Avascular necrosis (AVN), also known as osteonecrosis, is a condition caused by interruption of blood supply to the bone, most commonly affecting the femoral head. Reduced blood flow leads to bone ischemia, necrosis, collapse, and secondary osteoarthritis if not diagnosed early. 📌 Radiographic Progression Explained: Normal Hip X-ray Smooth, round femoral head Preserved joint space and trabecular pattern AVN – Grade I Normal appearance No sclerosis, lucency, or collapse Femoral head contour pres