Measurement of acetabular component anteversion by the ischiolateral method. A line is drawn tangential to the opening of the acetabular shell connecting the two endpoints of the ellipse (AB). Another straight line is drawn along the long axis of the ischial tuberosity (CD). The anteversion angle (*) is measured between the perpendicular (EF) to a line drawn along the ischial tuberosity and the tangent to the acetabular shell (AB).