A surgical implant planning computer positions an implant device relative to a bone of a patient. An initial image of a bone is obtained. An initial location data structure is obtained that contains data defining mapping between locations on the implant device and corresponding locations relative to the bone in the initial image. A target image of the bone of the patient is obtained. A transformation matrix is generated that transforms a contour of a portion of the bone in the initial image to satisfy a defined rule for conforming to a contour of a corresponding portion of the bone in the target image. A transformed location data structure is generated based on applying the transformation matrix to the initial location data structure. A graphical representation of the implant device is displayed overlaid at locations on the target image of the bone determined based on the transformed location data structure.
