The effect of labeling on the fatigue behavior of spinal rods

This study was performed to investigate the effect of laser marking on the fatigue strength of orthopedic spinal rods. Spinal rods from several manufacturers were obtained and tested in a four-point bend configuration. Results indicate that the endurance limit for laser marked rods from the same lot of raw material was on average 33% lower than their non-laser marked counterparts when subjected to the four-point bending test.