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NOTE: Only MDs or DOs Trained in Pain Medicine Should Administer These Injections

The zygophasial joints are also called the facet joints and are located in the back of the spine. They prevent excessive twisting of the spine in the low back, and excessive extension in the neck. Damage to the joints can occur due to trauma (automobile accidents, falls), arthritis, infection, disc degeneration, or in the low back: repetitive lifting of heavy objects for many years. Pain from the facets cannot be definitely diagnosed by x-ray, CT scan, MRI, or Bone scan. The diagnosis is made by precision injection of a local anesthetic or other substance onto the medial branch nerve (nerve to the facet joints). If your pain is relieved 75% or more by this injection you may benefit from Radiofrequency Neurotomy or ablation, for longer term pain (6-18 months) relief. If the relief is less than this amount, you may have other problems in your spine that should be addressed with other therapies.

What is a Medial Branch Block?

A medial branch block involves the x-ray guided injection of a medication the low back medial branch block and face down or on your side for the neck (cervical) medial branch blocks. After skin preparation with a sterile cleaning agent, a small amount of local anesthesia is injected into the skin. Sedation is usually not given as this is a diagnostic test whose outcome depends on your ability to perceive pain relief. A thin needle is guided onto the medial branch nerve and a small amount of iodinated x-ray dye is injected to assure proper placement, then a medication will be injected and the needle is removed. Usually 2-3 injections are required at the time of the procedure. After the injection, you will have your pain and function briefly assessed, then you will go home where you will continue to assess the outcome of the block over the next several hours. The time period for which relief is perceived and the degree of relief (pain scale or other) is important information that is used to direct further therapy.

Do the Injections Hurt?

Usually the actual injections do not hurt very much because only a thin needle is used and is not inserted into the joint.

Special Instructions:

  1. If sedation is not scheduled, you may eat and drink on the day of the procedure.
  2. However if sedation is scheduled, then you should have nothing to eat or drink after midnight on day of the procedure except to take your regular medications.

Do NOT stop any of your medicines on the day of the procedure

– unless otherwise instructed by your pain specialist.


Bleeding, infection, abscess, nerve injury, spinal injury, temporary dizziness or nausea for injections in the neck – these are all very rare occurrences when the injections are performed correctly by a board certified interventionalist.

After the Procedure:

You will be in our clinic for about 30-40 minutes after the procedure and will have your pain and function assessed before discharge. You should not have any leg weakness or significant numbness at the time of discharge.

Discharge Instructions:

  • Activity: Resume normal activity today.
  • Diet: Resume normal diet
  • Medications: Resume normal medications unless otherwise instructed
  • Dressing: You may have small band-aids placed over the injection site. This can be removed the next day
  • Discomfort at the Injection Site: If there is discomfort at the injection site, apply ice wrapped in a washcloth for short periods of time (20 minutes per hour) during the first 24 hours, then apply low to medium heat
  • Side Effects: Possible side effects of local anesthetics used include numbness of the leg or arms, depending whether the test was in your back or neck. Let us know if this occurs. If you experience new onset severe generalized weakness during the first week after the injection, call our office. If you develop fever of more than 102 degrees during the first few days after the injection or severe increase in pain in the back, notify our office, or if it is after hours go to an Emergency Department or Urgent Care, and explain the procedure you have had and the symptoms.

Return to Normal Activities:

You may experience some numbness in the skin over your back during the first several hours. Relief from the diagnostic injection may last up to 12 hours or longer.

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