Sacroiliac Joint Injection
A sacroiliac (SI) joint injection is a minimally invasive procedure in which a steroid medication and/or local anesthetic is injected into or around the sacroiliac joint. The sacroiliac joints (SI) are paired structures (on the right and left) that connect the spine to the pelvis and allow for motion. Occasionally, the SI joint motion unit can become dysfunctional (for a variety of reasons), causing pain.
The injection is used to reduce inflammation and relieve pain in the lower back, buttocks, or legs that may be caused by SI joint dysfunction, inflammation (sacroiliitis), or degenerative joint disease. In some cases, it is also used diagnostically to confirm that the SI joint is the source of pain.
Who Benefits from Sacroiliac Injections?
You may be a candidate for an SI joint injection if you experience:
- Lower back pain that is off to one side, near the beltline
- Pain that radiates into the buttocks, hips, or thighs
- Discomfort while standing, walking, or climbing stairs
- Increased pain with prolonged sitting or transitions (e.g., sitting to standing)
- Tenderness over the SI joint area when pressed
- Poor response to physical therapy, NSAIDs, or other conservative treatments
SI joint dysfunction can result from injury, arthritis, pregnancy-related changes, or biomechanical stress.
What to Expect
SI joint pain may originate from within the joint itself or from surrounding structures, such as the SI ligament. An SI joint injection may be given around the joint—periarticular injection or within the joint—intra-articular injection.
- Preparation: You’ll be asked to lie on your stomach. The skin over the injection site is cleaned and sterilized.
- Anesthesia: A local anesthetic will numb the area. Sedation may be used in some cases.
- Guidance: The physician uses fluoroscopy (X-ray) or ultrasound to precisely guide the needle into or around the SI joint.
- Injection: A mixture of corticosteroid and local anesthetic is injected to reduce inflammation and pain.
- Duration: The procedure typically takes 20–30 minutes.
After the injection, you will be monitored briefly and may be asked to reproduce the pain and assess the response before being released.
After the Procedure
- Immediate Relief: If a local anesthetic is used, you may feel temporary pain relief within minutes to hours.
- Delayed Effect: The steroid medication may take up to 14 days to begin reducing inflammation and providing longer-lasting relief.
- Pain Flare: Some patients experience mild soreness or a temporary flare in pain for 24–48 hours after the procedure.
If the injection is diagnostic, your response will help your provider determine whether the SI joint is the source of your symptoms.
Recovery and Aftercare
- Rest: Take it easy for the rest of the day. Avoid strenuous activities for 24–48 hours.
- Ice: Apply an ice pack to the injection site for 15–20 minutes at a time to relieve soreness.
- Medications: Continue or resume your usual medications unless directed otherwise. Use over-the-counter pain relievers if needed.
- Physical Activity: Most patients can return to light activities within 1–2 days, depending on comfort. Physical therapy may be recommended to strengthen and stabilize the area.
You may be asked to keep a pain diary to track your response and guide future treatment decisions.
How Long Do Results Last?
Relief may last anywhere from weeks to several months, depending on the cause and severity of inflammation.
Risks and Considerations
Sacroiliac joint injections are generally safe, but as with any procedure, there are potential risks:
- Temporary increase in pain
- Bleeding or bruising at the injection site
- Infection (rare)
- Allergic reaction to the medication
- Nerve irritation or leg numbness (very rare)
Your provider will review any specific risks with you before the procedure.