US Patent 9271769 Bone plate and fixation system comprising a bone plate

A bone plate and to a fixation system comprising two types of bone screws. The bone plate has two intersecting stepped round holes which are different in size and in the upper regions of which a circumferential rib extends. The upper region of the smaller round hole is designed to slidably guide a bone screw having a partially spherical heads and a screw having a thread or conical head. The lower region of the larger round hole is used to support a conical head.