Sacroiliac (SI) Joint Injections

What Is a Sacroiliac Joint Injection?

A sacroiliac joint injection involves delivering a local anesthetic, with or without corticosteroid medication, directly into the SI joint.

This procedure serves two purposes:

1. Diagnostic – To confirm the SI joint as the source of pain.
2. Therapeutic – To reduce inflammation and relieve chronic SI joint pain.

Because SI joint pain can mimic lumbar disc or facet pain, diagnostic injections are critical for accurate identification.

Diagnostic Sacroiliac Joint Injection bn

A diagnostic SI joint injection uses local anesthetic to temporarily numb the joint.

If the patient experiences 75–80% or greater pain relief, sacroiliac joint dysfunction is strongly suspected. A second confirmatory injection is often performed to validate the diagnosis before proceeding with long-term treatment.

Diagnostic criteria typically include:

1. Low back pain lasting at least 3 months
2. Uncertain diagnosis after physical exam and imaging
3. Failure of 4–6 weeks of conservative treatment

Therapeutic Sacroiliac Joint Injection

A therapeutic SI joint injection includes a corticosteroid to reduce joint inflammation.

This injection helps:

1. Decrease pain
2. Improve mobility
3. Reduce inflammation
4. Enable participation in physical therapy

Therapeutic injections may be repeated up to three times per year, depending on clinical response.

Indications for therapeutic injection include:

1. Chronic low back pain lasting at least 3 months
2. Failure of conservative therapy for 4–6 weeks
3. Positive response to a prior diagnostic SI joint injection

Symptoms of SI Joint Dysfunction

Patients with SI joint dysfunction may experience:

1. Low back pain below the belt line
2. Buttock pain
3. Pain radiating into the hip or groin
4. Pain worsened by standing or walking
5. Pain when transitioning from sitting to standing

SI joint pain is often unilateral but may affect both sides.

How the Procedure Is Performed

Sacroiliac joint injections are performed in an outpatient setting under fluoroscopic (live X-ray) guidance.

The procedure includes:

1. Cleaning and sterilizing the lower back area
2. Numbing the skin with local anesthetic
3. Advancing a needle into the SI joint under imaging guidance
4. Injecting contrast dye to confirm accurate placement
5. Delivering anesthetic and corticosteroid medication

The procedure typically takes 15 to 30 minutes.

Benefits of Sacroiliac Joint Injections

• Accurate diagnosis of SI joint dysfunction
• Rapid reduction of inflammation
• Minimally invasive outpatient procedure
• Improved function and mobility
• Reduced reliance on oral pain medications