Patent ID: 7717947

Claim:
A bone screw, comprising: a screw head and a threaded shank, wherein an axial bore into which a plurality of radial bores open which are set at a distance from each other, extends through the threaded shank, wherein said axial bore is open at the screw head side end and wherein the radial bores are also open at the radially outer end, wherein the axial bore is closed in an axial direction in the area of the end of the threaded shank that is located opposite the screw head; an adapter that can be fitted onto the screw head and comprises an axial bore aligned with the axial bore of the threaded shank when the adapter is in the fitted state, the adapter comprising a holder having an inner circumferential shoulder for taking up a lower syringe or cartridge end in a tight manner inside the holder; wherein the adapter comprises an upper end and a lower end facing the screw head and the holder comprises a tubular portion extending from the upper end to the inner circumferential shoulder, wherein the inner circumferential shoulder is a tapered portion that converges inside the holder from the tubular portion toward the lower end of the adapter the tapered portion having a greater slope than an adjacent portion of the tubular member; and wherein the adapter comprises a further circumferential shoulder having a tapered cross section that engages an outer surface of the screw head in the fitted state.