Fig. 3A–C.

The methods for measuring (A) the alpha angle, (B) lateral center-edge angle (LCEA), and (C) medial proximal femoral angle (MPFA) are shown. The alpha angle is formed between the line from the center of the femoral head to the middle of the narrowest part of the femoral neck and a line from the center of the femoral head to the point where the femoral head deviates from the circle contour. The LCEA is formed between a line from the center of the femoral head, vertically, and a line from the center of the femoral head to the lateral point of the acetabulum. The MPFA is formed between a line from the center of the femoral head to the proximal tip of the greater trochanter and a line from the proximal tip of the greater trochanter to the middle of the most distal part of the femur.