Rotational control of various pediatric femur fractures stabilized with titanium elastic intramedullary nails

This study investigated the torsional stability of transverse, oblique, spiral, butterfly, and comminuted pediatric femur fractures reduced with titanium elastic nails. Twenty-five fractures were created in synthetic analog pediatric femora (five of each fracture type); each fracture was reduced with two 4-mm-diameter titanium elastic nails. Each reduced femur was tested for rotational stability using an MTS. Angular displacements and torques were recorded, plotted, and regressed, and the slope (torsional stiffness) was determined; analysis of variance was performed between fracture groups and rotational testing direction. The oblique fracture pattern exhibited the greatest torsional stiffness in internal rotation, the spiral fracture pattern the greatest stiffness in external rotation. All reduced fracture patterns possessed a torsional stiffness statistically equal to or greater than the torsional stiffness of the transverse fracture pattern. These results suggest this method of internal fixation provides a consistent means of rotational stability for a variety of fracture patterns in a synthetic model.