SI Joint Anatomy, Biomechanics & Prevalence

To speak with a nurse or find a surgeon call 888-689-5277 or visit Learn more about the sacroiliac joint at . The SI Joint is the connection between the spine and the pelvis. The SI Joint is a true diarthrodial joint. The articular surfaces are ear shaped, containing irregular ridges and depressions. Its concave sacral surface is covered with thick hyaline cartilage and its convex iliac surface lined with thin fibrocartilage.