Sacroiliac Joint: Mimics and Pitfalls

Sacroiliac joint pathology presents a complex diagnostic challenge due to the diverse range of conditions, both mechanical and inflammatory, that can affect the joint. Although axial spondyloarthritis-related sacroiliitis is often the most recognized pathology, numerous other conditions closely mimic axial spondyloarthritis in both clinical presentation and imaging features. This review describes key anatomical aspects of the sacroiliac joint, including its distinct morphology, ligamentous support, and histologic characteristics, essential for understanding and differentiating various pathologies. It also examines detailed imaging findings from magnetic resonance imaging, computed tomography, and radiography in relation to each pathologic condition. By providing a framework for distinguishing between common and rare sacroiliac joint disorders and axial spondyloarthritis, this article will enhance diagnostic accuracy and offer insights into the anatomical nuances that impact clinical and imaging assessments.