PROBLEM TO BE SOLVED: To provide a lug screw which can be fixed in a single direction of a screwing direction in a short time without requiring special dedicated techniques, and can easily achieve stable bonding and detaching of bones without causing loose with a relatively small force.SOLUTION: In a structure for fixing a nail and a lug screw by screwing them, the lug screw includes a double thread screw having high static stability on the front end, a double sided edge for screwing and unscrewing and three or more leaf-like concave surface grooves in the rear end surface to prevent thread strip for the screwing tool the lug screw further includes a guide key to be smoothly coupled to the nail and the lug screw further includes a sleeve capable of rotating around the lug screw and being locked.COPYRIGHT: (C)2014,JPO&INPIT【課題】特殊な専門技術を必要とせずに、短時間にねじ込み方向の一方向だけで固定でき、容易に比較的小さい力で、緩みなく安定的に骨の接合と脱着ができるラグスクリュウを提供すること。【解決手段】ねじ込みによりネイルとラグスクリュウとを固定する構造にあって、ラグスクリュウが先端に静止安定性の高い二条ねじとねじ込みと巻き戻しのための両面刃先と後端面にねじ込み工具のためのナメ防止の三葉以上の葉形凹面溝を備えると共に、ネイルに滑り結合するガイドキーを備えてさらにラグスクリュウに対して回転できてロックできるスリーブを備える構造を備えることを特徴とする。【選択図】図8
