In one general aspect, various embodiments are directed to an ultrasonic surgical instrument that comprises a handpiece housing that rotatably supports an ultrasonic transducer assembly therein that may be selectively rotated by various motor configurations. Various slip ring arrangements are disclosed for supplying ultrasonic electrical signals and motor drive signals from a control system. Various forms of blade and cutting implements are disclosed for attachment to the ultrasonic transducer assembly such that such implements may be selectively rotatable within a hollow outer sheath. Vacuum may be applied to the cutting implement or through the outer sheath to draw tissue through an opening in the sheath and into contact with the cutting implement.