Biomechanical comparison of flexible intramedullary nailing versus crossed Kirschner wire fixation in a canine model of pediatric forearm fractures.

This study compares the biomechanical properties of crossed Kirschner wires with those of flexible intramedullary nails in a canine model. The Kirschner wire groups had greater anteroposterior, lateral, and torsional stiffness and force to failure rates in most of the bones tested. Bones fixated with flexible intramedullary nails could bend and recoil during failure testing. The bones fixated with Kirschner wires failed at smaller levels of displacement and frequently had hardware cut-out during failure testing. Flexible intramedullary nails have more recoil and do not induce new fracture lines, which may explain their clinical superiority to Kirschner wires despite providing less rigid fixation.