An instrument for use in a joint replacement procedure includes a trial head that corresponds to the head of an orthopaedic joint component having an upper surface defined by a curved surface and a bore formed in a lower surface and a trial connector for connecting the trial head to a stem part of the orthopaedic joint component which is intended for location in the intramedullary cavity of a bone. The trial connector can be fitted into the bore in the trial head at a variable angular orientation.