Hip Bone Showing The Lunate Surface Of Acetabulum, Inferior View

Description

Acetabulum dominates this inferior view of the hip bone, with the lunate surface forming a smooth, horseshoe-shaped articular band along the acetabular rim. Inferiorly, the non-articular acetabular notch interrupts the ring, bridging toward the pubic and ischial components and indicating the typical location of the transverse acetabular ligament in life. Medial to the lunate surface lies the acetabular fossa, a recessed non-articular area, while the peripheral rim provides the bony attachment margin for the acetabular labrum. Bony landmarks around the socket orient the viewer to the pelvis, with the ischium posteroinferiorly and the pubis anteroinferiorly contributing to the cup. Lunate surface morphology matters because it defines the true weight-bearing contact area with the femoral head, the region that degenerates and remodels in hip osteoarthritis and the region surgeons aim to restore in acetabular component positioning during total hip arthroplasty. Subtle changes in coverage and rim contour also underpin femoroacetabular impingement patterns, where pincer-type overcoverage and labral pathology often localize near the anterosuperior rim but are understood relative to the full circumferential acetabulum. Orientation from an inferior perspective also helps when teaching acetabular fractures, since disruption near the notch and inferior rim can alter joint congruence while sparing the fossa. Orthopaedic anatomy courses and arthroplasty training manuals can pair this illustration with femoral head images to explain congruency, load transfer, and labral attachment along the acetabular rim. It also fits radiology and trauma teaching sets when correlating pelvic CT reconstructions with the acetabular notch, inferior rim fragments, and patterns of articular involvement. Anatomical accuracy verified by SciePro's Medical Advisory Board.