Fig. 3.

(a) and (b) The acetabular component is forward projected from an initial 3-D pose onto the respective x-ray image plane. (c) and (d) The surgeon moves the cup until satisfied with the alignment in both views. The x-ray images shown here are acquired from a dry pelvis phantom encased in gelatin. (e) A cubic visual marker is placed near the phantom but outside the x-ray field of view to track the C-arm.