A medical instrument includes a tubular cutter extending along an axis and having a windowed outer sleeve and a moveable inner cutting sleeve. An ultrasound transducer is operatively coupled to the inner cutting sleeve in order to induce motion in the inner cutting sleeve to enhance cutting or resection of tissue by the inner cutting sleeve as it is reciprocated or otherwise moved past the cutting window. The instrument typically will include a motor drive configured to reciprocate and/or rotate the inner cutting sleeve relative to the windowed outer sleeve, usually at a reciprocation rate between 1 and 10 Hz.