Posterior Perspective of the Pelvic Bones

Description

Viewed from posterior, the paired hip bones (os coxae) frame the midline sacrum, with the iliac crests sweeping laterally to the posterior superior iliac spines (PSIS) and posterior inferior iliac spines (PIIS). Inferior to the posterior ilium, the ischial bodies and ischial tuberosities occupy the posteroinferior pelvis, flanking the greater and lesser sciatic notches that lead into the greater and lesser sciatic foramina. Proximally, the femoral heads seat in the acetabula, and the femoral necks angle anteromedially from the visible proximal shafts while the coccyx tapers inferior to the sacral apex. Posterior bony landmarks drive both surface anatomy and operative planning. The PSIS corresponds to the posterior dimples and is a practical reference for approximating the S2 level, relevant when planning caudal epidural access and when interpreting sacroiliac joint pain patterns. This perspective also clarifies the relationship of the greater sciatic notch to the ischial spine and sacrospinous ligament, the corridor used by the sciatic nerve after it exits the pelvis, and a frequent site implicated in deep gluteal syndrome and posterior hip approaches. Use this plate in gross anatomy labs to orient students to posterior pelvic palpation points, the sacroiliac joints, and the sex-specific morphology of the male pelvis. It also fits orthopedic and sports medicine teaching on posterior hip dislocation mechanics, hamstring origin injuries at the ischial tuberosity, and fluoroscopic landmarking for SI joint injections. Anatomical accuracy verified by SciePro's Medical Advisory Board.