that one or more facet joints are causing your pain. However, medial branch blocks are only a way to diagnose the cause of your pain, and they are not expected to produce pain relief for more than a few hours.

If medial branch blocks produce temporary relief, then radiofrequency treatment may be used to produce long-term pain relief.

What happens before treatment?

You will be escorted to a room where a nurse will conduct a pre-procedure interview.

The physician who will perform the injection reviews your medical history, previous imaging studies, current medications and physical exam results in order to help plan the best approach for the injection. If you have not had a physical exam prior to the injection, the physician will perform an exam at this time.

What happens during the procedure?

You will remain awake during the entire process. Blood pressure, heart rate and breathing are continually monitored.

After you are lying face down on the procedure table, the injection site is cleansed with an antiseptic. This procedure involves inserting a needle through the skin, muscle and soft tissues, so there is some slight discomfort involved. An injection of local anesthetic (numbing medication) will be administered in the area where you are experiencing pain.

This procedure takes approximately 30 minutes.

Should I limit my activity or change my diet after the injection?

No. Unless your doctor tells you otherwise, you may return to your usual activities and resume your normal diet immediately after the injection.

Are there any side effects caused by a medial branch block?

Side effects are uncommon following a medial branch block; however, you may experience the following:

  • Immediately after the injection, you may feel that your pain is gone or is much less. This pain relief is often the result of the local anesthetic and will usually only last a few hours. Your usual pain will follow.
  • You may experience mild pain at the site of injection for several days. You may also experience a temporary increase in your usual pain after the injection. You can apply ice to the area for as long as 15 minutes, three to four times a day.
  • You may experience some dizziness during or soon after the injection.

Are there any restrictions after a medial branch block?

Yes. You should follow these restrictions after the injection:

  • Do not drive for the remainder of the day.
  • Do not take a tub bath or soak in water (pool, hot tub) for 24 hours after the injection.
  • Allow three days after the injection before resuming physical therapy.

What are the medications used for a medial branch block?

Lidocaine or bupivacaine are local anesthetics that are used to numb the area of injection; this numbness usually wears off within two to six hours.

When should I call my doctor?

You should call your doctor immediately if any of the following occurs:

  • Swelling, redness, bleeding or discharge from the site of the injection
  • A fever greater than 100 ˚F
  • New or worsening back or neck pain
  • New numbness or weakness in your arms or legs
  • Difficulty with urination after the injection, such as suddenly losing control of your bladder
  • Difficulty with bowel movements after the injection, such as suddenly losing control of your bowels
To be seen by one of our specialists, call 949-UCI-PAIN (949-824-7246) or request an appointment online ›

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To reach a doctor or nurse during business hours (Monday through Friday, 8 a.m. to 4 p.m.), call 949-824-7246 and leave a message. Your call will be returned within 12 business hours.

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