Posterior Perspective of the Sacrum Bone

Description

Centered in a posterior view of the bony pelvis, the sacrum forms a triangular wedge between the right and left os coxae, with the coccyx continuing inferiorly at the sacral apex. Along the midline, the fused spinous processes create the median sacral crest, flanked posterolaterally by the intermediate and lateral sacral crests that converge toward the sacroiliac region. Paired dorsal sacral foramina perforate the posterior surface lateral to the crest, aligned for the posterior rami of the sacral spinal nerves, while the superior aspect meets L5 at the lumbosacral junction. Posterior sacral anatomy matters when you need reliable landmarks for diagnosis and intervention around the lumbosacral spine and sacroiliac joints. The dorsal sacral foramina and adjacent crests orient procedures such as sacroiliac joint injections and posterior approaches to sacral fracture fixation, where hardware placement must respect the course of the sacral nerve roots. Palpation and imaging correlation also hinge on these contours. Small errors here can mean neural injury. Use this illustration for gross anatomy teaching of the axial skeleton and pelvis, for orthopedic and neurosurgical texts covering posterior pelvic ring trauma, and for pain medicine materials that explain fluoroscopic targeting around the sacral foramina and sacroiliac joint. It also supports radiology education when correlating posterior bony landmarks with CT reconstructions of the sacrum and coccyx. Anatomical accuracy verified by SciePro's Medical Advisory Board.