CT-Guided Sacroiliac (SI) Joint Injection

With the guidance of CT (a computerized x-ray imaging machine), the physician directs a needle through the skin and into the SI joint. Fluoroscopy allows the physician to view the needle in real-time on the CT monitor to ensure the needle goes directly into the desired area. Contrast may be injected to confirm the correct needle location. When the needle is correctly positioned, the anesthetic and corticosteroid medications are injected into the SI joint to alleviate your pain.

Before the procedure, a clinical staff member will bring you into the CT procedure room. Depending on the type of exam you may be asked to change your clothes into shorts or a gown. Your doctor will greet you, review the procedure, and ask you to sign consent for the exam. Your doctor will address any concerns or questions you may have at this time.

During the procedure, you will be positioned on the procedure table, in the appropriate position for the type of exam you are having. The SI joint is precisely localized by advancing the needle under CT image guidance and confirmed with a test injection of contrast material. The area will be cleaned, and a local anesthetic will be given to reduce discomfort during the procedure. This will be a pinch sensation and some slight burning then the area will be numb. The doctor will then inject the area with medication to reduce the pain and inflammation. A small band-aid will cover the area.

After the procedure, keep the area clean and dry for the next 24 hours, if needed change the band-aid. Generally speaking, the numbing medicine will wear off in 1-2 hours and you may experience your normal pain or slightly more until the medication takes effect. You can expect a small bruise around the area that was injected.

There are things you can do to make your experience more comfortable, and many of these will depend on your individual preferences. You might like to keep a list of questions or — as you’re doing now — educate yourself about the procedure.

Some other things to keep in mind when planning for this procedure include:

• You will need a driver to bring you and take you home
• Your doctor may ask you to stop taking aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or blood thinners (such as Coumadin or warfarin) for a time before the procedure
• If there’s any chance you may be pregnant, tell the technologist or physician
• When you arrive, make sure the doctor knows about any allergies you may have, especially allergies to local anesthetics, such as lidocaine
• Take a bath or shower before you come in for the procedure and do not apply lotions, perfumes, or deodorants

On the day of your procedure you should:

• Wear comfortable, loose-fitting clothes
• Avoid bringing jewelry or valuables
• Be sure you have someone to take you to and from the appointment

The benefits of a CT-Guided SI Joint Injection could be:

• Relief of pain
• Reduced inflammation which may lead to healing

Some risks you should be aware of include:

• As with any procedure, there is a slight risk of infection
• Rarely, this procedure can cause a temporary increase in pain
• Rarely there are reactions to the medication such as rash or hot flashes
• There is a slight risk of nerve damage at the injection site
• There is a slight risk of bleeding

Keep in mind that this information is general. Your radiologist is the best source of information about how these risks and benefits may apply to you.