Sacroiliac Joint Injections

Written by Staff | 30 October 2011

The sacroiliac (SI) joint connects the spine with the pelvis, and is a significant source for low back, buttock, groin and lower extremity pain. Dysfunction of the joint has been estimated to affect between 15–38% of the general population¹. The most common painful condition of the sacroiliac joint is known as sacroiliac joint dysfunction, which is often caused by direct impact to the buttocks, motor vehicles accidents, or via ballet or ice skating injuries². It can also be caused by arthritis, infection, or simply as the result of age-associated degeneration. With SI joint dysfunction there is a structural change within the joint with the nearby pelvic and/or sacral bones that induces pain in nearby cartilage or ligaments¹.

The sacroiliac joint (SI) is often overlooked as a source of low back pain, especially since there are relatively few techniques to diagnose SI joint pain². The SI joint can receive referred pain from other locations, further complicating diagnosis¹. Thus, diagnosis of SI joint dysfunction tends to occur after excluding other possibilities. The gold standard to definitively confirm a diagnosis of SI joint pain is through provocative injection of the SI joint, in which an injection of fluid into the joint causes distention and reproduces painful symptoms^{1, 2}. If symptoms are reproduced and SI joint pain is confirmed, the diagnostic injection can be followed with a therapeutic injection for pain relief.

The Procedure

Before considering an injection, a doctor will perform a thorough neurological and musculoskeletal examination focusing on the lower back, hips, pelvis and lower extremities¹. There are a variety of special maneuvers available to the physician to identify SI joint pathology, and the physical examination can also rule out other potential sources of pain other than the SI joint.

If a SI joint injection is deemed appropriate, a patient will lie face down on a table while the site of injection is cleaned with an antiseptic agent such as alcohol. The injection site is selected a few centimeters below the bottom of the joint over the buttocks². The skin of the injection site is then anesthetized before a needle is guided through the skin and into the SI joint. Trained physicians use a technology called fluoroscopy, a real-time x-ray, to safely guide the needle through internal tissues without damaging adjacent nerves, blood vessels or other critical structures. Once the needle is properly positioned in the SI joint, an anesthetic/steroid solution is delivered to reduce inflammation and relieve pain.

Although a relatively safe procedure, injections are not without some risk. Steroid injections can be associated with a temporary increase in pain before any relief is experienced¹. Further, local and systemic side effects can occur with steroid injections such as high blood pressure, skin color changes at the site of injection and elevated blood pressure.

References

1. Williams, K.; Park, A. (2007). Injection Studies. Canale and Beaty: Campbell’s Operative Orthopaedics, 11th Ed. MD Consult Web site, Core Collection.
2. Isaac, Z.; Devine, J. (2008). Sacroiliac Joint Dysfunction. Frontera: Essentials of Physical Medicine and Rehabilitation, 2nd Ed. MD Consult Web site, Core Collection.