Medial branch blocks (Imaging) | North Bristol NHS Trust

What is a medial branch block?

This procedure is for diagnosis only and is not for permanent pain relief. Your pain is likely to return a few hours after the procedure.

Facet joints are found between each of the spinal bones and allow the spine to move. The medial branches are nerves that carry information, including pain, from the facet joints to the brain. Sometimes back pain arises from these joints.

A medial branch block uses local anaesthetic to numb these small nerves.

If the pain is coming from the joints the pain may be reduced for some hours following these injections.

Following this procedure we can determine whether the facet joints are the cause of your pain.

Depending on the results, your consultant may offer a longer-lasting treatment that could be done after your follow up call or visit.

How do I prepare for the medial branch blocks?

We would advise you not to take any pain relief medication for 6 hours before your appointment. This is so we can accurately assess if the local anaesthetic changes your back pain. You can eat and drink on the day as normal. You are advised not to drive following the procedure.

Please tell us before attending for the procedure if you take any blood thinning medication such as:

Warfarin.
Clopidogrel.
Rivaroxaban.
Dipyridamole.
Dabigatran.

Please note this list is not exhaustive.

The number for the Imaging department is on your appointment letter.

What will happen during the procedure?

You will arrive at Gate 18 where a member of the Imaging team will take you through to the fluoroscopy waiting room.
Following confirmation of your details and history you will be shown into the X-ray room and introduced to the staff performing the procedure.
You will be cared for by a small team including a radiologist (X-ray doctor) and/or radiographer and an imaging support worker.
Before the examination begins the radiologist or specialist radiographer will explain what they are going to do. You will be given the opportunity to ask any questions you may have. If you are happy to proceed you will be asked to sign a consent form. We will also ask you to score you back pain out of 10 before we begin.
You will then be asked to lie on your front on the X-ray couch. The skin will be cleaned and a small amount of local anaesthetic will be injected under the skin. This stings for a few seconds and the area then goes numb.
A very fine needle will be directed to the medial branches using the X-ray machine.
When the radiologist or specialist radiographer is satisfied with the needle position, the local anaesthetic will be injected. Following the procedure we will ask you again to score your pain out of 10.
Afterwards you will be asked to sit in our waiting room for 20 - 30 minutes so that we can ensure you are feeling well before you go home.

Will it hurt?

You may have some discomfort during the procedure. If you feel uncomfortable, let one of the members of the team know and they will try to make you more comfortable.

How long will it take?

You will be awake throughout the procedure, which lasts about 15 – 30 minutes.

How will I feel after the injections?

Remember that medial branch blocks are not a treatment. They are done to help us diagnose the source of your pain.
Immediately after the injections you may feel less pain but it will probably return after a few hours.

Are there any risks or side effects?

Generally it is a very safe procedure, but as with any treatment there are risks or side effects:

An increase in your pain in the first 24 hours following injection. Should this occur, take your usual or prescribed pain medication and seek advice from your pharmacist or GP if necessary.
Bleeding or haematoma (a bruise under the skin) – this should settle down by itself.
Infection developing at the injection site. This will happen to less than 1 in 5000 people. Contact your GP if you experience any redness or tenderness at the injection site.
The procedure is performed under X-ray to confirm the needle is in the correct place. Patients who are or may be pregnant should inform the department before attending their appointment.

Who should I contact if I have any concerns?

If you have any concerns please contact the Imaging Department using the number on your appointment letter.