The Kent Centre for Pain Medicine and Neuromodulation: Medial branch blocks (fast-track denervation pathway)

You have been referred to the Pain Clinic for medial branch blocks, on the fast-track denervation pathway. 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. The nerve block 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.

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.

Should I continue to take my prescribed pain-relieving medication?

Yes. If you are not currently taking anything for pain relief, take pain-relieving tablets such as paracetamol, if needed.

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.

Will I need a follow-up appointment?

A telephone appointment will be made for a nurse to call you. You will be told the date and time of this appointment after your procedure.

At this appointment the nurse will need to know how much your pain has been reduced. For example:

Pain has gone 100% - 75% - 50% - 25% - 0% Pain not changed

The nurse will also need to know how long any pain relief from this procedure lasted. For example:

• no pain relief

• a few hours of pain relief

• one or two days of pain relief

• your pain relief continues.

You may find it helpful to complete this pain diary after your procedure. It will help you answer the nurse’s questions during your follow-up appointment. It will also help the Pain team assess how well the injection has worked.

(0 = pain not changed, 100 = pain has gone completely)

During your appointment, the nurse will review the outcome of your procedure and plan what happens next.

What happens next?

This depends whether this treatment has offered you any pain relief that was thought to be significant by you and your doctor / nurse. If it did, you will be offered another procedure called radiofrequency denervation of the facet joints.

Pain relief from radiofrequency treatment can last much longer than injections. If the pain relief you had from the medial branch blocks was good, the chances are that radiofrequency treatment will work as well. This cannot be guaranteed.

Radiofrequency treatment will be carried out within 4 to 6 weeks of the medial branch blocks.

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.