Patent ID: 7252671

Claim:
A method comprising accessing cancellous bone through a percutaneous access path in soft tissue, forming a cavity in cancellous bone including providing a cavity forming tool, advancing the cavity forming tool through the percutaneous access path into cancellous bone, and manipulating the cavity forming tool to form the cavity, providing an instrument for introducing a filling material into the cavity comprising a first chamber section having a first volume and a second chamber section having a second volume less than the first volume, the first and second chamber sections being in series relation with the second chamber section being distal of the first chamber section, inserting at least a portion of the second chamber section through the percutaneous access path, and delivering a first volume of bone filling material into the cavity through the subcutaneous access path by advancing a first plunger through the first chamber section to express filling material from the first chamber section through the second chamber section into the cavity, the first plunger being too large to enter the second chamber section, delivering a second volume of bone filling material into the cavity through the subcutaneous access path by advancing a second plunger through the second chamber section to express filling material residing in the second chamber section into the cavity, the second volume being less than the first volume.