Sacroiliac Joint Injections (PRP or CSI)

You have two sacroiliac joints, one on each side of your lower back, located where your sacrum meets your hip bones (ilium). These joints absorb the shock between your upper body and your legs. When they become inflamed due to arthritis, trauma, or pregnancy, they can cause intense pain in the lower back, buttocks, and down the legs.

Corticosteroid Injections (CSI) are excellent for quickly putting out the “fire” of acute inflammation and providing fast pain relief. Platelet-Rich Plasma (PRP) is a regenerative option that utilizes your body’s own growth factors to heal damaged ligaments and cartilage inside the SI joint over time, offering a more natural, long-term healing process.

If you have pain that radiates from your lower back into your buttocks or upper thighs, especially when standing up from a seated position or climbing stairs, the SI joint may be the culprit. Your doctor will perform specific physical tests and may use this injection to confirm the diagnosis.

You will lie face down while the doctor numbs the area with a local anesthetic. Using fluoroscopy (continuous X-ray), the doctor carefully guides a needle directly into the SI joint. Contrast dye is often used to ensure precise placement before the steroid or PRP is injected.

This is a quick outpatient procedure. You may experience temporary numbness or weakness in your leg from the local anesthetic, which wears off in a few hours. Patients are usually advised to rest for a day or two before gradually returning to normal activities as the medication takes effect.