Sacroiliac (SI) joint injections are typically only recommended for people with chronic or severe back pain who haven’t had success with more conservative treatments. According to research, these injections are often effective at providing pain relief that can last several months.

Your sacroiliac (SI) joint is located between the flat bone at the base of your spine, called your sacrum, and your pelvis. It’s estimated that the SI joint may cause up to 25% of lower chronic back pain.

An anatomical illustration of the sacroiliac (SI) joint, pelvis, and hip bone. Share on Pinterest
Illustrated by Jason Hoffman

SI joint injections involve having a combination of corticosteroids and pain relievers injected directly into the joint to ease pain and inflammation. If these injections lower your pain, it may also help confirm that your SI joint is the part of your back that’s causing your pain. In other words, there’s a diagnostic value to these injections.

Doctors often recommend injections when more conservative treatments like rest or pain relievers aren’t enough to manage your pain. Although SI joint injections can potentially be effective at relieving discomfort, the effects are temporary.

Read on to learn more about the effectiveness of SI joint injections for managing back pain.

SI joint injections can be effective at providing short-term pain relief that can last for several months. These injections are usually only recommended for people with chronic or severe back pain who haven’t had success with more conservative treatments such as:

Research has found conflicting results about how effective SI joint injections are for treating SI joint pain, but they seem to benefit at least some people.

Some studies report that up to 90% of people experience pain relief when they receive image-guided injections. Image-guided injections use imaging such as computed tomography (CT scan), or a type of X-ray with contrast dye called fluoroscopy, to make sure the injection is going into the right place.

In a small 2022 study, researchers examined the effectiveness of SI joint injections at providing short-term and long-term pain relief. The 27 people in the study were given a steroid called triamcinolone and a pain reliever called ropivacaine. The participants then had follow-up appointments 4 weeks, 8 weeks, and 6 months later.

The researchers found that the study participants had significant reductions in pain, especially at 4 weeks, but they continued to have improvements in pain at 8 weeks and 6 months compared to the baseline.

In a slightly larger study published in 2021, researchers found similar results. A group of 52 people given a mixture of the steroid methylprednisolone and the pain reliever lidocaine experienced significant long-term pain relief when given CT- and fluoroscopy-guided injections.

Learn more about other treatment options for SI joint pain.

SI joint injections involve having medication injected directly into your SI joint. Doctors often use imaging, such as a CT scan or fluoroscopy X-ray, to guide the injections.

Before your procedure

Your doctor may tell you to avoid eating for up to 4 hours before your injection and to avoid applying lotions or creams around your SI joint on the day of your procedure.

During your procedure

Here’s a general idea of what you can expect during your procedure.

  1. You’ll lie face down on your stomach and will likely have a pillow placed under your hips. You may be offered a sedative to help you relax.
  2. The area around your SI joint will be sterilized. If imaging is being used to guide the injection, the machine will be placed over your spine.
  3. Usually, you’ll be given a local anesthesia through a small needle to numb the area around your SI joint.
  4. Your doctor will then inject a combination of a pain reliever and a corticosteroid into the SI joint. The injection usually isn’t painful.
  5. Your doctor may use a small amount of a contrast dye (a solution that makes things more visible on CT scans or X-rays) to confirm that the needle is in the correct position. The contrast dye will be mixed with the steroid and numbing medicine to help the doctor see where the injection is flowing.

After your procedure

After your procedure, you’ll usually be observed for about half an hour to make sure you don’t have any side effects.

You may have some soreness around the injection site the next day. It’s important to contact your doctor if you develop any concerning side effects such as pain, swelling, redness, or leg weakness.

You may start to experience pain relief in as little as 24 to 48 hours after having the injection. In a 2017 study, researchers found evidence that people who don’t have an initial response to SI joint injections are unlikely to achieve significant pain relief later on.

Most people have significant pain relief for at least 6 weeks, and some people have improvements for up to 6 months.

Doctors usually don’t recommend having more than 3 steroid injections in a 1-year period.

If SI joint injections aren’t effective at easing back pain, a sacroiliac joint fusion may be an option. This approach can prevent the bones from grinding against each other and may help reduce pain caused by the SI joint.

SI joint injections are usually safe and have a low risk of serious side effects.

In a 2022 study, researchers found that the most common side effects among 50 people who received SI joint injections were:

Pain at injection site54%
Radiating pain24%
Mild bleeding6%

More serious potential side effects of SI joint injections can include:

  • an allergic reaction to one of the medications, which may cause
    • redness, swelling, or itching around the injection site
    • trouble breathing or swallowing
    • swelling of your hands, face, or mouth
  • worsening pain
  • leg weakness
  • nerve damage
  • infection, which might cause:
    • swelling
    • pain
    • redness

Although these side effects are rare, it’s important to get medical attention right away if you develop any of these symptoms.

SI joint injections involve having a combination of a corticosteroid and a pain reliever injected into your lower back to reduce back pain and inflammation. These injections can be effective at reducing chronic or severe pain when more conservative options aren’t effective.

The effects of SI injections are temporary. However, pain relief can last for several months. If an SI joint injection works but then wears off, you can get another one.

If you have chronic SI joint pain, talk with your doctor about SI joint injections. Your doctor can go over the risks and benefits, and help you understand if these injections are right for you.