Mechanical comparison of reconstruction nail and dynamic condylar screw in the treatment of unstable Subtrochanteric fracture in vitro study

Abstract

Background: Subtrochanteric femur fractures are severe injuries that are often associated with high-energy trauma in young age and a trivial fall in osteoporotic patients. These fractures constitute a major bulk of hip fractures and are difficult to treat. Objective of this study was to determine the rigidity and strength of fixation and ultimate load of failure of certain composite femur models designed to simulate unstable subtrochanteric femur fractures fixed with DCS and Reconstruction nail. Methods: Paired femora were osteotomized to produce like models of an unstable subtrochanteric femur fracture in vitro. The femora were fixed with the Reconstruction nail and a 95 degree dynamic condylar screw plate (DCS). Materials testing machine was used to apply compression to the femoral head through an adapter plate. Stiffness values were calculated from the load-deformation curves obtained. Results: The Reconstruction nail-femur model was stiffer than the 95 degree DCS. The Reconstruction nail also had the highest ultimate load-to-failure than the 95 degree DCS. Conclusion: Our findings suggest that the Reconstruction nail has greater stiffness and strength than the 95 degree dynamic condylar screw when tested in this model of an unstable subtrochanteric femur fracture.