Mechanical Characteristics of the Femoral Intramedullary Nailing Systems Available from Five Different Manufacturers.

Abstract

Abstract : There are few non proprietary papers addressing the mechanical strength of intramedullary nailing devices; none address the characteristics of the proximal and distal ends of these devices. Independent testing of eight femoral intra- medullary nail systems was undertaken at the proximal, middle, and distal regions for rigidity (stiffness) and strength. Each device was a reconstruction nail, 42-46 cm in length. Four or five nails of each size, 10-13 mm diameter, per system were loaded to failure using a four- point bend test. Significant variation was found between systems for strength (yield) and stiffness at the proximal and distal aspects of the rods. A significant difference was observed when comparing the properties of earlier designs with the properties of more recent designs. Mechanical properties did not increase with increasing rod diameter for all systems.