Gross Anatomy of the Posterior Female Sacral Region

Description

Centered in the posterior pelvis, the sacrum sits inferior to L5 and superior to the coccyx, its dorsal surface tapering caudally between the paired iliac bones. Along the midline, the median sacral crest marks fused spinous processes, flanked by intermediate and lateral sacral crests that overlie the dorsal sacral foramina and the posterior sacroiliac ligament complex. Laterally, the auricular surfaces meet the ilia at the sacroiliac joints, with the posterior superior iliac spines serving as palpable landmarks superior and lateral to the sacral base. Bony landmarks matter here. Posterior sacral anatomy is where posterior pelvic ring stability becomes clinically concrete, since disruptions at the sacroiliac joint or sacral ala commonly drive pain and mechanical instability after falls, childbirth-related trauma, or high-energy pelvic fractures. The dorsal sacral foramina transmit posterior rami, and irritation or entrapment can refer pain into the buttock and posterior thigh, a pattern often mistaken for lumbar radiculopathy in clinic. Inferiorly, the sacral hiatus and sacral cornua guide caudal epidural access, while the adjacent coccyx and sacrococcygeal junction frame the site of coccydynia and coccygeal fracture. Use this posterior female sacral region view for teaching osteology and surface anatomy in a gross anatomy or physical diagnosis course, where students need to correlate the PSIS and sacral crests with palpable back landmarks. It also fits orthopedic trauma, pain medicine, and radiology publications discussing posterior pelvic ring fixation trajectories, sacroiliac joint injections, or caudal epidural technique. Anatomical accuracy verified by SciePro's Medical Advisory Board.