Sacroiliac Joint Pain

Often difficult to diagnose, sacroiliac joint dysfunction is commonly thought of as a source of lower back pain and/or leg pain. The sacroiliac joint, or SI Joint, is the connecting joint for the pelvic bone and the sacrum. Dysfunction in the sacroiliac joint is thought to cause low back and/or leg pain. The leg pain can be particularly difficult, and may feel similar to sciatica or pain caused by a lumbar disc herniation.

While it is not clear how the pain is caused, it is thought that an alteration in the normal joint motion may be the culprit that causes sacroiliac pain. This source of pain can be caused by either:
  • Too much movement (hypermobility or instability): The pain is typically felt in the lower back and/or hip and may radiate into groin area.
  • Too little movement (hypomobility or fixation): The pain is typically felt on one side of the low back or buttocks, and can radiate down the leg. The pain usually remains above the knee, but at times pain can extend to the ankle or foot. The pain is similar to sciatica, or pain that radiates down the sciatic nerve and is caused by a radiculopathy. It is important to discuss your symptoms with your physician at Restore medical partners as sacroiliac joint inflammation may mimic lumbar radiculopathy. We will complete a thorough history and physical and interventional procedure testing to ensure an accurate diagnosis.

This condition is generally more common in young and middle-aged women.


The term sacroiliitis is used to describe any inflammation in the sacroiliac joint, which is located on either side of the sacrum (lower spine) that connects to the iliac bone in the hip. Sacroiliitis is often found alongside inflammatory conditions of the spinal column. As a group, these conditions and diseases are termed a "spondyloarthropathy" and include conditions such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis, among others. Sacroiliitis may also be a component of other types of arthritis, such as ulcerative colitis, Crohn’s disease, or osteoarthritis.

To watch a video about SI joint dysfunction, please click here:

Sacroiliitis vs. Sacroiliac Joint Dysfunction
Both sacroiliitis and sacroiliac joint dysfunction are a common cause of sacroiliac pain, low back pain, and leg pain. However, there are differences between the two conditions:
  • Sacroiliitis: In medicine, the term "itis" refers to inflammation, and sacroiliitis describes inflammation of the sacroiliac joint. The inflammation may or may not be caused by sacroiliac joint dysfunction.
  • Sacroiliac Joint Dysfunction: This condition generally refers to pain in the sacroiliac joint region that is caused by abnormal motion in the sacroiliac joint, either too much motion or too little motion. It typically results in inflammation of the SI joint, or sacroiliitis.
    Sacroiliitis Symptoms

    The most common symptoms of sacroiliitis include some combination of the following:

    • Fever
    • Pain, usually low back pain, leg pain (may be in the front of the thigh), hip pain, and/or buttock pain
    • Pain that is worse when sitting for a long time, and worse when rolling over in bed
    • Stiffness felt in the hips and low back, especially after getting out of bed in the morning or after sitting still for a prolonged period.
    Sacroiliitis Causes
    • A wide range of factors may cause sacroiliitis or predispose one to developing sacroiliitis:
    • Any form of spondyloarthropathy, which includes ankylosing spondylitis, arthritis associated with psoriasis, and other rheumatologic diseases, such as lupus
    • Degenerative arthritis, or osteoarthritis of the spine, causing degeneration of the sacroiliac joints and in turn leading to inflammation and SI joint pain
    • A trauma that affects the lower back, hip or buttocks, such as a car accident or fall
    • Pregnancy and childbirth, as a result of the pelvis widening and stretching the sacroiliac joints during childbirth
    • Infection of the sacroiliac joint
    • Osteomyelitis
    • Urinary tract infection
    • Endocarditis
    • IV drug use/drug addition

    If a patient has pain in the sacroiliac area and any of the above conditions, he or she may have sacroiliitis or sacroiliac joint dysfunction.

    At Restore Medical Partners, we will ask patients to describe the location, severity and type of pain, in addition to the history of the pain: when the patient started to feel it, and any activities or positions that make the pain better or worse. We will review your MRI or order imaging if you do not have imaging completed on your first visit. Then, we will explain to you what is causing your low back/buttock pain. Our goal is to prevent major surgery and use minor interventional techniques to relieve your pain and get you back to doing the things you enjoy. For SI joint pain, we may recommend a series of therapeutic SI joint injections. If you respond really well to these injections, but only for a short period of time we may consider radio frequency ablation. This involves using a small needle to burn the small nerves that carry pain fibers to your si joint, Some patients may require a combination of techniques to completely resolve your pain symptoms.