Body Of The Ilium, Posterior View

Description

Ilium body anatomy dominates this posterior perspective of the os coxae, with the thickened region inferior to the iliac wing and superior to the ischium forming the posterior rim and superior wall of the acetabulum. Posteriorly, the posterior superior iliac spine and posterior inferior iliac spine bracket the posterior border, while the greater sciatic notch curves inferiorly toward the ischial spine outside the field of the acetabular cavity. Medially, the auricular surface for the sacrum and the adjacent iliac tuberosity occupy the posteromedial aspect, positioned deep to where the iliac crest would sweep superiorly out of the frame. Surface relief on the gluteal (external) aspect transitions from the wing into the body, with the posterior gluteal line approaching the posterior border. Sacroiliac joint anatomy is the main clinical payoff: the auricular surface and iliac tuberosity mark the load-transmitting region implicated in degenerative sacroiliitis, inflammatory spondyloarthropathy, and postpartum pelvic girdle pain. Palpation landmarks align here as well, since the PSIS corresponds closely to the “dimples of Venus” and guides bedside localization for sacroiliac provocation tests and fluoroscopy or ultrasound planning for SI joint injections. Bony thickness in the iliac body also matters in trauma, where fractures extending from the greater sciatic notch toward the acetabulum can destabilize the posterior column and complicate fixation planning. Orthopaedic and radiology teaching files can pair this illustration with acetabular fracture patterns and posterior pelvic ring disruptions. It also fits gross anatomy labs, physiotherapy modules on pelvic girdle mechanics, and procedural guides addressing SI joint access and posterior pelvic landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.