Bone screw includes a screw head which is composed of a screw shaft extending longitudinally along the screw axis, so that it can be connected releasably to the surgical tool and extending from the proximal end of the screw shaft. A through hole extending through the screw head and defining a hole axis also includes a through-hole axis intersect at an acute angle a with the screw shaft, the through-hole, the bone screw is adapted to receive in a in a second screw and tapered toward the second end which is opened to the outer surface of the screw head from the first end of the proximal end of the screw head and the. [Selection] Figure Figure 1骨スクリューは、スクリュー軸に沿って縦方向に延びるスクリューシャフトと、スクリューシャフトの近位端から延び且つ手術道具に解放自在に連結できるように構成されたスクリューヘッドとを含む。骨スクリューは、貫通孔軸を規定し且つスクリューヘッドを通って延びる貫通孔も含み、この貫通孔軸はスクリュー軸と鋭角aで交差し、貫通孔は、第2スクリューを中で受け止めるように適合され且つスクリューヘッドの近位端の第1端からスクリューヘッドの外面に開けられた第2端に向って先細りする。【選択図】図1
