Fig. 6From: Standard radiographic values for the acetabulum in Japanese adolescents: a cross-sectional studyAcetabular head index. The acetabular head index is defined as the percentage calculated by dividing (A) the horizontal distance of the femoral head from the medial margin to the edge of the acetabulum by (B) the total horizontal width of the femoral head. The formula is A/B × 100Back to article page