Fig. 1A–C.

(A) The original phantom model consisted of a total hip prosthesis and a plastic model of the human proximal femur with six tantalum RSA bone-markers. (B) To achieve unrestricted motion of the stem, the femur model was replaced by a plastic tube with tantalum markers (open circles). Only the plastic tube model was applied in the current phantom study. For marker-based RSA, three implant markers (arrows) were attached by plastic studs in a configuration similar to that in clinical RSA-marked stems. (C) The implant construct was rigidly fixed to the base plate, forming the nonmovable portion of the phantom. The plastic femur/tube was distally attached to an x, y, z translation stage and a y rotation stage with micrometers (arrows) for highly controlled simulation of stem migration in relation to the surrounding bone.