A partial reverse shoulder prosthesis includes a humeral stem and a variable angle tray including a plate including a through hole including at least two cutouts oriented horizontally across from one another, and a repositionable variable angle stem occupying at least a portion of an internal cavity defined by the through hole and including a first washer including threads at least partially defining a first opening, a post at least partially occupying the internal cavity, and a pin insertable into the first opening and having a threaded head sized to engage the threads of at least one of the first washer and the post； wherein the wall of the internal cavity is sized to retain the first washer and at least a portion of the post.
