#$%^&*AU2014202013B220150716.pdf#####ABSTRACT An instrument for establishing orientation of a pelvic prosthesis comprises a tripod having an angularly adjustable guide rod on it. The tips of the legs define a 5 plane, and the guide rod is set by the surgeon to a defined orientation with respect to this plane on the basis of preoperative studies. In use, two of the legs of the instrument are positioned by the surgeon at defined anatomical locations on the pelvis (e.g., a point in the region of the posterior/inferior acetabulum and a point on the anterior superior iliac spine). The third leg then lands on the pelvis at a point determined by 10 the position of the first two points, as well as by the separations between the third leg and the other two legs. The separations arc adjustable, but are preferably fixed percentages of the separation between the first and second legs. The position of the guide rod then defines with respect to the actual pelvis the direction for insertion of a prosthesis.
