US Patent 11490832 Method and apparatus for determining acetabular component positioning

An instrument for establishing orientation of a pelvic prosthesis comprises a hub, a first arm attached to and extending from the hub, and a second arm attached to and extending from the hub. The first and second arms define a nominal plane of the apparatus, and may extend from the hub at an angle relative to each other. Distances between the first and second legs and between the first and third legs are adjustable. The first, second, and third legs have tips, and the tips of the first, second, and third legs define a plane having a predefined geometric relationship to the nominal plane of the apparatus.