Figure 1

Computer-aided model of the acetabular component: the cross-sectional dimensions and the 3D computer model of the acetabular component of the new THR. (Units: mm and degrees). An acetabular prosthesis coordinate system (APCS) of the acetabular component was defined with three orthogonal axes. The Z-axis of the APCS was normal to the ventral opening surface, the X-axis was parallel to a line connecting the mid-points of the junctions between the ventral and dorsal opening surfaces, and the Y-axis was obtained as the cross-product of the Z-axis and X-axis.