MBB FAQ:

What is a medial branch block?

A medial branch block is a diagnostic injection that places a small amount of local anesthetic (numbing medication) on the small nerves — called medial branches — that carry pain signals from the facet joints in your spine. If your pain temporarily goes away after the injection, it helps confirm the facet joint as the source of your pain. It's a non-surgical, outpatient procedure done under X-ray guidance, typically taking 15-30 minutes with no sedation required.

Why would I need this procedure?

Medial branch blocks are most often used to confirm the facet joints as the source of your pain before moving to a longer-lasting treatment. In some cases — particularly during the workup of more complex or difficult-to-diagnose pain — they're also used to help rule out the facet joints as the cause, guiding you and your physician toward the right next step.

What happens after the block?

If two separate medial branch blocks both provide significant, concordant relief, this confirms the facet joint as your pain generator and you're a candidate for a more definitive treatment. Most patients move forward with radiofrequency ablation (RFA), which offers longer-lasting relief by disabling the nerve. Other options — including cryoneurolysis, regenerative procedures such as PRP, and neuromodulation — are also available for select patients. These advanced treatments are discussed in more detail elsewhere, and your physician will review which option fits your specific situation.

What medication is used?

A small amount of local anesthetic is used to numb the nerve. Because this is primarily a diagnostic procedure, steroid is not used.

What are the benefits?

- Confirms or rules out the facet joints as your source of pain

- Helps guide the right next treatment, avoiding unnecessary procedures

- Minimal downtime

- Identifies the best candidates for RFA and other definitive treatments

What are the risks?

Common and temporary: soreness at the injection site, or temporary numbness near the treated area.

Rare but serious: infection, bleeding, allergic reaction, or nerve irritation. These risks are minimized through X-ray guidance and careful technique.

What are my alternatives?

Physical therapy, oral medication, activity modification, further diagnostic workup, observation, or declining the procedure.

When should I call the office immediately?

Call right away if you experience fever, signs of infection at the injection site, severe or worsening pain, or new weakness or numbness.

Where can I learn more?

Visit our Services page for more on what to expect and how we tailor treatment to you: https://www.osso.health/services

Safety guidance adapted from the International Pain and Spine Intervention Society (IPSIS), 2025.