Fig. 4. Anteroposterior radiographs of the left hip joint in a 47-year-old female. (A) The preoperative radiograph shows moderate joint space narrowing with subchondral cyst in the femoral head (Tönnis grade 2). (B) The postoperative radiograph shows improvement of acetabular coverage over the femoral head. (C) The postoperative radiograph obtained 7 years after rotational acetabular osteotomy shows progression of osteoarthritis. (D) Total hip arthroplasty was performed 7.5 years after the index surgery due to progressive osteoarthritis.