What is an SI injection?
A sacroiliac injection places a pain-numbing medicine and steroid directly into the sacroiliac (SI) joint. There are two sacroiliac joints, one located on either side of the sacrum (see arrow pointing to the left sacroiliac joint). The benefit of this procedure is to reduce inflammation, help confirm the SI joint as the source of pain, and better allow a physical therapist to treat the joint.
Click the image to enlarge.
How is the procedure done?
You will receive a local anesthetic before a small spinal needle is inserted under fluoroscopic guidance into the SI joint. The procedure takes approximately 15 minutes. The arrow shows the needle within the sacroiliac joint.
What should I do the day of the procedure?
- You may eat a light meal a few hours before the procedure.
- If you are an insulin-dependent diabetic, it’s important not to change your normal eating pattern prior to the procedure.
Does the procedure hurt?
Because the procedure is done under local anesthesia, you should not experience much discomfort.
What should I expect after the procedure?
The local anesthetic may completely eliminate your pain for a few hours. However, the pain may return and you may have sore buttocks for a day or two. Within three to five days, you should start noticing significant pain relief, which may last up to many months.
If you have some soreness, you may apply ice packs hourly for 15-20 minutes at a time for the first 48 hours.
How soon can I return to work?
Twelve hours after the procedure, you can perform normal activities as long as they are not uncomfortable. Barring complications, you should be able to return to work the day after the procedure.
How many injections should I have?
We generally do not perform more than three injections within a one-year period. Giving more injections can increase the likelihood of side effects from the steroid. In addition, if three injections within a year have not helped you much, it is very unlikely that you will get any further benefit from additional injections.
Can I have this procedure if I am on Coumadin®?
No. You should not have the procedure if you are currently taking blood-thinning medication. Ask your doctor, however, before stopping any medications.
Are there any risks with this procedure?
Some temporary discomfort is normal. However, other risks involved with the injection include infection, bleeding, and worsening of symptoms. Although rare, there are side effects that are related to steroid, including:
- Fluid retention
- Weight gain
- Increased blood sugar (primarily in diabetics)
- Elevated blood pressure
- Mood swings