Sacroiliac Joint Pain Heidi Prather, DO and Devyani Hunt, MD Any physician who sees spine patients will at one time or another be faced with discerning sacroiliac joint (SIJ) dysfunction and pain from lumbar spine pathology. What makes it even more difficult is that pain coming from the SIJ is not confined to originate from only the joint; it can comprise both intra- and extraarticular structures. The term “posterior pelvic pain” attempts to better encompass the varying etiologies of dysfunction and includes reference to periarticular structures such as the muscle, fascia, and ligaments around the sacroiliac joint. Although the true prevalence of posterior pelvic pain is unknown, researchers estimate that 15–30% of patients with low back pain have SIJ dysfunction. 1,2 Historically, the diagnosis of posterior pelvic pain was based on sugges- tive history and poorly validated physical exam findings. As a result, arriving at the diagnosis and prescribing treatment can be difficult at best. Controversy has surrounded the diagnosis for other reasons as well. First, the amount of SIJ movement is small in the young adult and moves less with aging. Arguments in the past regarding lack of quantity of motion in a joint making it significant have been put aside in favor of quality and symmetry of motion. Second, no specific historical point or clinical examination technique will solidify the diagnosis. Third, imaging is often not helpful. Radiographs, MRI, bone scan, and CT scans do not differentiate symptomatic from asymptomatic patients. Fourth, the bio- mechanics of the sacroiliac joint and its interactions with the surrounding joints including hip, pubic symphysis, and spine are complex. Research- ers continue to produce new information on force and load transmission across the pelvis. Fifth, there is no gold standard for treatment. Often the clinician is left to use his/her experience in making recommendations. Sixth, is the SIJ dysfunction the chicken or the egg? Often patients may have had a history of lumbar discogenic pain, radiculopathy, facet syndrome, hip pathology, or pubic symphysitis that has resolved but because of adaptive changes that have occurred as a result of the primary problem, SIJ pain may develop. Theoretically the inverse of this could Dis Mon 2004;50:670-683 0011-5029/2004 $30.00 + 0 doi:10.1016/j.disamonth.2004.12.004 670 DM, December 2004