Medial Branch Blocks

Download the Cervical Medial Branch Block treatment handout

Download the Lumbar Medial Branch Block treatment handout

A medial branch block injection is a procedure that involves injecting a local anesthetic and possibly a steroid medication near the medial branch nerves. The branch block temporarily blocks pain signals originating from the facet joint.

Although medial branch blocks (MBB) are sometimes called facet joint injections, they are not the same. Typically, physicians perform medial branch block injections as a diagnostic procedure for facet joint pain. 

The article below provides more information on a medial branch block injection, why it is performed, and what to expect from the procedure. 

Where Are the Medial Branch Nerves?

The medial nerves run through the facet joints and carry pain signals from the facet joints to the spine, allowing movement between the vertebrae. The nerve block is placed outside the facet joint near the medial nerve. 

Medial nerves are located in the cervical, thoracic, and lumbar spines. Based on the suspected location of the painful facet joints, the doctor may administer cervical nerve blocks, thoracic injections, or lumbar medial branch block injections. 

Why is a Medial Branch Block Performed? 

Most physicians and insurance companies consider a medial branch injection a diagnostic procedure. This means it helps determine the cause of back or neck pain rather than treating it. 

During the procedure, the nerve block injection temporarily interrupts the nerve signal to the facet joint. If the facet joints are causing the pain, the nerve block will relieve the pain.

Pain relief is measured through patient self-reporting using the Numerical Rating Scales 1 and/or the Patient Global Impression of Change 2.  

Do Medial Branch Block Injections Diagnosis the Cause of Back or Neck Pain?  

Medial branch blocks help diagnose pain in facet joints. The medial nerves supply sensation to the various facet joints. If the facet joints are the cause of the pain, the pain should decrease after the injection. 

Several factors, such as arthritis and trauma, can cause pain in the facet joints. A medial nerve block will not determine the underlying cause of facet joint pain.

Will Medial Branch Nerve Block Injections Relieve Facet Joint Pain? 

The medial nerves are surrounded by a canal formed by soft tissue and bone. Administering an injection into the canal allows the anesthetic to surround the nerve, which blocks pain signals transmitted from the nerve. 

Injecting anesthetic medication into the medial nerve near the facet joint suspected of causing pain may provide pain relief. If the facet joint is not the source of pain, the procedure will likely not reduce pain. But the pain relief is usually temporary.

Are You a Good Candidate for a Medial Branch Block Injection? 

You may be a good candidate if you have back or neck pain symptoms and do not know the exact cause but suspect it is a facet joint. 

There are some exceptions where you may not be an appropriate candidate for a medial nerve block because of an increased risk of complications. A medial block injection may be contraindicated in the following situations: 

• An active systemic infection 
• An infection at the injection site
• A bleeding disorder 
• Pregnancy
• Known allergies to the drugs used in a medical block procedure 

How Do You Prepare for Medial Branch Blocks? 

Prior to a medial nerve block, your doctor will discuss any risks and potential complications. Medial blocks are usually safe. However, with any medical procedure, being aware of possible complications is essential. Your doctor will discuss risks, such as bleeding, swelling at the injection site, and infection. These complications are uncommon. 

You are also provided information on any restrictions before the injection procedure. For instance, your doctor may instruct you to avoid blood thinning medications a few days before the procedure. But do not stop taking medications unless instructed to do so. 

You might be asked to avoid pain medication before having the nerve block. This is to determine whether the injection reduces pain, not the pain medication. 

A medial branch nerve block is done on an outpatient basis. You may need to come in 30 minutes before the injection for preparation. 

Driving is often not recommended after a medial branch block, so arranging for a ride home after the injection is helpful. 

How is a Medial Branch Block Procedure Performed? 

During a medial branch block injection, the steps for the procedure include the following: 

1. The doctor applies a local anesthetic to the skin to decrease discomfort from the needle.
2. Your vitals, such as your blood pressure and heart rate, will likely be monitored before the procedure to ensure there are no concerns. 
3. You are typically positioned on your side or face down to provide the best access for the injection. 
4. With the assistance of fluoroscopy imaging, the doctor injects the anesthetic and possible steroid medication into the medial nerve near the suspected painful facet joint. 
5. After the injection, you spend a period of time being observed for complications before you leave. 
6. You are provided with any instructions on caring for the injection site or watching for complications.

What to Expect After a Medial Branch Nerve Block 

After you have a medial branch nerve block, you can typically expect one of three reactions, including: 

• Pain does not go away: If your pain is not relieved, it may not be due to facet joint problems. 
• Pain resolves for a few hours and returns: This indicates that pain is likely from the facet joints. Your doctor may recommend further treatment. 
• Pain resolves and stays away for several days: If the medial block contains a steroid medication in addition to a local anesthetic, you may get pain relief for a short time. Further treatment for lasting pain relief is likely beneficial. 

Is a Medical Branch Block Right for You? 

A medial nerve block injection is delivered into the medial nerves near the facet joints. It can help temporarily block pain signals from damaged facet joints. 

The procedure helps doctors diagnose whether facet joints are causing the pain. The results can help determine if further long-lasting treatment is needed. 

If you have any questions or would like to schedule a consultation, please contact us today! 

References:

1. Michener, L. A., & Snyder, A. R. (2008). Evaluation of Health-Related Quality of Life in Patients with Shoulder Pain: Are We Doing the Best We Can? Clinics in Sports Medicine, 27(3), 491–505. https://doi.org/10.1016/j.csm.2008.03.001
2. Patient global impression of change scores within the context of a chronic pain rehabilitation program. (2009). The Journal of Pain, 10(4). https://www.jpain.org/article/S1526-5900(09)00269-7/fulltext