1. A method for determining a location of a frontal pelvic plane of a pelvic bone, comprising: ascertaining a position of a pubic point of the pelvic bone; generating at least one x-ray recording of the pelvic bone; ascertaining a straight line in the at least one x-ray recording that passes through the pubic point and a contour of the pelvic bone; ascertaining the location of the frontal pelvic plane from a rear-projection of the straight line; and outputting the ascertained location of the frontal pelvic plane.