Medial Branch Block

chronic pain pictureThe medial branch nerves are a small mass of nerves that come out of the facet joints in the spine, which are part of the bony framework. These small bony projections stem off one vertebra, and they meet with the bony projections of the above vertebra.

These nerves carry pain signals from the facet joints to the brain. These facet joints become inflamed, painful, and stiff due to certain spinal conditions, such as facet joint syndrome and spinal arthritis. The medial branch block involves injecting an anesthetic near these nerves.

What is a medial branch block?

A medial branch nerve block is a procedure that involves the injection of an anesthetic near these nerves, which connect to a specific facet joint. Several levels of the spine are usually injected during one medial branch block procedure.

When the patient has significant relief of pain immediately after the injection, then the facet joint is determined to be the source of pain.

Why is the medial branch block performed?

Due to chronic spine conditions, the affected cervical (neck) facet joints cause a pain that radiates across the neck and shoulders. The pain of the cervical facet joints worsen when the head turns from side to side and up and down.

When the lumbar (low back) facet joints are affected, the pain radiates across the lower back and down the buttocks and upper thighs. The medial branch nerve block is primarily performed as a diagnostic procedure.

If the patient enjoys an appropriate duration of pain relief following the block, then he/she is deemed a Medial Branch Nervecandidate for a subsequent procedure called a medial branch radiofrequncy neurotomy. The neurotomy is a form of nerve ablation that offers long-term pain relief.

What happens before the procedure?

You will be asked to withhold food or drink six hours before the procedure. Also, certain medications will be held before the procedure, such as blood thinners. You are permitted to take certain blood pressure medications with a small sip of water.

After you arrive at the medical center, you will be given instructions, informed of the benefits and risks of the block, and asked to sign a consent form. You should make arrangements to have someone drive you home after the procedure. The nurse will insert an intravenous (IV) catheter into your arm, and monitor your vital signs and oxygen level.

What can I expect during the procedure?

The medial branch block is done with you lying on your stomach for back injections, or on your side for neck injections. The skin along the spine is cleansed with an antiseptic solution, and very small needles are inserted along the bony landmarks to mark the area of injection at the medial branch nerves.

The doctor will inject a small amount of an anesthetic along each nerve. The actual injection only takes a few minutes, but you will be at the facility for approximately one hour.

Does the medial branch block procedure hurt?

The doctor will first inject a small amount of the anesthetic using a very fine needle into the skin. This feels like a pinch and slight burning. Also, the IV sedation used will keep you comfortable so you don’t feel much pain.

Some patients become drowsy, and others have little or no memory of the procedure. After the procedure, you will notice that your pain has eased due to the effect of the local anesthetic.

What can I expect after the procedure?Medial Branch Blocks

The patient should take it easy for a day or two following the medial branch block. The doctor will allow you to use the bathroom and perform some activities, but no heavy work is allowed. The doctor will advise you on when it is safe to return to work.

What are the risks and complications of a medial branch block?

The procedure has few risks and complications overall. However, as with other minimally invasive procedures, there are a few. These include temporary pain at the injection site, bleeding, nerve damage, infection, and no relief of previous pain.

Does the medial branch block work?

The medial branch block is a safe and effective minimally invasive procedure. In a large controlled randomized study involving 100 patients with chronic back pain of facet joint origin, results showed significant pain relief and functional status improvement in 84% of patients.

In addition, the majority of participants also had improvement at a 2-year follow-up. In another study of more than 100 patients with cervical (neck) pain, results showed lower pain scores and significant pain relief (50% or more) at 3, 6, and 12 months. In addition, functional improvement was show at a 12-month follow-up.

Resources

Manchikanti, L, Singh, V, Falco, FJE, Cash, KA, et al. (2012). The Role of Thoracic Medial Branch Blocks in Managing Chronic Mid and Upper Back Pain: A Randomized, Double-Blind, Active-Control Trial with a 2-Year Followup. Anesthesiology Research and Practice, Volume 2012 (2012), Article ID 585806, 10 pages. DOI:
http://dx.doi.org/10.1155/2012/585806

Manchikanti, L, Manchikant, KN, Damron, KS, & Pampati, V (2004). Effectiveness of cervical medial branch blocks in chronic neck pain: a prospective outcome study. Pain Physician, 7(2), 195-201.