Lumbar Medial Branch Block

What is a Lumbar Medial Branch Block?

A Lumbar Medial Branch Block, sometimes referred to as ‘facet injection”, is an injection used to help find out if the small facet joints in your lower back are the source of your pain. The function of the medial branch nerves is to carry pain signals from the facet joints – small joints that connect the bones of your spine. If numbing these nerves improves or resolves your back pain, that suggests your pain is (at least in part) coming from the facet joints.

 How do you prepare for a Lumbar Medial Branch Block?

• Talk to your doctor about all medicines you take, especially blood thinners, since you may need to stop them before the injection.
• Don’t eat or drink for a few hours before the procedure (your doctor will give you specific instructions).
• Arrange for a ride home — you may have numbness or weakness in your legs for a few hours after the procedure so it’s not safe to drive.
• Wear comfortable clothing.

Why is a Lumbar Medial Branch Block performed?

• To diagnose the cause of back pain — if the injection relieves your pain, it means the facet joints are likely the problem.
• To provide temporary pain relief (therapeutic aspect)
• To help decide if you may benefit from another procedure called radiofrequency ablation (RFA), which can give longer-lasting relief.

 What can you expect during a Lumbar Medial Branch Block?

• You’ll lie on your stomach, and the skin on your back will be cleaned.
• The doctor uses X-ray guidance (fluoroscopy) to place the needle in the correct spot.
• A small amount of numbing medicine, sometimes combined with a steroid, is injected around the medial branch nerves.
• The procedure usually takes 20-30 minutes.
• You may feel pressure or mild discomfort during the injection.

 What is the follow-up like for a Lumbar Medial Branch Block?

• You’ll be watched for a short time after the injection to make sure you’re okay.
• You should track your pain relief — note how much pain goes away and for how long. This information helps your doctor plan the next step.
• You may feel sore at the injection site for a day or two.
• Most people can return to normal activities the next day.

What are the potential risks for a Lumbar Medial Branch Block?

• Risks are low, but possible side effects include:
• Temporary soreness, bruising, or swelling at the injection site.
• Transient numbness or weakness in the legs.
• Very rare but serious risks: bleeding, infection, allergic reaction, nerve injury, spinal cord injury.

Are there related tests to a Lumbar Medial Branch Block?

• Imaging tests (like MRI or CT scans) may be done before to rule out other causes of back pain.
• If the block works, your doctor may recommend radiofrequency ablation (RFA) for longer-lasting relief.
• Other injections (such as epidural steroid injections) may also be considered depending on your symptoms.