Sacrum, Anterior View

Description

Oriented in anterior (pelvic) view, the male sacrum appears as a triangular wedge between the right and left hip bones, its broad base articulating superiorly with L5 at the promontory and its apex tapering inferiorly toward the coccyx. The smooth facies pelvina carries four paired anterior sacral foramina arranged lateral to the fused vertebral bodies, while the transverse ridges (lineae transversae) mark the sites of sacral segment fusion. Laterally, the ala of the sacrum flares toward the auricular surfaces where it meets the ilium at the sacroiliac joints, and the acetabula sit inferolateral to this junction with the femoral heads aligned in the hip sockets. Spatially, the sacrum is medial to both iliac bones and posterior to the pubic symphysis. Clear landmarks. Anterior sacral anatomy matters when you need to relate pelvic bony corridors to the sacral nerve roots and pelvic viscera. The anterior sacral foramina transmit the ventral rami of S1 to S4, and their position relative to the sacral ala and sacroiliac joint is a key teaching point for sacral plexus formation and for understanding how pelvic fractures or sacroiliac disruptions can injure lumbosacral trunks. This view also supports preoperative planning for anterior approaches to the lumbosacral junction and for placing iliosacral screws, where identifying the promontory and lateral sacral margins helps avoid neurovascular and foraminal violation. Use this plate in gross anatomy and orthopaedic modules to orient learners to pelvic inlet landmarks, sacroiliac joint anatomy, and the relationship between the sacrum, lumbar vertebrae, and acetabulum, and in radiology teaching when correlating the pelvic surface with AP pelvis and inlet/outlet projections. It also suits surgical education materials on pelvic ring injury classification and safe zones around the anterior sacral foramina. Anatomical accuracy verified by SciePro's Medical Advisory Board.