Anatomical Structure Of The Posterior Sacral Hiatus

Description

Posteriorly, the sacrum is shown in anatomical position with the sacral hiatus highlighted at the inferior end of the sacral canal. The animation tracks along the median sacral crest and paired intermediate sacral crests before settling on the inverted U-shaped defect created by nonfusion of the laminae of S5 (and often S4), bordered laterally by the sacral cornua. As the sequence rotates and tightens its field of view, the relationship of the hiatus to the sacral apex, coccyx, and dorsal sacral foramina becomes clear. Bony landmarks stay constant while the camera motion clarifies depth and orientation. Clinically, this is the entry point for caudal epidural anesthesia and analgesia, where palpation of the sacral cornua guides needle placement through the sacrococcygeal ligament into the epidural space. Small variations in the shape, height, and position of the sacral hiatus, along with a narrow canal or an absent hiatus, account for failed caudal blocks and a higher risk of subperiosteal injection. Animation helps because you can watch the landmark-based approach in sequence, from identifying the posterior superior iliac spine line to dropping inferiorly to the apex and locating the cornua, rather than trying to infer the path from a single still. Use this asset for anesthesiology teaching on caudal epidural technique, gross anatomy and osteology modules on the pelvis and vertebral column, and clinical skills content that links surface anatomy to sacral canal access; it also suits patient-facing education when explaining why needle trajectory and bony variation matter. Anatomical accuracy verified by SciePro's Medical Advisory Board.