A system for treating bone, comprising: an elongated introducer (110A) with a flow channel (224a,224b) extending therethrough for introducing a bone fill material into an interior of a bone； a source of bone fill material (145) coupled to the flow channel (224a,224b) and configured to deliver a flow of bone fill material through the flow channel (224a,224b)； an energy source (125A) selectively coupleable to the bone fill material to alter the viscosity of the bone fill material； a sensor (235) configured to measure a characteristic of the bone fill material； and a controller (125B) configured to control the application of energy from the energy source (125A) to the bone fill material, wherein the controller (125B) includes algorithms that ramp-up and ramp-down power delivery from the energy source (125A) to the bone fill material in response to the measured characteristic of the bone fill material.
