Medial Branch Blocks and Facet Joint Injections

What Is It?

Facet joints are small joints at the back of the spine that provide stability and help guide motion. They are found in the neck (cervical), upper back (thoracic) and lower back (lumbar). They can become painful as a result of arthritis, injury or mechanical stress. Facet Joints may become painful as a result of arthritis or injury. The Medial Branches supplying these joints can be injected with a local anaesthetic. The reasons for doing this include diagnosis and therapy.

How long does it last?

The length of effect for diagnostic injections is between 6 and 12 hours. Longer lasting relief may be achieved with the addition of a corticosteroid (days to months).

Will I Be Awake and Is It Painful?

Sedation is a popular option that is offered, it can reduce the stress and discomfort of the procedure. An alternative to sedation is receiving a local anaesthetic to numb the area during the procedure, it is imporant to note you may feel an amount of discomfort during the procedure, and after the numbing injection wears off.


You should notify the specialists if you are: taking blood thinners; diabetic; pregnant; allergic; or unwell. Before the procedure, you should: avoid eating for 6 hours; continue to drink clear liquids until 3 hours prior; arrange for a family member or friend to accompany you.

What Happens After?

You will be placed in a recovery area for up to 90 minutes and are required to have someone with you overnight. For 24 hours you should refrain from driving, alcohol, machinery and important decisions. When you wash, you are required to take the dressing off.

What does the procedure involve?

The procedure involves: Changing into a hospital gown; Speaking to an anaesthetist if you are having sedation; You may have a small cannula inserted; Your heart rate, oxygen levels and blood pressure will be monitored throughout the procedure; The skin over the area to be injected will be cleaned.; Local anaesthetic will be injected into your skin.; Using an x-ray machine, a needle will be guided toward the target. If necessary, x-ray dye may be used to confirm the needle is in the correct position. Prior to the needle tip being heated, further local anaesthetic will be injected. The temperature of the tip of the needle is raised and if required, multiple injections will be used. A final injection of anaesthetic and steroid may be administered. Generally the procedure takes between 15-30 minutes.

Potential Complications

Pain or discomfort at the site of injection; A pain flare; Infection; Bruising; Muscle weakness; Bleeding; Allergic reactions; Failure of the procedure to reduce pain; Temporary nerve damage; Side effects caused by steroids can include transient flushing, mood swings, high blood sugar levels (especially in diabetic patients).


It is vital that you are fully informed of the procedure, what is involved, potential risks and side effects. You will be asked to sign a consent form. If you have any questions or concerns, please discuss these with your specialist. This form states you understand the potential benefits, risks, alternatives and what will occur if you do not go ahead with the procedure. You are free to withdraw consent at any stage up until the start of the procedure.