Sacroiliac Joint Pain

Abstract Sacroiliac joint pain represents a frequently misdiagnosed cause of low back pain, affecting between 15% and 30% of individuals with mechanical pain below L5. Although a battery of provocation maneuvers can identify most cases of sacroiliac joint pain with reasonable specificity, the reference standard is low-volume blocks, which are associated with a false-positive rate ranging between 10% and 30%. Between 40% and 50% of cases are caused by a specific inciting event, which can include motor vehicle collisions, falls, or more insidious etiologies, such as pregnancy, spinal fusion, and leg length discrepancies. Sacroiliac joint pain may be secondary to both intraarticular and extraarticular pathology, with the latter more likely to be unilateral and affect younger individuals. Both intraarticular and extraarticular steroid blocks have been shown to provide short- to intermediate-term and are sometimes used to select patients for radiofrequency denervation or fusion. Since the lateral branches targeted during denervation innervate the ligaments, those with extraarticular pathology are more likely to benefit. Minimally invasive fusion should be reserved for individuals with dislocation or degeneration with instability who have failed more conservative therapies.