When to Consider Sacroiliac Joint Injections

Lower back pain is one of the most common reasons people seek medical care, but not all back pain originates from the spine itself. In some cases, the discomfort comes from the sacroiliac (SI) joints—two small but important joints located where the lower spine meets the pelvis. When these joints become inflamed or dysfunctional, they can cause significant pain and mobility limitations. Sacroiliac joint injections are one treatment option that can both diagnose and relieve SI joint–related pain.

Understanding when these injections may be appropriate can help patients make informed decisions about their pain management plan.

Understanding the Sacroiliac Joint

The sacroiliac joints sit on either side of the sacrum, which is the triangular bone at the base of the spine. These joints connect the spine to the pelvis and play a key role in transferring weight and forces between the upper body and the legs.

While the SI joints do not move as freely as other joints in the body, they provide stability and help absorb shock during activities like walking, standing, or bending. When the joints become irritated or inflamed, the resulting condition—often called sacroiliac joint dysfunction—can lead to chronic pain.

SI joint pain often presents as discomfort in the lower back, buttocks, or hips, and it may radiate down the legs. Because these symptoms overlap with other spinal conditions, diagnosing SI joint pain can sometimes be challenging.

Common Causes of SI Joint Pain

• Degenerative arthritis: Wear and tear over time can affect the SI joints just as it does other joints in the body.
• Injury or trauma: Falls, car accidents, or sudden twisting motions can damage the ligaments supporting the SI joint.
• Pregnancy: Hormonal changes and increased pelvic stress during pregnancy can loosen the ligaments around the SI joints.
• Previous spine surgery: Changes in spinal mechanics following procedures such as lumbar fusion may place additional stress on the SI joints.
• Inflammatory conditions: Disorders such as ankylosing spondylitis can lead to inflammation in the SI joints.

Signs You May Need an SI Joint Injection

Not every case of SI joint pain requires an injection. However, physicians may recommend sacroiliac joint injections in certain situations.

One common reason is persistent pain that has not improved with conservative treatments. These may include rest, physical therapy, anti-inflammatory medications, or activity modifications. If these approaches fail to provide sufficient relief, injections may be considered.

Another reason is diagnostic clarification. Because SI joint pain can mimic other spinal conditions such as herniated discs or lumbar facet joint pain, an injection can help confirm whether the SI joint is truly the source of the problem.

Patients who often benefit from SI joint injections typically experience pain that worsens with prolonged sitting, standing, climbing stairs, or transitioning from sitting to standing.

How Sacroiliac Joint Injections Work

A sacroiliac joint injection involves delivering medication directly into the affected joint. The procedure is typically performed using imaging guidance—such as fluoroscopy (live X-ray)—to ensure precise placement of the needle.

The injection usually contains two components:

• A local anesthetic, which provides immediate but temporary pain relief.
• A corticosteroid medication, which reduces inflammation within the joint and may provide longer-lasting relief.

If the anesthetic portion of the injection significantly reduces pain shortly after the procedure, it helps confirm that the SI joint is the primary pain source.

What to Expect During the Procedure

Sacroiliac joint injections are typically performed in an outpatient setting and usually take less than 30 minutes.

After the patient lies comfortably on an exam table, the physician cleans the skin and administers a local anesthetic to numb the area. Using imaging guidance, the physician carefully guides a thin needle into the SI joint and injects the medication.

Most patients experience minimal discomfort during the procedure. Some may feel temporary pressure or mild soreness at the injection site afterward.

Patients are generally able to return home the same day, though physicians may recommend avoiding strenuous activities for the rest of the day.

Benefits of SI Joint Injections

• Reduced inflammation and pain relief
• Improved mobility and daily function
• Diagnostic confirmation of SI joint pain
• Greater ability to participate in physical therapy

When to Talk to Your Doctor

Persistent lower back or pelvic pain should never be ignored, particularly if it interferes with daily activities or quality of life. If conservative treatments have not provided adequate relief, discussing additional options with a pain management specialist may be helpful.

Sacroiliac joint injections are not the right solution for everyone, but for patients with confirmed SI joint dysfunction, they can be an effective part of a comprehensive treatment plan.

Moving Toward Long-Term Relief

While injections can provide meaningful relief, they are often just one component of a broader pain management strategy. Physical therapy, strengthening exercises, lifestyle adjustments, and other interventional treatments may also play important roles in long-term recovery.

By identifying the root cause of pain and tailoring treatment to the individual patient, physicians can help people regain mobility, improve function, and return to the activities they enjoy.