A forceps includes a housing, a curved waveguide, one or more movable members, and an end effector assembly. The housing includes one or more transducers configured to generate a mechanical vibration in response to energy transmitted thereto from an energy source. The curved waveguide extends from the housing and is configured to receive the mechanical vibration generated by the one or more transducers. The one or more movable members are positioned along the curved waveguide. The one or more movable members are configured to translate mechanical movement from the housing to the end effector assembly. The end effector assembly is disposed at a distal end of the curved waveguide and includes a movable jaw member pivotable between approximated and unapproximated positions relative to a distal end of the curved waveguide in response to movement of the one or more movable members.