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Thoracic Medial Branch Block

A thoracic medial branch block is an outpatient procedure for diagnosing and treating upper and middle back pain. This information has been provided by your doctor so you can better understand this procedure. Your doctor will make the best recommendation for your specific needs.

What are thoracic facet joints?

Facet joints connect the vertebrae, the bones of the spine. They help guide your spine when you move. The area of the spine between your neck and low back is called the thoracic region. It contains twelve vertebrae. Facet joints are found on both sides of the spine. Each is about the size of a thumbnail. Thoracic facet joints are named for the vertebrae they connect and the side of the spine where they are found. The right T4-5 facet joint, for example, joins the 4th and 5th thoracic vertebrae on the right side. Medial branch nerves are found near facet joints. They transmit pain signals from the facet joints to your brain.

What is a thoracic medial branch block?

During this procedure, a local anaesthetic (numbing medicine) is injected near the medial branch nerve, which stops the transmission of pain signals from the facet joint. If your pain is reduced and you are able to move your back normally, then the doctor will know which facet joint has been causing your pain.

What happens during an injection?

A local anesthetic is used to numb your skin. The doctor will then insert a thin needle near the medial branch nerve. An X-ray machine will be used to ensure the safe and proper position of the needle. Once your physician is sure the needle is correctly placed, the medicine will be injected.

What happens after an injection?

You will be monitored for up to 30 minutes after the injection. You will be advised to keep a pain diary for the next 24-72 hours. Keeping track of your pain helps the doctor know what the next step will be. You may want to check for pain by moving your upper back in ways that hurt before the injection, but do not overdo it. You may feel immediate pain relief and numbness in your back for up to six hours after the injection. This means the medication has reached the right spot. You should be able to return to work the day after the injection, but always check with your doctor.

How long can I expect pain relief?

How long you can expect pain relief depends on how many areas are injured, and on the amount of inflammation. If your pain goes away for a short time, but then returns, you may be a candidate for radiofrequency ablation (RFA) to the medial branch nerve. This procedure provides a more permanent disruption of pain signals.

Before Your Procedure


  • Have nothing to eat or drink for six hours before your procedure (you may drink a small amount of water only up until you leave home on the morning of your procedure)

  • Arrange for an adult to escort you home by car (you cannot drive for 24 hours after your procedure)

  • Arrange for an adult to be present with you for 24 hours following your procedure

  • Notify your Doctor if you are taking any blood thinning or diabetic medications

Following Your Procedure


  • You will usually be discharged after two to three hours

  • Do not drive or operate heavy machinery for twenty-four hours following the procedure

  • You may have minor bruising and pain around the injection site

  • Please confirm your appointment to follow up with your Doctor in two to four weeks following the procedure

  • There are no limitations to your physical activity level following this procedure

Complications & Side Effects


  • Pain and bruising over the injections site

  • Potential risk of blood vessel, nerve and spinal cord injury

  • Potential risk of introduction of infection

  • No or partial response to the procedure

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