Fig. 1

Initial radiographic and CT images with follow up imaging demonstrating AVN. Images from a 26-year-old male (top row, a, c, e, g) and a 36-year-old male (b, d, f, h) each with Neer four-part fractures were obtained including a, b initial frontal radiograph, c, d axial CT image, e, f post-ORIF radiograph and g, h evidence of osteonecrosis. g An attenuated linear shell of cortex with underlying lucency consistent with subchondral collapse due to AVN is present at 12 months after treatment (block arrow). h Subtle, circumscribed sclerosis adjacent to a focal lucency (block arrow) is consistent with AVN without collapse. The dashed line (c, thin arrow) indicates the outer margin of the 100 kVp source