Anatomical Location Of Arcuate Line Of The Ilium On The Hip Bone

Description

Arcuate line of the ilium forms a smooth ridge along the internal (medial) surface of the iliac ala, curving inferoanteriorly from the region of the auricular surface toward the superior pubic ramus. From this fixed medial perspective, the ridge lies inferior to the iliac fossa and superior to the pelvic surface of the ilium, creating a visible boundary between the false (greater) pelvis above and the true (lesser) pelvis below. Anteriorly it approaches the iliopubic eminence and continues conceptually onto the pecten pubis as part of the linea terminalis. It is a bony landmark. Clinically, the arcuate line is one of the key components of the pelvic brim, used to define the pelvic inlet and to orient obstetric measurements when assessing cephalopelvic disproportion and pelvic type. Pelvic and acetabular trauma discussions also reference this ridge when describing internal pelvic ring anatomy and fracture propagation across the ilium, where disruption can change the contour of the inlet. The isolated bony surface and crisp edge definition in this illustration make it easy to teach the ridge as a landmark rather than confusing it with nearby muscle attachment areas on the iliac fossa. Use this illustration in gross anatomy and osteology lab manuals, obstetrics and gynecology teaching decks covering pelvic inlet boundaries, and orthopedic or trauma publications that need a labeled medial hip bone landmark for the pelvic brim. Anatomical accuracy verified by SciePro's Medical Advisory Board.