Fractured Sacrum, Anterior View

Description

Centered in the pelvic inlet, the sacrum is presented from the anterior (pelvic) aspect, with the promontory and S1 vertebral body superiorly and the apex tapering inferiorly toward the coccyx. The paired sacral alae flare laterally toward the sacroiliac joints, while the anterior sacral foramina punctuate the concave surface in vertical rows medial to the alae. A transverse fracture line, highlighted in red, tracks across the upper sacral segments near the level of the superior articular processes and adjacent sacral foramina, interrupting the normal transverse ridges that mark fusion of the sacral vertebrae. Fracture anatomy is the focus. Anterior sacral fractures matter because the pelvic surface is where fracture propagation can be mapped against the foraminal corridors that transmit the ventral rami of S1 to S4, and because involvement of the upper sacrum often accompanies pelvic ring trauma at the sacroiliac complex. In high-energy mechanisms (motor vehicle collision, fall from height), a transverse component at S1 to S2 raises concern for spinopelvic dissociation and associated neurologic deficit, while in low-energy insufficiency fractures the sacral ala is a common site that can mimic lumbar radiculopathy. Correlating the fracture line with the foramina and ala also supports discussion of Denis fracture zones and the risk gradient for sacral nerve injury and bowel, bladder, or sexual dysfunction. Use this artwork in orthopaedic trauma lectures on pelvic ring injuries, neurosurgery teaching on sacral nerve root vulnerability, or radiology correlations when explaining why CT in axial and coronal planes clarifies anterior sacral fracture extent better than plain pelvic radiographs. It also suits textbook figures on lumbosacral junction anatomy and medicolegal graphics describing mechanism and level of injury in an adult male pelvis. Anatomical accuracy verified by SciePro's Medical Advisory Board.