Abstract: A surgical instrument including a handle adapted to releasably engage a shaft mounting a tool having relatively moveable parts. The handle is provided with an actuating structure which includes a trigger arm selectively moveable relative to the handle to cause concurrent movement of the relatively moveable parts of the tool. The actuating structure may include a locking mechanism for releasably fixing the position of the handle relative to the handle, thus releasably fixing the relative positions of the moveable parts of the tool. The handle is also provided with an operating mechanism which is operatively coupled to the tool to selectively rotate the tool relative to the handle. The operating mechanism may be motorized. The operating mechanism may include a control circuit which can be programmed to activate the motor to rotate the tool through specific intervals of displacement is a chosen direction according to selective manipulations of control switches.