Abstract: A fastener assembly for repairing fractured bone material includes a wire having a wire leading end for forming a bore through the bone material and a wire trailing end for extending beyond a near-side cortex of the bone material. The fastener includes a head portion having spaced-apart grooves defining cutting edges, a lower portion having threads, and an axial aperture therethrough for receiving the wire. The fastener is adapted to slide axially over the wire trailing end and be driven toward the wire leading end to countersink in the bone material. A driver including a driver body having an axially disposed aperture therethrough for accommodating said guide wire, and a driver head having fingers adapted to engage the spaced-apart grooves of the fastener head portion, is adapted to drive the fastener in the bone material.