Medial Branch Block

What is a medial branch block and what are facet joints?

Medial branch nerves are very small nerve branches that carry pain messages from the facet joints to the brain where they are experienced. The facet joints are small joints in the back of the spine that form connections between each vertebra. If these nerves are blocked or numbered, they will not be able to transfer the painful sensation from the joints to the brain. Therefore, this procedure is completed to see if your back pain is caused by the medial branch nerves.

How is this procedure performed?

The patient will lie on the stomach. The skin of the back or the neck is cleansed with antiseptic solution and a local anesthetic is injected to number the area. A small needle is then guided using an X-ray to the medial branch nerve which is then numbed. The doctor will then inject a small amount of X-ray contrast to ensure correct needle placement and a local anesthetic, like lidocaine, to numb the nerve.  The injection takes about 15 minutes to complete.

Will the injection hurt?

There is some discomfort with needle insertion which is minimized by numbing the skin over the nerves with a local anesthetic. Most patients only feel the injection of the numbing medication and not the actual needle used to inject the media branch nerves.

How long does the effect last?

The effect will last several hours or more. This is strictly a diagnostic block to test if the medial branch nerves are in fact the source of some of the pain. It is very important for you to fill out your pain diary following the injection and bring it to follow up appointments. Once the aesthetic medical wears off the pain will likely return and you may have some increased soreness for a day or two.

What is the next step after the injection?

If you benefit from the procedure, the next step would be considering of radio frequency treatment of the medial branch nerves. This is a procedure that will provide pain relief for a longer period of time (average of one year). This will be discussed at your next appointment.

What are the risks and side affects?

Serious side effects and complications are rare. The most common problem after the injection is having pain at the injection site for a few days. The other complications are infection, bleeding and nerve injury. These complications are minimized by stopping blood thinners, using sterile technique, and fluoroscopy for x-ray needle guidance.