Medial Part Of The Sacrum, Posterior View

Description

Sacrum midline anatomy dominates this posterior view, centered on the median sacral crest formed by fused sacral spinous processes from S1 to S4. Immediately lateral to the crest, the paired intermediate sacral crests correspond to the articular processes, while the posterior sacral foramina sit farther lateral and step inferiorly with each sacral segment. Inferiorly, the sacral canal opens at the sacral hiatus, bordered by the sacral cornua and tapering toward the coccygeal articulation. Surface ridges and foraminal margins are presented from a fixed posterior perspective that keeps the medial landmarks in strict alignment along the midsagittal plane. Posterior sacral midline landmarks matter in pain medicine and regional anesthesia, where accurate identification of the sacral hiatus guides caudal epidural access and helps avoid subperiosteal injection. Variants such as a narrow hiatus, absent cornua, or partial nonfusion of the laminae (often discussed with spina bifida occulta) change palpation and needle trajectory, and the relationships in this illustration translate directly to that bedside anatomy. Orthopedic and trauma contexts also benefit, since insufficiency fractures and posterior element injuries are often described relative to the crests, foramina, and canal. Small structures, big consequences. Faculty can place this illustration in pelvic girdle and vertebral column modules to anchor terminology for the dorsal sacral surface and to contrast medial versus lateral sacral morphology. It also fits surgical consent materials and pain clinic education sheets that explain caudal epidural approach using the sacral hiatus, cornua, and canal as named landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.