A method of harvesting bone marrow, including percutaneously introducing a multi-lumen cannula into a cancellous bone, applying suction through a first passage defined in a first lumen of the cannula, injecting a thick flowable material into the bone from a second passage in a second lumen of the cannula, extruding the thick flowable material through a distal end of the cannula into the cancellous bone in order to displace the bone marrow and other bone fluids, the suction applied through the first passage providing a hydraulic force guiding the displaced bone marrow and collecting the displaced bone marrow for a therapeutic or diagnostic purpose. A thick flowable material for use in harvesting bone marrow in the cancellous portion of a bone and a method for percutaneously preparing a bone with a multi-lumen cannula and an inflatable device are also discussed.
