doctor holding spine model and pointing on vertebra while patient sitting on the hospital bed next to her with backs turned.

What Is It?

The sacroiliac joint, also called the SI joint, is a large joint in the lower part of the back connecting the hip and the sacrum on either side of the spine. The purpose of the SI joint is to support the upper body. Although the movement of the SI joint is limited, it can become inflamed. Such inflammation can lead to sacroiliac joint dysfunction, causing chronic pain in either the lower back or legs. Injections to relieve pain in the SI joint have been shown to alleviate pain for at least a month per injection.

What to Expect

Although, a local anesthetic will be injected into the area before the injection, you will be awake for the procedure.

After changing into a hospital gown, you will be instructed to lie on the table on your stomach and given a pillow to support your hips. Using technology such as ultrasound or x-ray, and possibly contrast, to locate the area of concern, the doctor will likely numb the area with an injection of Novocain. Anti-inflammatory medication will then be injected to the area of concern.

Once the injection has been administered, your healthcare team may continue to monitor you for any complications before releasing you.

Patients receiving sacroiliac joint injections should notice relief of symptoms almost instantly. Because sacroiliac joint injections are sometimes used diagnostically, it is possible that the injection may not relieve pain, if your SI joint is not the actual source of the problem. Pain relief may also be extended when cortisone is injected for inflammation reduction as well. Risks associated with the procedure include site-area bleeding or tenderness or raised blood glucose levels in diabetic patients.

How to Prepare

On the day of your injection, you will be asked not take any medicine for pain relief (such as Tylenol, Motrin, etc.), though anti-anxiety medication may be given to you to help you relax if needed at your procedure. Because of the location of the injection, it will be advised for you to arrange transportation home from the procedure. Be prepared for the possibility of weakness in your legs following the procedure. Additional treatment or more injections may be required for complete relief.