Lateral Part Of The Sacrum, Posterior View

Description

Sacral ala and the adjacent dorsal surface dominate this posterior-lateral view of the sacrum. Laterally, the roughened sacral tuberosity sits posterior to the auricular area for the ilium, while medially the intermediate and lateral sacral crests border the region where the posterior sacral foramina open toward the dorsal sacral rami. Superiorly the ala broadens toward the base of S1, and inferiorly the surface narrows toward the lower sacral segments as the bone approaches the coccygeal end. Texture matters here. That pitted, irregular topography is the footprint of strong ligamentous and muscular attachments, most importantly the posterior sacroiliac ligament complex and fibers of gluteus maximus arising from the dorsal sacrum, a relationship that helps explain why posterior pelvic pain can localize near the posterior superior iliac spine and track toward the sacroiliac joint. Palpation and injection planning often rely on bony landmarks that are not smooth, and the fixed posterior perspective makes the contrast between the smoother articular region and the coarse ligament-bearing zone immediately apparent. For surgeons and pain physicians, this is the terrain encountered when approaching the sacroiliac region from behind, with the posterior sacral foramina reminding you where dorsal rami and lateral branches travel. Use this illustration in gross anatomy and osteology teaching to differentiate the sacral ala from the dorsal crests, and in orthopedic, spine, and pain-management materials discussing sacroiliac joint dysfunction, posterior sacroiliac ligament strain, and sacral landmark-guided procedures. Anatomical accuracy verified by SciePro's Medical Advisory Board.