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Facet Joint Injection

What is a Facet Joint Injection?

A facet joint injection is given to patients who suffer from low back pain and sometimes leg pain which is caused by inflammation or irritation of the facet joints.  Facet joints are the small joints of the spine that help control motion and stability of the spine. Facet joints are found in the neck (cervical region), upper back (thoracic region) and lower back (lumbar region). They can become painful as a result of arthritis, injury or mechanical stress.

Why do I need a Facet Joint Injection?

In general there are two reasons your Doctor has asked that you have a facet block injection

  1. For treatment – the injection can reduce inflammation and offer long lasting pain relief.  This can last from a few weeks to a few months.
  2. For diagnostic purposes – If relief is obtained from the local anaesthetic in the injection then this suggests that the facet joints are the source of the pain and allows for the planning of further management.


A Radiologist will perform the procedure under CT guidance.  The patient will be asked to lie face down on the bed of the CT scanner and the area to be injected will be cleaned using antiseptic solution.  A small needle is placed into the facet joint using the CT scan to check the position of the needle.  Cortisone and local anaesthetic will then be injected into the facet joint. In some cases more than one injection may be necessary.

You may experience some discomfort for a short time until the local anaesthetic has time to work.  The procedure usually takes about 15-30 minutes.

The cortisone component of the injection usually starts to work about 2-3 days after the injection.  The effects of the injection last on average 3-6 months.

Are there any risks or side effects?

There are always risks and/or side effects associated with any treatment/procedure. Overall however, the risks are low but can include:

  • Discomfort at the injection site
  • Mild increase in pain following the injection (probably a temporary pressure effect of the injection)
  • Very rare nerve damage (due to trauma, the medication, infection or bleeding)
  • Allergic reaction to the medication

Post Procedure

  • It is preferable to have someone to drive you home.
  • If initially pain relief occurs, it will be short lived, approximately 4-6 hours. During this time it is very important for you to record how much pain relief you had.
  • If you are given a pain relief chart to fill out, please take time to fill it out and remember to take the completed chart with you when you next see your treating doctor.
  • You may notice some slight bruising and/or soreness at the site of the injection. If required, apply ice to the affected area and take paracetamol (eg. Panadol) to help with relief of these symptoms.
  • There may be an increase in pain and some stiffness at first, however this generally wears off after 48 hours.
  • You should refrain from exercise or strenuous activity for up to one week after the procedure depending on what your Doctor has told you.  Please follow your treating practitioner’s advice on how best to recommence pre-treatment activities.
  • If after 48 hours following your injection you are experiencing any fever, swelling, localised heat or increasing pain, you should contact your Doctor without delay.

Things we need to know from you

Please inform the Radiology staff of any of the following:

  1. If you have allergies to any medication, anaesthetic agent or X-ray contrast
  2. If you are taking any blood thinning medications (Aspirin, Warfarin, Clopidogrel etc)
  3. If you are feeling unwell or need to cancel your appointment please ring our office as soon as possible on (08) 8229 210

Note to female patients: If you are pregnant, or suspect you may be, or if you are breast feeding please advise us before your appointment.

Important things you must bring to your appointment

  • A referral from your Doctor
  • Medicare card
  • Pension/Concession card
  • Any previous films/x-rays
  • WorkCover/Motor Vehicle Accident claim details (if applicable) i.e. claim number, name of employer or insurer


Please feel free to contact our staff at any time if you have any questions or concerns on (08) 8229 2100