A bone plate system is disclosed which includes a bone plate having at least one plate hole, at least one pin adapted to be disposed in the at least one plate hole, and a polymer component disposed between the at least one pin and the bone plate. The polymer component includes a polymer that may be melted through the application of ultrasonic energy. The at least one pin is constructed of a material that will not melt under such application of ultrasonic energy. The re-solidified polymer component creates a bond between the at least one pin and the bone plate to provide a more rigid and secure mating therebetween, and to at least substantially prevent backout of the at least one pin with respect to the bone plate. A method of implanting the bone plate system is also disclosed.