Fig. 3.

The position of the three-dimensional axis of the femoral neck was analysed in the general geometry of the femur as illustrated here in a frontal view (A) and a sagittal view (B). Both the distance of the centre of the femoral head and the femoral neck axis (d1), and the distance of the shaft axis and the femoral neck axis (d2) were calculated. (A), femoral neck axis; (D), femoral shaft axis; O, centre of the femoral head; P, pseudo-intersection between the femoral neck axis and the shaft axis.