COMPARISON OF THE MECHANICAL PERFORMANCE OF TROCHANTERIC FIXATION DEVICES

The transtrochanteric surgical approach to the hip is commonly used, e specially for revision hip surgery. Failure of the trochanter to heal can lead to hardware failure, persistent pain, and limp. Rigid interna l fixation is needed in this approach to achieve an adequate rate of h ealing. Newer cable and cable grip systems have been designed to impro ve trochanteric fixation, but have not been compared to the older Char nley wire fixation techniques. In this study, an in vitro mechanical m ethod previously used to test wire fixation methods was used to compar e wire, cable, and cable grip fixation methods. A quasistatic mechanic al distraction device was used to compare structural stiffness, load t o clinical failure, energy to clinical failure, and maximum load resis ted by the fixation devices. The cable grip system was found to be sti ffer, to resist a larger load to mechanical failure at l-cm displaceme nt, and to absorb a greater amount of energy to clinical failure when compared with the other systems. These data suggest that use of the ca ble grip fixation method should result in improved clinical success co mpared with the Charnley wire technique.