Anatomical Characteristics Of The Sacral Horn

Description

Sacral cornua (cornua sacralia) project inferiorly from the dorsolateral margins of the sacral hiatus, flanking the terminal opening of the sacral canal on the posterior surface of the sacrum. Each horn represents the elongated inferior articular process of S5, positioned lateral to the midline median sacral crest and superior to the dorsal aspect of the coccyx at the sacrococcygeal junction. Adjacent landmarks that typically share the frame include the intermediate sacral crests, the posterior sacral foramina arranged superiorly, and the broad posterior sacral ala tapering toward the apex. Palpable sacral horns matter because they bracket the sacral hiatus, the surface entry point for caudal epidural anesthesia and steroid injection, where needle placement depends on reliably locating the bony margins rather than soft-tissue cues. Small, asymmetric, or partially ossified cornua can correlate with technical difficulty and failed caudal access, and they help explain why ultrasound or fluoroscopy is often chosen when surface anatomy is equivocal. Bony relief is the teaching point. The fixed perspective supports orientation to the posterior sacrum by keeping the hiatus, cornua, and surrounding crests in a single spatial read. Use this illustration in regional anatomy teaching on the pelvis and vertebral column, in anesthesia or pain-medicine manuals covering caudal epidural technique, and in orthopedic or spine texts describing posterior sacral landmarks and variations at S4 to S5. It also suits patient-facing procedural education when you need a precise bony reference for where the needle targets relative to the sacral canal and coccyx. Anatomical accuracy verified by SciePro's Medical Advisory Board.