Design of Biomechanical Test Bench for Femoral Nails Using Numerical Simulations and Factorial Analyses

Understanding the mechanics behind the stability of a fracture is of great importance to surgeons, potentially providing them with valuable information to assist in the treatment planning process. By running biomechanical studies, consisting of numerical simulations and experimental testing, several implant configurations and different scenarios can be explored to obtain quantitative results of their performance. However, accurately replicating the mechanical behaviour of a fractured bone is a complex endeavour that requires many compromises and simplifications. Generally, biomechanical studies of the femur simplify its intricate original loading by neglecting the effects of muscle forces and applying a single force to the femoral head, usually representative of a single leg stance.

This work proposes an alternative approach, the design of an advanced test setup that not only takes into account the contribution of the muscles alongside the hip joint force, but that is also capable of replicating multiple different body movement scenarios. The development process of the proposed experimental setup followed a methodology that makes use of musculoskeletal and finite element models combined with statistical analyses, with the goal of assessing the significance of individual muscle and defining multi-load configurations that allow for the realistic reproduction of the physiological loading of the femur in a laboratory setting.