An electrosurgical instrument includes a housing and a shaft coupled to the housing. The shaft has an end-effector assembly at a distal end thereof. The end-effector assembly includes opposing first and second jaw members. One or both of the first and second jaw members is movable from a first position wherein the first and second jaw members are disposed in spaced relation relative to one another to at least a second position closer to one another wherein the first and second jaw members cooperate to grasp tissue therebetween. The first jaw member includes a first tissue-engaging surface. The second jaw member includes a second tissue-engaging surface and a protruding element extending therefrom. The second jaw member is configured to receive and transmit a mechanical vibration to provide a mechanical cutting action on tissue disposed between the first and second tissue-engaging surfaces.
