Dorsal Surface Of The Sacrum

Description

Sacrum anatomy on the dorsal (posterior) surface centers on the median sacral crest, a midline ridge formed by fused spinous processes that runs inferiorly toward the sacral hiatus. Lateral to it, the intermediate sacral crests mark the fused articular processes, and the lateral sacral crests sit farther laterally as irregular elevations related to fused transverse processes. Four pairs of dorsal sacral foramina punctuate the surface on each side, positioned lateral to the intermediate crest and transmitting the dorsal rami of the sacral spinal nerves, while the inferior apex region shows the sacral cornua flanking the sacral hiatus. Posterior sacral topography matters in procedures that rely on palpable bony landmarks, where a few millimeters determine needle trajectory or incision placement. The relationship between the sacral cornua, sacral hiatus, and the inferior termination of the sacral canal underpins caudal epidural access, and the dorsal foramina provide a map for targeting dorsal sacral nerve branches in posterior pelvic pain interventions. Surface irregularity is not decorative. It explains why posterior sacral fractures can be hard to assess clinically and why implant placement near the sacroiliac region must respect the foraminal corridors and the midline crest. Anatomy educators often pair this illustration with lumbosacral spine and pelvis modules to teach vertebral fusion patterns, foraminal organization, and orientation of posterior bony landmarks in the prone patient position. Surgical atlases and pain medicine texts can also use it to support discussions of caudal epidural technique, sacral insufficiency fractures, and posterior approaches that navigate between the crests and around the dorsal sacral foramina. Anatomical accuracy verified by SciePro's Medical Advisory Board.