A surgical instrument (10, 100) configured to facilitate gripping and manual adjustment by a left-handed or righted-handed user. The surgical instrument includes a rod (11) having a first end (12a) attachable to a working end (13, 113) of the instrument via a mount (16). The rod has a second end (12b) coupled to a handle (14) having rotational directionality for gripping by a first hand of the user. The handle is rotatable about the rod so as to allow the user to adjust an angular displacement of the user's finger relative to the working end, and a locking member (20, 146) prevents rotation of the handle relative to the rod when the beveled indent is optimally located relative to the working end.