Fig. 4From: Standard radiographic values for the acetabulum in Japanese adolescents: a cross-sectional studyTönnis angle. To determine the Tönnis angle, a line is drawn connecting the inferior and lateral aspects of the sourcil. A second line is drawn parallel to the transverse axis of the pelvis and through the inferior aspect of the sourcil. The Tönnis angle is created by the intersection of these two linesBack to article page