Studies have shown that about 15-30 percent of chronic low back pain can be secondary to the sacroiliac joint. The sacroiliac joint is a large joint located on both the right and left side between the sacrum and iliac bone. The joint can sometimes be injured as a result of minimal trauma (i.e. stepping wrong), more serious trauma, falls or for other unknown reasons, and can produce chronic low back pain, hip pain or leg pain.

Treatment of the sacroiliac joint is usually performed with an injection into the joint along with medications, physical therapy and manipulation therapy. This serves two purposes; first to diagnostically identify the sacroiliac joint as the pain generator, and second to provide pain relief. The procedure is most reliably performed under fluoroscopic guidance to ensure appropriate spread of medication within the joint.