Medial branch blocks

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?

There is no preparation for this procedure. You can eat and drink on the day as normal. You are advised not to drive for that day.

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.

What will happen during the procedure?

You will be shown to a cubicle in one of the medi-rooms where you may be asked to change in to a gown, if you need assistance please ask. The nurse will ask you some questions and record your observations. You will be taken to the room where your procedure will be performed under x-ray.

The doctor will explain the procedure and ask you to sign a consent form. You will be asked to lie on your front on the X-ray trolley. The skin around the site of the injection will be cleaned and you will be given a local anaesthetic. The number of injections will depend on your symptoms.

Will it hurt?

You may have some discomfort during the procedure. If you feel uncomfortable, let the doctor or nurse 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.

What happens after my injections?

After your injections you will be taken back to the medi-room, where a nurse will check and record your observations. You will be able to have something to eat and drink and then you can go home. You will have a small dressing on the area that has been treated that you can take off later that day.

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. The doctor will discuss these more fully with you before you sign your consent form.

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.

What should I look out for when I go home?

Anyone having an injection is at risk of infection. This is very rare but some of the signs of infection include:

  • Redness, swelling and heat around the injection site
  • Increased temperature
  • Generally feeling unwell

Increase in pain

  • It is not unusual for your pain to worsen temporarily, but it can also remain the same
  • Take your painkillers as normal
  • Apply heat/cold to the affected area
  • Try to keep active

Who should I contact if I have any concerns?

If you have any concerns please contact the Pain Clinic on: 0117 414 7380 (Monday to Friday, 9.00am - 5.00pm).

Please contact your GP at any other time.

If you or the individual you are caring for need support reading this leaflet please ask a member of staff for advice.

How to contact us:

Pain Clinic
Gloucester House
Southmead Hospital
BS10 5NB

0117 4147361

© North Bristol NHS Trust. This edition published July 2021. Review due July 2023. NBT002952

Medial branch blocks