Fig. 2

Schematic diagram showing the measurement of the component parameters. (A), the abduction angle of the cup was defined as the angle formed by the parallel line of the connecting the two teardrops and the line connecting the upper and lower ends of the open plane of the cup on an anteroposterior radiograph of the pelvis. (B), the anteversion angles of the cup defined as the angle between a line connecting the lateral anterior and posterior margins of the acetabular component and the sagittal plane defined as the plane perpendicular to a line connecting two identical points on either side of the pelvis on an axial plane of 2-dimensional computed tomography. (C), the anteversion angles of the femoral component were defined as the angle between a line of the head-neck axis and the coronal plane defined as the plane perpendicular to a line connecting two identical points on either side of the pelvis on an axial plane of 2-dimensional computed tomography