The Hip Bone In Medial View Showing The Posterior Superior Iliac Spine

Description

Rotating through a medial view of the os coxae, the animation brings the posterior superior iliac spine (PSIS) into relief at the posterior end of the iliac crest, just superior to the auricular surface for the sacrum. As the bone turns, the iliac fossa occupies the anterior and medial aspect of the ilium, while the greater sciatic notch and posterior border sweep inferiorly toward the ischial spine. The sequence clarifies how the PSIS sits posteromedial to the anterior superior iliac spine and superior to the posterior inferior iliac spine, anchoring the transition from crest to sacroiliac region. Palpation and landmarking drive the value of this view. Clinicians use the PSIS as a surface marker for the level of S2 and as a reference point when assessing pelvic obliquity, leg length discrepancy, and sacroiliac joint pain patterns, and it guides needle placement during fluoroscopic or ultrasound oriented sacroiliac joint injections where bony contours limit access. Motion helps here: small changes in rotation can make the auricular surface, preauricular sulcus (when present), and iliac tuberosity appear or disappear, explaining why the landmark can feel inconsistent between patients. Use it in gross anatomy teaching when introducing the innominate bone from the medial aspect, or in osteology labs that emphasize sacroiliac joint anatomy and palpation based surface anatomy. It also suits orthopedic, sports medicine, and pain management presentations discussing SI joint dysfunction, posterior pelvic landmarks, and safe trajectories for posterior approach injections. Anatomical accuracy verified by SciePro's Medical Advisory Board.