Sacroiliitis is the inflammation of one or both of your sacroiliac joints. These two joints are located where the sacrum (the triangular last section of the spine) meets the ilium (a part of the pelvis).
Sacroiliitis is a common source of lower back pain or pain in the buttocks or thighs. It is often difficult to diagnose since many other conditions cause pain in the same locations.
Doctors don’t know for sure how many people live with sacroiliitis. However, it has been estimated that between 10 percent and 25 percent of people who report low back pain may have sacroiliitis.
Inflammation of the sacroiliac joint causes most of the symptoms of sacroiliitis. Many medical conditions cause inflammation in the sacroiliac joint, including:
Other causes of sacroiliitis include:
Common symptoms of sacroiliitis include pain that:
Your doctor will ask you about your medical history, including any previous inflammatory disorders or conditions. Other diagnostic tests include:
Most people with sacroiliitis benefit from physical therapy. This treatment helps strengthen and stabilize the muscles surrounding your sacroiliac joints. Physical therapy also makes it easier for you to move your sacroiliac joints through full range of motion.
In some cases, doctors prescribe medications like NSAIDs (Advil®) to help manage pain in the early stages of sacroiliitis. In some cases, doctors inject steroids into your sacroiliac joints to help decrease inflammation and pain. Radiofrequency ablation is considered only if pain relief is temporarily achieved after sacroiliac joint injection. This procedure uses radio waves to heat a small area of nerve tissue to stop it from sending pain signals, thereby reducing pain.
Left untreated, sacroiliitis causes a loss of mobility for some people. Untreated pain also can disrupt your sleep and lead to psychological conditions like depression.
Sacroiliitis associated with ankylosing spondylitis can progress over time. Over time, this type of arthritis causes the vertebrae (bones) in your spine to fuse together and stiffen.
There is no way to prevent sacroiliitis. You may be able to prevent or reduce symptoms by avoiding activities that cause the pain like running or stair climbing.
With treatment, most people with sacroiliitis manage their pain and regain mobility.
If you have ongoing pain in the lower back, buttock, or thigh, contact your doctor for a thorough evaluation.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 03/13/2018