Sacroiliac Joint Pain is a Pain in the Buttocks

by Christina Lasich, MD Health Professional

Ever had a pain in the butt? No, I am not talking some crazy family member who cannot keep the mouth shut. I am talking about a real pain in the buttock region, possibly confused with low back pain.

A common cause of pain in the area of the tailbone, especially the tailbones in women, is the sacroiliac joint (SIJ). Before we proceed further, let us form a mental picture of [the pelvis]. The pelvis is a boney ring formed by four bones: two fused sections comprised of the pubis, ischium and ilium, one sacrum, and one coccyx. These four sections of bone are joined by strong ligaments at the pubic symphysis (in front) and the sacroiliac joints (in the back). All three of these joining points for the pelvic ring are potential sources of pain, especially in women and most especially in pregnant women. Thus, women in particular need to understand the risks for having SIJ dysfunction, the ways to diagnosis the problem, and the solutions for this pain in the butt.

By virtue of being a woman, the sacroiliac joint is vulnerable to high amounts of stress. Comparing the pelvis of a man versus the pelvis of a woman, one will find major differences in the shape and contour. These differences are necessary for women to be able to push a nine pounder through the birth canal. These differences also increase the amount of stress on the SIJ in women, especially pregnant women. During pregnancy, the stability of the pelvic ring changes as the ligamentous restraints soften. With less ability to resist shear forces, all the joints in the pelvis (pubic symphysis and the SIJ's) can become quite painful. That's right; pregnancy can be a pain in the butt.

Of course, many women experience low back pain as well as SIJ pain. And sometimes it is difficult to decipher between a lumbar source of pain and a sacroiliac source of pain. Over the years, clinicians have argued over which physical exam findings most accurately predict an SIJ problem. Personally, I like to use a series of tests: the active straight leg raise test, the [Patrick's Test], and other provocative shear forces across the SIJ. The greater number of positive tests, the more likely a person has a sacroiliac joint dysfunction.

However, most physical exam findings are still considered unreliable. The "gold standard" reliable method for diagnosing SIJ pain is to perform nerve blocks. Because the SIJ is considered the last facet joint of the spine, this joint lends itself to diagnostic nerve blocks. By blocking the nerve signals that come from the SIJ, pain that is truly coming from that pelvic joint can be interrupted temporarily. If the pain is successfully interrupted, then the SIJ is indentified as the culprit and the diagnosis is confirmed. Once the diagnosis is confirmed, the treatment for this pain in the butt is more likely to be successful.

Some very specific treatments exist for the SIJ; thus, traditional treatments for low back pain are usually not specific enough to be successful if the source of pain is actually coming from the SIJ. That is why it is important to distinguish between the two sources of pain: lumbar and sacroiliac joint. For example, a traditional back brace does not reach low enough to support the SIJ. Those with SIJ pain should try a specific support called a sacroiliac belt that wraps around the pelvis. Additionally, traditional lumbar stabilization exercises may not significantly incorporate the pelvic floor muscles. Those with SIJ pain need a more specific pelvic floor rehabilitation program such as those found at the Cleveland Clinic, [UCLA], and UCSF. Finally, lumbar fusion does not relieve pain that is actually coming from the SIJ. A specific fusion procedure is needed to stabilize the sacroiliac joint. But again, without the correctly identifying a problem with the SIJ, all of these specific treatments may be overlooked and the pain in the butt can go unresolved.

No one wants to live with a pain in the butt. Solving sacroiliac joint pain requires identifying those who are at risk, confirming the diagnosis, and specifically directing treatment. Oftentimes, both the lumbar spine and the pelvis will be simultaneous sources of pain. In order to successfully treat those cases, the SIJ still requires special attention. For that matter, women in pain require special attention because we are built differently than men. And we are more likely to have sacroiliac joint pain.

Christina Lasich, MD
Meet Our Writer
Christina Lasich, MD

Christina Lasich, M.D., wrote about chronic pain and osteoarthritis for HealthCentral. She is physiatrist in Grass Valley, California. She specializes in pain management and spine rehabilitation.