mplant of FIG. 7 uncoupled from the insertion instrument. [0023]FIGS. 11A and 11B are a plan view and side view, respectively, of a distal portion of another embodiment trial instrument. [0024]FIGS. 12A and 12B are a plan view and side view, respectively, of a distal portion of another embodiment trial instrument. [0025]FIGS. 13A and 13B are a plan view and side view, respectively, of a distal por