The Kent Centre for Pain Medicine and Neuromodulation: Medial branch blocks

You have been referred to the Pain Clinic for medial branch blocks. This leaflet will explain:

• what a medial branch block is

• how a medial branch block can help with chronic pain relief

• what the side effects could be, and

• what will happen during and after the procedure.

If you have any questions after reading this leaflet, please speak to your GP or other relevant healthcare professional.

What are facet joints and medial branch nerves?

Medial branch nerves are very small nerves, that allow you to feel pain from facet joints. These nerves do not control any muscles or feeling in your arms or legs. They are found along a bony groove in your lower back, neck, and over a bone in your mid-back. These nerves carry the pain signals to your spinal cord, which eventually reach your brain, where the pain is noticed.

What is a medial branch block?

A medial branch block is a procedure where pain-blocking medicine is injected around a specific facet joint. This temporarily prevents the pain signal from being carried by the medial branch nerves that supply this facet joint.

How will medial branch blocks help?

Medial branch blocks may be used to see whether your pain started from particular facet joints. These blocks are not a cure, but may temporarily reduce your pain.

The outcome of this treatment will be one of the following.

1. The pain does not go away at all. This means that the pain is probably not coming from your facet joints. This result can help diagnose your problem and guide us with any future treatment.

2. The pain goes away for a few hours or days, but comes back and does not improve. This result can help diagnose your problem and guide us with any future treatment. The pain is probably coming from your joints, but the steroid did not benefit your joints.

3. The pain goes away after the block. Your pain may even come back after a day or two, but gets better over the next week or so. This means that the block was of therapeutic value; the steroid had a long-lasting effect on your pain.

What happens during my procedure?

Medial branch blocks are carried out as a day case procedure, so you can go home on the same day.

The procedure is performed in Day Surgery to minimise your risk of getting an infection. Shortly before your procedure we will ask you to change into a theatre gown.

The procedure

• The procedure is carried out under x-ray guidance. This allows your doctor to inject you in the correct position. You must tell your consultant if there is any chance that you may be pregnant, as x-rays may harm your baby.

• We will ask you to lie down on your front. Your doctor will clean the area with an antiseptic solution. This can feel cold.

• A local anaesthetic is injected at the site of the procedure. This may sting to start with, before your skin goes numb.

• You must keep still during your procedure, as a special hollow needle will be carefully inserted under x-ray guidance into the correct position. A preparation of steroid and a local anaesthetic are injected; this may reduce inflammation and pain.

• The above may be repeated at different levels on your spine.

What are the possible side effects?

• There may be some pain, bruising, and / or bleeding at the needle site.

• You may feel a little unsteady when you first stand.

• The injection may make your pain worse. This should settle within one month.

• There is a small risk of infection at the site of your injections. This may need antibiotic treatment. Contact your GP or call NHS 111 if:

  • there is warmth, redness, or tenderness at your injection sites, or

  • you feel hot and unwell.

• You may have some leg weakness or numbness, which should settle within a few hours. If this happens you may have to stay in Day Surgery until this goes away.

• Diabetics may have raised blood sugar levels in the short-term.

What will happen after my injections?

• A small dressing will cover the injection sites. You can remove this dressing after 24 hours. Do not worry if it falls off sooner.

• You will be discharged home 1 to 2 hours after your procedure.

• You must not drive for 24 hours following your procedure. Please arrange for someone to drive you home from the hospital. We also strongly recommend that you have someone stay at home with you until the following day.

• Start your normal activities as soon as possible. However, do not do any strenuous activities for at least one day after your injections.

• You may notice an immediate improvement, but this improvement can be delayed for a few days. Sometimes there may be a slight increase in pain for 24 to 48 hours. Steroids work slowly, so even if your procedure has worked well, nothing may seem to happen for several days.

Will I need a follow-up appointment?

You will be contacted by telephone in 6 to 8 weeks for a follow-up appointment.

Further information

If you have any concerns about the information in this leaflet or your procedure, please phone the Pain Clinic.

Kent Centre for Pain Medicine and Neuromodulation (direct lines)

• Kent and Canterbury Hospital, Canterbury
  Telephone: 01227 783049

• Queen Elizabeth the Queen Mother (QEQM) Hospital, Margate
  Telephone: 01843 235094

• William Harvey Hospital, Ashford
  Telephone: 01233 616691

Useful information

• East Kent Hospitals. Chronic pain patient information

• Faculty of Pain Medicine of the Royal College of Anaesthetists. Information for adult patients undergoing: Facet Joint Medial Branch Blocks for the Treatment of Pain.