A bone chisel for creating a protrusion bearing cruciate ligament attachments from an upper side of a tibia head, which has a blade that encloses an area of a projection in a U-shape to a front with a transverse wall and to a side with side walls, and which has a cutter. A guide rod extended parallel to a driving direction of the bone chisel is mounted on a side of the bone chisel formed by the transverse wall, which guide rod is displaceably mounted in a direction of the guide rod in a guide head, which can be affixed on a front side of the tibia head.
