Auricular Surface Of The Sacrum, Lateral View

Description

Sacral auricular surface occupies the lateral aspect of the upper sacrum, forming an ear-shaped articular area on the ala adjacent to the body of S1. From a lateral perspective, the concave pelvic surface of the sacrum lies anteriorly while the roughened dorsal surface sits posteriorly, and the auricular surface bridges between them as it faces laterally toward the ilium. Superiorly, the base of the sacrum and the region of the sacral promontory are implied; inferiorly the auricular area tapers toward the level of S3, blending into nonarticular tuberosity for ligament attachment. Bone texture matters here. Sacroiliac joint anatomy is a frequent pain generator and a common target for injection, fusion, and trauma assessment, so a focused view of the auricular surface helps clarify where the true synovial articulation sits versus the adjacent sacral tuberosity that anchors the interosseous and posterior sacroiliac ligaments. Irregular ridging and subtle curvature on this surface correlate with age-related remodeling and degenerative sacroiliitis patterns, and they also explain why screw trajectories and implant footprints must respect the joint line rather than the rough ligamentous zone. Lighting and surface relief in the illustration support teaching the distinction between articular cartilage-bearing bone and the more porous, nonarticular attachment area. Orthopedic and pain-medicine texts can pair this illustration with sacroiliac joint blocks, posterior pelvic ring fixation, and discussions of pelvic instability after high-energy trauma. It also fits well in gross anatomy and osteology modules when students learn sidedness of the sacrum and how the axial skeleton locks into the pelvic girdle at the sacroiliac joint. Anatomical accuracy verified by SciePro's Medical Advisory Board.