Radiculopathy with concomitant sacroiliac dysfunction and lumbosacral degenerative disease: illustrative case

BACKGROUND The sacroiliac joint (SIJ) is an important cause of low back pain and referred leg pain (RLP). Pain from SIJ dysfunction may occur in isolation or may result from a combination with lumbosacral area–mediated pain. SIJ fusion is one treatment modality for medically refractory symptoms and may also have a role in the treatment of RLP. OBSERVATIONS The authors present a challenging case of concomitant lumbosacral degenerative disease and SIJ dysfunction in a patient with radiculopathy. They provide clinical characteristics and imaging findings and discuss difficulties in dealing with the intersection of these two distinct diagnoses. In addition, the authors offer a review of the relevant literature, elucidating the role of SIJ dysfunction in causing radicular lower extremity pain, the relationship to concomitant lumbosacral degenerative disease, and outcome data for SIJ fusion as it relates to RLP. LESSONS With increasing numbers of patients undergoing spinal instrumentation in the setting of degenerative lumbosacral arthritis, as well as randomized controlled trial data demonstrating the efficacy of SIJ fusion for medically refractory SIJ dysfunction, it is important to recognize the challenges in understanding how both of these patient groups may present with radiculopathy. Failure to do so may result in incorrect patient selection, poor outcomes, and increased morbidity for at-risk patients.