Fig. 1From: Association between early sonographic findings and acetabular index at the age of 6 months: a prospective observational studyA Graf method. 1. Base line. 2. Bony roof line. 3. Cartilaginous roof line. B Femoral head coverage ratio; measured as a/b. 1. Base line. 2. Line parallel to base line and connected to the most lateral femoral head. 3. Line parallel to base line and connected to the most medial femoral headBack to article page