Fig. 4.

(A) The acetabular anteversion angle was quantified as the angle formed by a line connecting the anterior and posterior edges of the acetabulum and the y-axis at the transverse section through the femoral head’s center. (B) The acetabular inclination angle was quantified as the angle formed by a line connecting the superior and inferior edges of the acetabulum and the x-axis at the coronal section through the femoral head’s center. AcAV = acetabular anteversion angle; AI = acetabular inclination.