A system for fixating fractured bones comprising a bone plate (1) and bone screws. The bone plate includes oblong holes (4) with hole portions that are free from any barrier for a screw shaft moved between the hole portions. The hole portions also include support structures for the screw heads and a sloping guideway between the hole portions. One of the hole portions has an upper segment (50) with cylindrical thread on an arc of about less than 180, preferable 175 or most preferable 179 degrees and to which the guideway is sloping. An adapted screw (20) with cylindrical thread, when mounted in the bone plate, minimizes the gap between the threads.
