Sacrum, Posterior View

Description

Centered at the inferior end of the vertebral column, the male sacrum is highlighted in contrast to the lumbar vertebrae superiorly and the coccyx inferiorly, all presented from a posterior perspective. The dorsal surface shows the median sacral crest in the midline, flanked bilaterally by the intermediate sacral crests and the paired posterior (dorsal) sacral foramina arranged in longitudinal rows. Laterally, the sacral ala and the auricular regions for the sacroiliac joints broaden toward the ilium, while the sacral hiatus and cornua sit at the inferior apex where the laminae of S5 fail to fuse. Posterior sacral landmarks matter because they guide both diagnosis and procedures around the sacral canal and sacroiliac complex. Palpation of the median sacral crest and the sacral hiatus helps orient caudal epidural anesthesia and steroid injections, where a too-superior trajectory risks dural puncture and a too-lateral path may miss the canal. Pain patterns attributed to sacroiliac joint dysfunction also benefit from clear appreciation of the auricular surface location relative to the dorsal foramina and the posterior superior iliac spine region. A difficult area to visualize mentally. Use this illustration in gross anatomy and osteology teaching to anchor orientation of the posterior pelvis and lower spine, and in anesthesia, pain medicine, and physical therapy materials explaining caudal epidural approach and sacral landmark palpation. It also suits atlas pages and patient-facing diagrams where the sacrum needs clear separation from adjacent vertebrae on a clean background. Anatomical accuracy verified by SciePro's Medical Advisory Board.