The Structure of the Sacrum of a Female

Description

Centered within the posterior pelvis, the female sacrum sits inferior to L5 and superior to the coccyx, wedged between the right and left os coxae at the sacroiliac joints. Along the dorsal surface, the median sacral crest marks the fused spinous processes, flanked by the intermediate and lateral sacral crests that correspond to the articular and transverse element fusion. Paired posterior (dorsal) sacral foramina open lateral to the crests for the dorsal rami of S1 to S4, while the sacral canal continues inferiorly toward the sacral hiatus, just superior to the coccygeal cornua. Orientation is unambiguous. A posterior view matters because so many palpation points and posterior procedures reference these dorsal landmarks rather than the pelvic surface: the PSIS aligns near the S2 level, the sacral hiatus guides caudal epidural access, and the dorsal foramina relate to the course of the sacral nerve roots implicated in radicular pain patterns. Subtle differences in female pelvic morphology, including a broader pelvis and altered sacral curvature, influence obstetric biomechanics and can change the way load transfers across the sacroiliac joints. This is also where insufficiency fractures and traumatic sacral fractures are often localized and classified, with particular attention to foraminal involvement that predicts neurologic deficit. Use this illustration for gross anatomy teaching on the vertebral column and pelvis, radiology correlation when orienting posterior pelvic CT or fluoroscopy landmarks, and clinical education on sacroiliac joint dysfunction, caudal epidural injection technique, and sacral fracture patterns involving the foramina and canal. It also fits well in atlases or patient-facing materials that need a clean posterior skeletal reference with sacrum and coccyx clearly located in context. Anatomical accuracy verified by SciePro's Medical Advisory Board.