A sacroiliac joint injection is designed to diagnose and treat pain and inflammation from sacroiliac joint dysfunction.

Either too much or too little movement in one of the sacroiliac joints, which are located at the bottom of the spine on each side of the sacrum, can cause lower back pain and/or leg pain.

An injection in the sacroiliac joint usually has two goals: to confirm the sacroiliac joint as the source of the pain, and to alleviate that pain.

The procedure begins with the patient lying on his or her stomach. The area around the sacroiliac joint is numbed with an injection of a local anesthetic.

Then, using fluoroscopy dye and X-rays to assist in guiding the injection, a needle is inserted into the sacroiliac joint to deliver medicine directly to the source of pain.

The medication injected into the joint can be a local anesthetic, such as lidocaine or bupivacaine, and may also include an anti-inflammatory medication, such as a corticosteroid. If the local anesthetic provides immediate pain relief, it diagnoses the sacroiliac joint as the source of the patient’s pain.

The anti-inflammatory steroid may relieve pain in the sacroiliac joint over a longer period of time, possibly for weeks or months, allowing the patient to pursue physical therapy.