SI Joint Injection
The sacroiliac (SI) joint is a large, weight-bearing joint connecting the sacrum to the pelvis. SI joint dysfunction is a frequently overlooked cause of low back, buttock, and sometimes leg pain — estimated to be responsible for 15–25% of chronic low back pain cases.
An SI joint injection delivers anti-inflammatory steroid medication directly into the SI joint space to reduce inflammation and provide diagnostic and therapeutic relief.
Recognizing SI Joint Pain
SI joint pain typically presents as:
- One-sided low back or buttock pain
- Pain that may radiate into the groin, hip, or posterior thigh
- Worsening with prolonged sitting, stair climbing, or rolling in bed
- Point tenderness directly over the SI joint (just medial to the posterior iliac spine)
- Positive provocation tests on physical examination (FABER, Gaenslen's, thigh thrust)
The Procedure
Under fluoroscopic guidance, Dr. Rubin places a needle into the SI joint — a narrow, irregular joint that requires imaging guidance to access reliably. After contrast confirms intra-articular placement, steroid and local anesthetic are injected.
The procedure takes approximately 15–20 minutes. Many patients notice immediate pain reduction from the local anesthetic component.
Diagnostic Value
Like medial branch blocks, the SI joint injection serves dual purposes. If your pain significantly decreases after the injection — particularly in the first 1–2 hours when the local anesthetic is active — this confirms the SI joint as a pain generator. This information guides future treatment decisions, including potential SI joint fusion if temporary relief is insufficient.
Expected Relief
Relief typically lasts 1–6 months. A series of up to three injections per year may be appropriate. For patients who respond well but have limited duration of relief, minimally invasive SI joint fusion offers a more permanent solution.
Contact Us
Call 516-492-3100 to schedule an SI joint injection evaluation.