A surgical instrument includes a shaft extending distally from the housing, an end effector assembly disposed at a distal end of the shaft and configured to supply energy to tissue to treat tissue, a knife slidably disposed within the shaft and movable relative to the end effector assembly between a retracted position and an extended position, and a trigger operably coupled to the housing. The trigger is selectively activatable from a neutral position to a laterally pivoted position to supply energy to the end effector assembly and is selectively actuatable from a distal position to a proximally pivoted position to deploy the knife from the retracted position to the extended position. In the laterally pivoted position of the trigger, actuation of the trigger is inhibited. In the proximally pivoted position of the trigger, activation of the trigger is inhibited.