Sacroiliac Joint Injection

A sacroiliac (SI) joint injection is a targeted, minimally invasive treatment used to relieve pain in the lower back, buttocks, or legs caused by inflammation or dysfunction of the sacroiliac joint. This joint connects the sacrum (the triangular bone at the base of the spine) to the ilium (the upper part of the pelvis) on both sides. Although small and often overlooked, the SI joints play a critical role in stabilizing the spine and transferring weight between the upper body and legs.

When these joints become irritated due to trauma, arthritis, pregnancy, or mechanical stress, they can produce localized or radiating pain that mimics other spinal conditions such as sciatica or herniated discs. A sacroiliac joint injection delivers anti-inflammatory medication directly into the joint to reduce inflammation and provide diagnostic insight.

Conditions Treated with Sacroiliac Joint Injections

SI joint injections are often used to treat pain resulting from:

• Sacroiliac joint dysfunction – Pain due to abnormal motion or inflammation in the SI joint.
• Sacroiliitis – Inflammation of one or both SI joints.
• Pregnancy-related pelvic pain – Hormonal and physical changes during pregnancy can stress the SI joints.
• Ankylosing spondylitis – An inflammatory arthritis that commonly affects the SI joints.
• Postural or gait imbalances – Muscle imbalances or leg length differences can cause SI joint stress.
• Previous spinal surgery – SI joint pain may develop after lumbar fusion or laminectomy.

To explore these causes in more detail, visit our Conditions Treated section.

How the Procedure Works

Sacroiliac joint injections are performed under fluoroscopic or ultrasound guidance to ensure accurate placement of the needle. After the area is numbed with a local anesthetic, a small needle is guided into the joint space. A mixture of corticosteroid and anesthetic is then injected to reduce inflammation and provide pain relief.

The entire procedure typically takes 10–15 minutes and is performed on an outpatient basis. Patients are monitored briefly after the injection and can usually return home the same day.

What to Expect After Treatment

Some patients experience pain relief within a few hours due to the anesthetic, while others may notice gradual improvement over several days as the steroid takes effect. Pain relief may last several weeks to months, depending on the severity and underlying cause.

In some cases, a series of injections may be recommended. If injections are effective but temporary, additional interventions—such as radiofrequency ablation of the SI joint nerves—may be considered.

Benefits of Sacroiliac Joint Injections

• Targeted relief from low back and pelvic pain
• Helps confirm the SI joint as the pain source
• Outpatient procedure with minimal downtime
• May reduce the need for oral medications or surgery
• Compatible with physical therapy for long-term improvement

Find Relief with Ascent Pain

At Ascent Pain, we specialize in precise interventional techniques that deliver real results. If you’re experiencing persistent lower back or pelvic pain, a sacroiliac joint injection can help diagnose and relieve your discomfort, getting you back to the activities you love.

Call Ascent Pain at (504) 249-7576 or request an appointment online to learn if a sacroiliac joint injection is right for you.