Provided is an articulating cavitation device configured to cut cancellous bone wholly within a vertebra. The articulating cavitation device includes an end effector, having an extendable cutting element, configured to articulate relative to an insertion tube. Provided is a flowable material delivery system and method comprising one or a plurality of tentacles associated with an inflatable member. Provided is a minimally invasive cavity formation instrument for forming tissue cavities. The instrument includes an end effector having an aperture through which a cutting element is laterally extended and retracted.