Methods The aiming device was designed on the principle of a line crossing any point on a spherical surface and perpendicular to it must cross the sphere center, which enables the surgeon to locate the ligamentous attachment of cruciate ligament precisely for reconstruction. 方法根据经过球面上任何一点垂直于球面的线均经过球心的基本原理,设计出用于重建十字韧带手术时韧带附着点定位的瞄准器。