Disclosed is a prosthetic augment designed to reconstruct a lateral tuberosity shape of a humerus in a subject having proximal bone loss that includes a humeral adapter tray configured to connect a humeral liner of a reverse shoulder prosthesis to a humeral stem of the reverse shoulder prosthesis and an augment member having a first face adapted for contacting the humeral stem of the reverse shoulder prosthesis and a second face adapted for contacting an underside of a muscle, wherein at least a portion of the second face includes a bulbous surface adapted to alter a wrapping angle of the muscle around the lateral tuberosity, and wherein the second face has a radius of curvature selected from one of a constant radius of curvature or a variable radius of curvature.
