Fatigue subcapital fracture of the femur after the removal of the hip plate in transtrochanteric rotational osteotomy.

We report two cases of fatigue subcapital fracture of the femur after the removal of the hip plate used for fixation in transtrochanteric rotational osteotomy for osteonecrosis. Two patients, a 42-year-old man and a 43-year-old man, underwent transtrochanteric rotational osteotomy, and bony union was achieved in both patients. However, fatigue subcapital fracture of the femur occurred in both patients 15 months after the removal of the hip plate. Transtrochanteric rotational osteotomy greatly changes the trabecular bone structure in the proximal femur, thus affecting the strength of the femoral neck. Therefore, for the trabecular bone to be remodeled and for the proximal femur to achieve sufficient strength, a sufficient period is necessary after complete bony union has occurred in the transtrochanteric lesion, before removal of the plate.