A surgical operating instrument includes a handle, a first driving shaft operably connected with the handle, a second driving shaft, and a gear assembly. The gear assembly includes a first gear member received on the first driving shaft, a second gear member slidably received on the second driving shaft, and a lever member. The lever member is operable to place the second gear member into engagement with the first gear member thereby coupling the second driving shaft with the first driving shaft to provide a first operating mode wherein the handle operates to rotate both the first and second driving shafts, and place the second gear member out of engagement with the first gear member thereby decoupling the second driving shaft from the first driving shaft to provide a second operating mode wherein the handle operates to rotate solely the first driving shaft.