Patent ID: 8734457

Claim:
An instrument for use in a joint replacement procedure involving a bone having an intramedullary cavity, comprising: a trial head that corresponds to the head of an orthopaedic joint component having an upper curved surface that defines a polar axis and a lower surface, and a bore formed in the lower surface, the bore having a bore axis; a trial connector for connecting the trial head to a stem part of the orthopaedic joint component that is intended for location in the intramedullary cavity of the bone, wherein the trial connector can be fitted into the bore in the trial head at variable angular orientations; and a rotating indicator pivotally coupled about the polar axis, the rotating indicator being coupled to the trial connector such that a rotational position of the rotating indicator about the polar axis is indicative of a rotational position of the trial connector within the bore of the trial head; wherein the bore of the trial head is located eccentrically relative to the polar axis and the trial connector has a center and a recess located eccentrically relative to the center of the trial connector.