Fig. (1) (a) At the first visit, a plain radiograph of the right hip showed joint space narrowing (KL grading II). A laddering-shaped deformity in the right lateral proximal femoral head and fracture-like line were observed (white arrow). (b) Eight months after onset, a plain radiograph revealed increased joint space narrowing, a band around the necrotic area, and a concave shape to the right femoral head. (c) The necrotic region of the right femoral head became noticeably worse a year after onset. (d) The right femoral head had collapsed at 3 years after onset. (e) A recent radiograph showed progressive destruction of the right femoral head and the remaining joint line exhibited osteosclerotic change. Note that the patient did not report any joint pain.