What is the Difference Between Medial Branch Block and Facet Joint Injection

Medial branch block and facet joint injection are two different types of injections used to treat back pain. These injections are often effective in treating pain symptoms. Both these injections consist of similar local anaesthetic and steroid.

The key difference between medial branch block and facet joint injection is their target area. Medial branch block is injected outside the joint space near the medial branch nerve, while facet joint injection is directly injected into the spinal joint.

1. Overview and Key Difference
2. What is Medial Branch Block
3. What is Facet Joint Injection
4. Similarities – Medial Branch Block and Facet Joint Injection
5. Medial Branch Block vs Facet Joint Injection in Tabular Form
6. Summary – Medial Branch Block vs Facet Joint Injection
7. FAQ – Medial Branch Block and Facet Joint Injection

What is Medial Branch Block?

Medial branch block aims to treat pain arising from facet joints in the spine. It targets the medial branch nerves that carry pain signals from the facet joints. Medial branch nerves provide rich innervation to the facet joints. All joint segments below C2-C3 normally receive medial branch innervation from two levels. Therefore, injecting medial branch block near the medial branch nerves may suppress the nerve from sending pain signals to the brain. It can block specific fibers called C fibers within the nerve, which results in a decrease in pain transmitted to the brain and a decrease in the permeability of nerve fibers to receive blood, which decreases pain transmission.

Figure 01: Medial Branch Block

Studies show that about 60-70% of patients experience major pain reduction after this procedure. However, medial branch block injections generally cause mild and temporary localized side effects, such as pain and soreness, numbness, weakness in the arms or legs, bleeding or bruising, and vasovagal reactions.

Facet joint injection is administered directly into the facet joint to treat pain arising from facet joints in the spine. Facet joints are enclosed within a joint capsule made of synovial membrane tissue. If this tissue becomes inflamed, facet joint injections can help reduce the inflammation. These injections inhibit the production of inflammatory chemicals and reduce pain, making pain receptors less sensitive.

Figure 02: Facet Joint Injection

Facet joint injections have a 75% success rate. Furthermore, the potential risks and complications of facet joint injections are infection, allergic reaction to drugs or contrast dye, nerve damage, spinal cord injury or paralysis, excessive bleeding, bruising, and vasovagal reactions such as dizziness, nausea, and flushing.

Medial branch block and facet joint injection aim to treat pain arising from facet joints in the spine.
Both injections consist of local anesthetic and steroids.
These injections have a higher success rate.
Both injections have risks and potential complications.

Definition

Medial branch block is a medical procedure aimed at treating pain originating from the facet joints in the spine by targeting the medial branch nerves, which are responsible for transmitting pain signals from the facet joints.
Facet joint injection is a medical procedure aimed at treating pain from the facet joints in the spine by directly targeting and injecting into the facet joints themselves.

Effect

Medial branch block can suppress the nerve from sending pain signals to the brain, block certain fibers within the nerve that results in a decrease in pain transmitted to the brain and decrease the permeability of nerve fibers to receive blood which decrease the pain transmission.
Facet joint injection may inhibit the production of inflammatory chemicals which reducing pain and they also make pain receptors less sensitive.

Success Rate

Medial branch blocks have a 60-70% success rate.
Facet joint injections have a 75% success rate.

Risks and Complications

The potential risks and complications of medial branch block are pain and soreness, numbness, weakness in the arms or legs, bleeding or bruising, and vasovagal reactions such as dizziness, nausea, and flushing.
The potential risks and complications of facet joint injections are infection, allergic reaction to drugs or contrast dye, nerve damage, spinal cord injury or paralysis, excessive bleeding and bruising, and vasovagal reactions such as dizziness, nausea, and flushing.

The following table summarizes the difference between medial branch block and facet joint injection.

Summary – Medial Branch Block vs Facet Joint Injection

Medial branch block and facet joint injection aim to treat pain arising from facet joints in the spine or back pain. However, the medial branch block is injected outside the joint space, near the nerve called the medial branch nerve, while the facet joint injection is injected directly into the spinal joint. This is the key difference between medial branch block and facet joint injection.

1. What is the main cause of back pain?

The main cause of back pain is injury to a muscle or ligament. These strains and sprains can occur due to many reasons, such as improper lifting, poor posture, and lack of regular exercise. Being overweight may also increase the risk of back strains.

2. Which drug is best for back pain?

NSAIDs are often used to treat back pain. They can be purchased over the counter. Examples are ibuprofen and naproxen. NSAIDs help reduce pain, swelling, and inflammation in muscles and around damaged spinal discs or arthritic joints.

3. How long should a medial branch nerve block last?

The medial branch block targets the medial branch nerves that carry pain signals from the facet joints. The back pain relief from the medial branch block is only intended to last approximately 8 hours.

4. How successful are medial branch blocks?

More than half of the patients experience at least 60-70% improvement in pain after a successful diagnostic medial branch block near medial branch nerves that carry pain signals from the facet joints.

5. What is the success rate of facet joint steroid injections?

Facet joint injections combine a fast-acting anesthetic for immediate pain relief and a slow-release corticosteroid to reduce inflammation over time. When a patient gets this injection at the right area, facet joint injections have a 75% success rate.

Reference:

1. Yash Mehta, DO. “Medial Branch Nerve Blocks.” Spine.
2. “What next If Facet Joint Injections Don’t Work?” Vanguard Spine & Sport.

Image Courtesy:

1. “Pain-Doctor-Medial-Branch-Block-3” By PainDoctorUSA – Own work (CC BY-SA 4.0) via Commons Wikimedia

2. “Blausen 0391 FacetJointInjection” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia

CONTENTS

What is Medial Branch Block?

What is Facet Joint Injection?

Similarities Between Medial Branch Block and Facet Joint Injection