Transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: relation between radiographic features and secondary collapse

We concluded that we should be cautious when the newly established healthy weight-bearing area exhibits this beak shape, even if its extent in the weight-bearing area is large, because of the higher risk of postoperative secondary collapse. In such cases, alteration of the after-treatment program (e.g., prolonging the non-weight-bearing period) should be considered.