What is an SI Joint Injection?


This injection is an injection of local anaesthetic and/or steroid into and around the Sacroiliac joint. These are small joints where your pelvis and sacrum join. This is an interventional procedure. There is no specific preparation and you may eat and drink as normal before and after the procedure.

Please read and sign this form so that we can be sure you understand the risks and complications potentially associated with this procedure. Please inform the booking staff if you are on Warfarin, Plavix, or any other blood thinning agents, or have any other medication allergies.

SI Joint Injection

What happens during an SI Joint Injection?

A. Before your scan

What to bring

  • Your request form
  • Any relevant previous imaging
  • Your Medicare card and any concession cards

Preparation – In the week before your scan

You must advise us of any blood-thinning medication your are taking such as Aspirin, Warfarin, Plavix or Iscover and stop taking it for a period of time before your treatment. Please contact us for advice.

Preparation – On the day of the scan

You will be asked to fill out a questionnaire regarding your health status, medication, and any known allergies. If there is any chance you may be pregnant, please inform us before your scan. You may also be asked to change into a gown and remove some jewellery for your scan.

B. During your SI Joint Injection


When you are transferred to the CT room you will be made comfortable on the examination table. The examination table slides you into the centre of the CT machine and some preliminary pictures are taken to confirm the scan position.

The skin will be washed with antiseptic and a local anaesthetic will be injected. A fine needle is then inserted, guided into position using CT control and an injection will be given into the sacroiliac joint in your lower back.

Your procedure will take about 20 minutes.

Risks and side effects

CT-guided SI Joint Injection is a very low risk procedure. Find out about CT Risks and Side Effects.

Other risks associated with this procedure include:

  • Pain or discomfort at the needle insertion site, or bruising after the procedure.
  • Temporary numbness or a tingling sensation can sometimes occur.
  • Inflammation which may involve redness or swelling and increased pain after 48 hours.
  • Increasing back pain needs to be promptly reported to your referring doctor.

Any medical procedure can potentially be associated with unpredictable risks.

Who will perform my SI Joint Injection?

Our specialist medical imaging team will perform your SI Joint Injection.

SI Joint Injection

What happens after an SI Joint Injection?

How do I get my results?

After your appointment, the information from your scan is processed and interpreted by Envision’s medical imaging team before delivery of a report to your doctor.

Post-procedural information

At the end of the procedure the needle will be withdrawn carefully from the insertion point and a band aid applied.

Pain relief can take a few days to occur so you may need to continue with your current medication for a short time. We ask that you rest your lower back and avoid any strenuous activity.

SI Joint Injection

Download an Information and Consent Form