Fig. 2.

According to the anatomical features of 3D femoral neck model by means of software imageware12.1, and depending the shape of femoral neck surface, we fitted the most suitable cylinder whose axis was considered as the axial line of the normal femoral neck. Femoral neck anteversion plane was set by physiological-anatomical features. In the anteversion plane, the femoral neck axial line was rotated 8° in an anti-clockwise direction, by setting the femoral head centre as the centre of a circle. The rotated line was considered as the axial line of the femoral component