Patent ID: 7575572

Claim:
A device for delivering a substance to a bone, the device comprising: (a) a bone screw comprising two ends connected by a shaft, wherein the shaft is cannulated along at least a portion of its length; (b) one or more bone-screw fenestrations disposed along the cannulated portion of the bone-screw shaft; (c) an insert disposed inside the cannulated bone-screw shaft, wherein the insert comprises two ends connected by a shaft and is cannulated along at least a portion of its length; and (d) one or more insert fenestrations disposed along the cannulated portion of the insert between the two ends of the insert, wherein the insert is movable between: a first position wherein none of the one or more insert fenestrations align with the one or more bone-screw fenestrations such that at least a portion of the shaft of the insert substantially prevents material from entering the cannulated portion of the bone-screw through the one or more bone-screw fenestrations; and a second position wherein the insert provides a delivery pathway for the substance between at least one end of the bone screw and the at least one bone-screw fenestration.