Medial Part Of The Sacrum

Description

Sacral midline anatomy dominates this view, centering on the fused S1 to S5 vertebral bodies that form the triangular sacrum between the lumbar spine and coccyx. Superiorly, the sacral promontory marks the anterior projecting lip of S1, while the median sacral crest tracks inferiorly along the posterior surface as the fused remnants of the spinous processes. The sacral canal lies immediately deep to this midline ridge, widening toward the inferior end where the sacral hiatus opens between the sacral cornua. Midline landmarks are unambiguous. Clinically, these structures matter whenever you need reliable surface and bony reference points in the pelvis and lower spine, from neuraxial procedures to trauma assessment. The relationship between the sacral hiatus, cornua, and distal sacral canal is the key anatomy for caudal epidural access, and it is also where congenital nonfusion (spina bifida occulta) or degenerative change can alter the contour and narrow the approach window. The crisp separation of cortical bone from the canal space in a fixed perspective supports straightforward correlation with mid-sagittal CT or MRI when teaching sacral fractures, transitional anatomy at L5 to S1, or postoperative landmarks after lumbosacral instrumentation. Use this illustration in gross anatomy and osteology teaching sets, in anesthesia or pain-medicine courseware covering caudal epidurals, and in orthopedic and neurosurgical publications that need a midline sacral reference without distracting lateral pelvic detail. Anatomical accuracy verified by SciePro's Medical Advisory Board.