Device for osteosynthesis

A bone plate system, comprising a bone plate having a bottom surface for contacting bone, an upper surface and at least one through hole extending from the bottom surface to the upper surface, the through hole having a central axis and an at least partially polygonal cross-section orthogonal to the central axis;

• and a bushing within the through hole, the bushing including a central bore designed to receive a bone screw, the bore having a longitudinal axis, and a peripheral outer surface configured and dimensioned to be in contact with at least a portion of the interior surface of the through hole;
• and at least one bone screw having a threaded shaft for anchoring within the bone, a longitudinal screw axis, and a screw head configured and dimensioned for insertion into the central bore of the bushing wherein the bushing is configured and dimensioned to be radially compressible and radially expansible, and a cross section of the bushing orthogonal to the longitudinal axis of the bushing is shaped substantially the same as the cross section of the through hole so that the bushing is secured against rotation relative to its longitudinal axis while remaining pivotally adjustable relative to the bone plate to vary an angle of the longitudinal axis of the bore with respect to the central axis of the through hole.