Lateral Perspective of the Sacrum Bone

Description

Seen from the lateral aspect, the sacrum sits inferior to L5 at the lumbosacral junction and superior to the coccyx, with the fused sacral bodies forming a wedge that slopes anteroinferiorly into the pelvic cavity. Along the posterolateral margin, the auricular surface and adjacent sacral tuberosity mark the articular and ligamentous interface with the ilium at the sacroiliac joint. Posteriorly, the median sacral crest and dorsal sacral foramina align with the continuation of the vertebral canal as the sacral canal, terminating at the sacral hiatus near the apex. This side-on presentation matters when you need to understand load transfer from the lumbar spine to the pelvic ring and how small changes in sacral slope affect sagittal balance. The auricular surface is a practical landmark for correlating sacroiliac joint pain patterns, inflammatory sacroiliitis, and the joint’s limited but clinically meaningful nutation and counternutation. It also supports teaching around procedures that depend on posterior sacral landmarks, including caudal epidural access through the sacral hiatus and safe corridors for iliosacral screw fixation in pelvic ring trauma. Use this artwork in gross anatomy and musculoskeletal modules to reinforce the three-dimensional relationship between the lumbosacral junction, sacroiliac articulation, and coccygeal attachment points, and in radiology or orthopaedic texts when paired with lateral pelvic radiographs or sagittal CT/MRI reconstructions. A strong fit for patient-facing materials on sacroiliac dysfunction and for surgical education on posterior pelvic approaches. Anatomical accuracy verified by SciePro's Medical Advisory Board.