Patent ID: 8556947

Claim:
A device for fixation of a bone fracture by use of ultrasonic energy, comprising: a bone screw comprising a shank having a first threaded end portion and having along its longitudinal center line an axial through bore having a first bore portion with a first diameter and a second bore portion with a second diameter, wherein the first diameter is larger than the second diameter and the second bore portion is adjacent the first threaded end portion, and a step in the bore between the first and the second bore portions; a metal insert having a disk-shaped first end having a diameter smaller than the first diameter and larger than the second diameter, the metal insert having a second end having a diameter smaller than the diameter of the first end of the metal insert; and a polymer pin for insertion into the first bore portion of the bone screw with the first diameter, the polymer pin having a leading end with a recessed bore for receiving the second end of the metal insert, the recessed bore having an end wall defining a base of the recessed bore, the metal insert second end having an end face contacting the end wall of the base of the recessed bore for the transmission of ultrasonic energy from the metal insert to the leading end of the polymer pin for fluidizing the leading end.