The ornamental design for a surgicalinstrument, as shown and described.
FIG. 1 is a perspective view of a surgical instrument showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. In addition, the unshaded surface that directly adjoins the claimed solid line edge forms no part for the claimed design.