What is a sacroiliac joint injection?

A sacroiliac joint injection is used to diagnose or treat low back pain that comes from your sacroiliac joint. This joint is the place where your spine connects to your pelvis. For the procedure, your healthcare provider injects medicine directly into the joint to ease pain.

Why might I need a sacroiliac joint injection?

Your healthcare provider might do a sacroiliac joint injection to diagnose or treat pain that may be coming from your sacroiliac joint. This joint connects the bone at the base of your spine (sacrum) to the large pelvis bones (ilium). You have 2 sacroiliac joints, 1 on each side of the body. They connect the sacrum to each side of the pelvis. These joints act as shock absorbers. They transmit weight and forces between the upper body and the legs.

Some pain in the low back, buttock, or hip may come from these sacroiliac joints. A sacroiliac joint injection is a good way to find out if your pain is from a problem in the sacroiliac joint. The procedure can also help to treat pain from that area.

For this procedure, your healthcare provider injects numbing medicine (local anesthetic) into the joint. They may use X-rays (fluoroscopy) to show where to place the needle. They may also use a small amount of X-ray contrast dye. It can help make sure the needle is in the right place so that the medicine goes directly into the joint.

A sacroiliac joint injection may be used to diagnose or treat a problem. During a diagnostic injection, the healthcare provider injects only numbing medicine into the joint. If your pain eases, then your sacroiliac joint is likely the cause of your pain. An injection used for treatment is called a therapeutic injection. This type of injection uses numbing medicine and steroid medicine to treat pain that comes from the sacroiliac joint. It decreases inflammation in the joint.

What are the risks of a sacroiliac joint injection?

Sacroiliac joint injections are generally safe. Some possible risks of the procedure are:

• Infection at the injection site

• Bleeding at the injection site

• Nerve damage

• Leg weakness

• Increased pain

• Allergic reaction to the medicines

If you get steroid medicine in your shot, you may have some side effects. These include short-term (temporary) increases in blood sugar levels for 1 to 2 days, an allergic reaction, and flushing of your face.

You may have other risks based on your specific situation and other health problems. Discuss any concerns with your healthcare provider beforehand.

How do I get ready for a sacroiliac joint injection?

You will talk with your healthcare provider about your past health. Let them know if you have an infection, fever, or any other recent health problems. If you have diabetes or use any blood-thinning medicines, check if you need to take any special safety measures.

You should also discuss all your medicines with your healthcare provider. You may need to stop taking certain medicines a few days before the shot. Also be sure to tell your healthcare provider if you:

• Have any allergies

• Have had any problems with contrast dyes, past injection procedures, or other medicines

• Are breastfeeding, pregnant, or may be pregnant

Your healthcare provider may tell you not to eat or drink after midnight the night before the procedure. You may get medicine to help you relax during the injection. You should arrange to have someone drive you home afterward. Your provider may give you other instructions about how to get ready.

What happens during a sacroiliac joint injection?

Your exact procedure may differ. But these are the general steps for a sacroiliac joint injection:

• You will lie face down on an X-ray table.

• You may get medicine to help you relax (sedation).

• The skin on your lower back and buttocks will be cleaned.

• The healthcare provider will use medicine to numb the skin around the injection area. It may burn and sting a little. But it should last only a few seconds.

• The provider puts the needle tip into the sacroiliac joint. They will use X-rays to guide the needle. You may have pain in this area as the needle enters the joint.

• The provider injects a small amount of the X-ray contrast dye through the needle. It will confirm that the needle tip is in the joint.

• The provider injects the medicine into the joint. This medicine may include a local anesthetic to block the pain. It may also include a steroid to reduce inflammation. You may also feel a stinging or burning during the shot. This feeling often lasts just a few seconds.

• The needle will be removed, and a bandage will be applied.

What happens after a sacroiliac joint injection?

You will be watched for about 30 to 60 minutes after the procedure. Then someone can drive you home. Ask your healthcare provider about any activity restrictions after the procedure. You should also ask if it is OK to use heat or ice in the area of the shot and if it is safe to bathe that day. Make sure to follow all your provider’s instructions for care, including any directions about your medicines.

You may be sore from the injection. You may also have some slight weakness in your leg for a few hours after the shot. If your pain comes from the sacroiliac joint, you may feel pain relief in the hours after the procedure because of the numbing medicine. As it wears off, the pain may start to feel worse.

If your healthcare provider gives you a steroid medicine, it may take up to 7 days for the medicine to start reducing pain and inflammation in the joint. As a result, you may feel better for the first few hours after the shot. But the pain may get worse for a few days before the steroid starts working.

Your provider might ask you to keep a diary of your pain after the injection. A diary can help find out if your pain comes from the sacroiliac joint. It can also be used to decide how helpful an injection may be in the future.

Call your provider if you have any of these symptoms:

• Severe pain

• Weakness or numbness in the leg that lasts more than a few hours

• Fever

• Bleeding at the injection site

• Signs of infection at the injection site. These include redness, swelling, and oozing.

Your healthcare provider can tell you more about what you should do and what you can expect after the sacroiliac joint injection. You will need to follow up with your provider to talk about the effects of the procedure and make a plan for future treatment of your pain.

Next steps

Before you agree to the test or the procedure, make sure you know:

• The name of the test or procedure

• The reason you are having the test or procedure

• What results to expect and what they mean

• The risks and benefits of the test or procedure

• What the possible side effects or complications are

• When and where you are to have the test or procedure

• Who will do the test or procedure and what that person’s qualifications are

• What would happen if you did not have the test or procedure

• Any alternative tests or procedures to think about

• When and how you will get the results

• Who to call after the test or procedure if you have questions or problems

• How much you will have to pay for the test or procedure