Fig. 2A–B.

(A) The acetabular anteversion angle (AcAV) was determined in the axial plane passing through the femoral head center as the angle created by the intersection of a line connecting the anterior and posterior acetabular edges and a sagittal line. (B) The acetabular inclination angle (AI) was determined in the coronal plane passing through the femoral head center as the angle created by the intersection by a line connecting the superior and inferior acetabular edges and a horizontal line.