Cyclic Cantilever Fatigue Testing of Compression Hip Screw Plates
SourceIn order to evaluate the fatigue strength and fracture mode of various compression hip screw plates, five different hip screw plate designs manufactured by four different companies were evaluated by cantilever loading the lag screw in the horizontal position with a predetermined load until failure. The plate portion of the device was secured to force the fracture to occur in the lag screw, barrel, or barrel/plate junction. The different products exhibited three different fracture modes and displayed as much as a 25X difference in the fatigue life averages. Design, material and processing differences were cited for this wide range of fatigue performance. The load which was used was extremely severe and was designed to determine a finite life for each design under specific test conditions. This information could be used for comparison purposes and for standardizing future testing.