Device for fixation of bone fractures

摘要

A device and method for fixation of bone fractures has a bone screw comprising a shank with a threaded end portion, on the outer surface. The screw has a through bore with two bore portions differing in diameter. A step in the diameter is formed between these bore portions and is located within the end of the screw having the thread. This step in diameter can support a metal insert which in turn supports a polymer pin when the latter if pressurized with a sonotrode in the bone screw. Together with an applied ultrasonic vibration the pressure fluidizes the polymer pin and presses the material through holes configured in the wall of the bone screw and into surrounding bone.

主权项

1. A method for fixation of a bone fracture comprising:
inserting a bone fastener having a bore therein and a plurality of ports for communicating between the bore and a bone across a fracture site, the bore of the bone fastener having an annular step formed therein; mounting a metal insert on a leading end of a polymer pin; inserting the polymer pin having the metal insert into the bore of the bone fastener and sliding the combination along the bore of the bone fastener until the annular step is contacted, wherein the leading end of the polymer pin contacts the metal insert and wherein the annular step contacts the metal insert, the annular step formed adjacent to the ports in the bone fastener; ultrasonically melting the polymer pin; and forcing melted polymer of the polymer pin through the ports in the bone fastener and into the bone.