Fig. 4

Decrease of postoperative axis deviation. Illustration of the decrease of postoperative deviation of mechanical leg axis in case of mal-angulation in counter-clockwise direction in frontal plane in subtrochanteric rotational osteotomy. With rotation over 20° a decrease of postoperative deviation of AP-projected mechanical leg axis could be observed. In green the preoperative hip-center, in red the hip-centers for each rotation, in black the AP-projected 0° varus/valgus axis, in grey the circle of relative rotation of the hip-center during rotational osteotomy