Syndromes, Injuries and Diseases   Sacroiliac Joint Pain There are many potential causes of back pain. Effective treatment of back pain almost always follows an accurate diagnosis. When an accurate diagnosis is followed by appropriate treatment that is specific for that condition, the outcome is usually very favorable. One of the potential causes of back pain is sacroiliac joint dysfunction. The sacroiliac joint is one of the largest joints in the body. It forms a space between the sacrum, or base of the spine, and the ileum or wing of the pelvis. The sacroiliac joint is crossed by very strong ligaments which hold the joint together. The joint is further stabilized by the front of the pelvis. There, a much smaller joint known as the pubic symphysis is located. In the majority of people, the sacroiliac joint moves only to a small degree. The joint surfaces are very different from the surfaces of the shoulder joint or hip joint, which are very smooth. The sacroiliac joint surfaces are irregular. The surfaces are not unlike the irregular surfaces that we see in corrugated cardboard. One side matches up with another and sliding within the channels occurs. This can happen while we are changing positions in bed, standing from the sitting position or doing most any other activity of daily living. However, when the joint moves in an unusual position, pain can occur. The theory associated with this joint as a generator of pain is that the bone on one side of the joint can slide out of position with respect to the bone on the opposite side of the joint. When this happens, it can be present for just a few moments or it can last a long time. Symptoms usually include the following: • Pain over the side of the back, low in the back, on the same side as the sacroiliac joint problem. • Pain can be referred from this joint down into the buttock or back of the thigh. • People can feel as if there is a rotation of their hip joint and that their leg, on that side, has turned as well. • In some situations, pain can be felt at the front of the pelvis, down near the pubic bone. • The individual with this condition can also complain of pain that is brought about by movement or lifting. In addition to changes in the position of the joint that precipitate pain, an actual inflammation in the joint, similar to an arthritis can cause pain. In these situations, there may be no changes in the position of the joint itself, but the pain is generated because of the inflammation. Symptoms in this situation would more likely be limited to pain in the low back on the side of the sacroiliac joint and possibly referred to the buttock. An injection of medicine into the joint can also be very helpful. Sometimes, an injection can resolve the problem entirely. Injections into the joint are technically difficult, because the joint is very narrow. A specialized x-ray machine is needed to confirm the placement of the tip of the needle in the joint and also that the medication was delivered where it needs to be. In most cases, a combination of physical therapy and this type of injection is effective. In case it is not, another line of treatment could include performing a procedure to eliminate the ability of the nerve endings in that joint to transmit the sensation of pain. As a last resort, for a chronically unstable joint, surgery can be performed to permanently immobilize the joint in the proper position. This can be very effective as well. But again, it is reserved only as a last resort.