Caudal Epidural Injection Done On The Human Sacrum

Description

Sacral hiatus access is centered in this illustration on the posterior aspect of the human sacrum, with the needle introduced in the midline between the sacral cornua at the inferior end of the sacral canal, just superior to the coccyx. The dorsal sacral crests and adjacent posterior sacral foramina provide bony landmarks lateral to the canal, while the needle trajectory aims cranially within the canal beneath the sacrococcygeal ligament toward the epidural space. Orientation stays fixed on the caudal sacrum so the relationship between the hiatus, canal, and surrounding dorsal surface anatomy remains unambiguous. Needle position is the visual emphasis. Caudal epidural injection is a standard route for epidural steroid delivery in lumbosacral radicular pain when interlaminar access is limited by prior surgery, stenosis, or difficult lumbar anatomy. The sacral hiatus is the practical entry point, yet it is also a frequent source of technical failure because of anatomic variation, ossified sacrococcygeal ligament, or a narrow canal, so the bony contours and midline corridor matter. A caudal approach also keeps attention on level awareness: the dural sac often terminates around S2, and staying caudal to that endpoint reduces risk of inadvertent dural puncture while still allowing cephalad spread within the epidural space. Pain medicine and anesthesiology educators can place this illustration beside procedural text on caudal epidural steroid injection, epidural catheter placement via the hiatus, and fluoroscopic or ultrasound landmarking of the sacral cornua. It also fits spine intervention manuals discussing cauda equina–related symptoms, contrast spread patterns in the sacral canal, and pitfalls such as intravascular injection via the sacral venous plexus. Anatomical accuracy verified by SciePro's Medical Advisory Board.