What is a medial branch block?

Medial branch nerves carry pain signals to the brain from joints within the spine. These joints, known as facet joints, connect the bones of the spine and allow it to twist and bend, without it moving too far out of place. A medial branch block is a procedure where local anaesthetic and steroids are injected close to the medial nerves connected to a certain facet joint of the spine. In a typical procedure, injections are made at nerve sites of several levels of the spine’s joints.

What is the purpose of a medial branch block?

Doctors use medial branch blocks as both a diagnostic and therapeutic tool in relieving back pain.

Should the injection provide immediate pain relief, this confirms that the problem area is indeed the facet joint or joints in question. However, in the case that the medial branch block provides no pain relief, facet joint problems can be ruled out and further tests and examinations can be made to determine the true cause.

In some patients, the pain may subside temporarily but later return as strong as before. This demonstrates that the facet joint is causing the problem but the steroid was ineffective in sustaining the initial pain relief provided by the anaesthetic. In this case the medial branch block acts merely as a diagnostic tool and an alternative pain-relief method will need to be employed.

For other patients, their pain disappears with the effects of the anaesthetic and returns at a far lower strength and shows improvement over the following days. This indicates that the steroid has been effective in relieving pain and may mean that the treatment is repeated as necessary for its therapeutic value.

Patients whose pain is somewhat reduced by performing a medial branch block may also benefit from radiofrequency lesioning, which can provide longer term relief.

Who may need a medial branch block?

Patients with back pain suspected to be related to one or more facet joints of the spine are likely to be recommended for a medial branch block primarily in its diagnostic capacity. However, it may also be of therapeutic benefit if the steroid is effective in relieving the pain.

In any case, medial branch blocks can provide doctors with important information about how best to treat back pain in each individual.

How are medial branch blocks administered?

During the procedure, patients lie on their stomach to allow the doctor easy access to the affected area. A numbing agent is used on the skin to reduce sensation and the injection of anaesthetic and steroids is inserted at the medial branch nerve.

The doctor uses X-ray guidance to ensure the injection is correctly placed and may also inject a coloured dye before administering the anaesthetic and steroid preparation to ensure that the affected area will be fully covered.

Is it a safe procedure?

Serious complications of medial branch blocks are extremely rare. Some patients experience pain or discomfort at the injection site for several days after the procedure. The risk of nerve damage or bleeding is minimised by the doctor’s use of X-ray imaging to guarantee precision.

What type of doctor performs a medial branch block?

A range of specialists may offer a medial branch block to treat back pain including neurosurgeons, rheumatologists, as well as orthopaedic, osteopathic and pain medicine specialists.