FAQs on Sacroiliac Joint Injection


What is the sacroiliac joint?

Also known as the SI joint, the sacroiliac joint is at the bottom of a person’s back below the lumbar spine on both sides. Where the sacrum needs up SI-joint-300x234with the pelvic bone on both the right and left side, those are the sacroiliac joints. These joints contain cartilage just like the hip or the knee joint, and are prone to arthritis as a person ages.
Although the sacroiliac joint does not have a large amount of motion such as a hip joint, it is enough to cause significant pain when degenerative arthritis is present.


How often does the SI joint cause back pain?

Between 12 and 25% of the time, the sacroiliac joint is the cause of a person’s back pain. It may seem like it is coming from the lumbar spine, but the SI joint should be evaluated as a pain generator.

During periods of joint inflammation, sacroiliitis may cause pain around the joint itself and also refer pain down into the buttocks or up into the lower back.

How is sacroiliac joint pain diagnosed?


The diagnosis of the SI joint as the pain generator for an individual’s pain is not always straightforward. During physical examination the pain management doctor will peform several diagnostic maneuvers that stress the SI joint. If they cause pain, the SI joint is deemed to be the source of the problem.

Imaging studies such as an x-ray or a CAT scan may show arthritis in the SI joint, but it may not be arthritis that is not causing the pain. Just because arthritis is present in a joint does not mean the person will have pain as a result.

It may be that the pain doctor needs to perform an SI joint injection to diagnose the source.

How are these injections performed?

SI-joint-injection1Injections into the sacroiliac joint are performed as an outpatient procedure in a procedure room or an outpatient surgery center. The joint is fairly irregular and jagged, so the best way to do it is with x-ray guidance, called fluoroscopy.

The doctor will numb up the skin and the soft tissues down to the area over the joint. Once the joint has been entered, the pain management doctor will inject contrast medicine to make sure positioning is back. At that point, steroid medication along with numbing medicine is injected into the joint. If the injection produces significant pain relief, then the SI joint can be considered the source of an individual’s pain.

After the injection, patients are typically monitored for 30 to 60 minutes to make sure there is no allergic reaction and vital signs are stable.

How well do these injections work?

For the treatment of SI joint pain, surgery should always be looked at as a last resort. SI joint fusion procedures have a very short track record, therefore, nonoperative methods should be tried first.

pain-relief32Physical therapy, chiropractic treatment, nonsteroidal ant-inflammatory medications, Tylenol, and short-term narcotics may be very helpful in conjunction with the injection. Corticosteroid injections into the SI joint work well 75%-85% of the time usually for months at a time (J Rheumatol. 1996 Apr;23(4):659-64). The amount of pain relief achieved may be a few weeks, or it may be quite a few months. When the pain relief wears off, the injection can be repeated.

Another type of injection that has been working well for SI joint pain are lateral branch blocks. The injections numb the nerve endings that supply sensation to the SI joint and may provide excellent relief along with an injection into the joint.

If the lateral branch block works well and then wears off, a radiofrequency ablation may work well for longer term pain relief. A recent study showed over 50% of patients received dramatic relief for 3 to 6 months (AAPM 2012).

What are the risks of a sacroiliac joint injection?

The risks of these procedures are extremely low. There is a very low risk of infection, bleeding, or a short-term increase in blood sugars or weight gain from the cortisone used.

Usually, these are transient. If the patient is on blood thinners, they should be stopped 5 to 7 days prior to the procedure. Ask your pain management doctor for the specific timeframe.

The Bottom Line

A problem in the SI Joint causes up to 25% of low back pain. Effective treatment exists that is nonoperative, with most injections providing substantial pain relief over 80% of the time. In conjunction with other nonoperative pain management treatments, patients are able to avoid surgery, play with the kids and grandkids again, concentrate better, work more effectively and simply live a better life!

If you or a loved one is suffering from low back or sacroiliac joint pain, let the US Pain Network help. The Network provides directory listings for pain management providers nationwide. Visit THIS PAGE and input your zip code or city, state to find those closest to you!