Fig. 3.

Images of the lumbar spine, pelvis, and the hip. (A) The angle of lumbar lordosis (LL) was measured as an angle between line passing through the superior endplates of L1 and S1 by lateral radiograph of the lumber spine. (B) The pelvic incidence (PI) is defined as the angle between the line perpendicular to the sacral slope at its midpoint and the line connecting this point to the axis of the center of the right and left femoral heads by lateral radiograph of the pelvis. (C) On the mid-sagittal MRI, anterior center-edge (ACE) angle which is made by the intersection plane through the center of the femoral head.

PT, pelvic tilt; SS, sacral slope; GL, ground line.