| Plates have been widely used in internal fixation for femur fracture healing in clinical. The main problem of current clinical work is how to choose a reasonable fixation style, increase the effect to promote fracture healing, reduce the negative effects to bone and ensure the internal fixation in effect.We investigated the effects of each constituent issue in internal fixation system with numerical simulation, which can provide reference for solving the clinical problem of internal fixation system. For example bone plate, screws, intact bone and broken bone.Using three-dimensional finite element method, we analyzed the internal fixation system of femur cross-broken. First, three kinds of bone fracture plate were selected and different screw missing fixation styles were considered, the effects on the femoral fracture system were analyzed. Second, the most optimal fixation style of NiTi alloy, Ti-6Al-4V and Ti plates and corresponding plate fixation were gotten by the analysis and the influence of plate material type to fracture system were also studied. The third, the effects of these three plates to the broken femur recovery were also presented.The simulations show that the length and screw missing fixation styles both influence the stability of fixation system, the stress shielding degree of femur and the stimulative effect to broken femur recovery. The optimal plate length is five to six times the diameter of the broken bone and the best internal fixation is the fixation without screw missing. NiTi alloy is a more suitable material to be used for bone plate, it not only can reduce the stress shielding effect but also can provide effective deformation stimulation to the bone. These issues benefit to the recovery of broken bone. With the increasement of material elastic modulus, the speed of fracture recovery decreases. The broken femur with bone fracture plate of NiTi alloy has the fastest recovery rate of three internal fixation systems. This study is more important for clinical to select internal fixation styles and to design the new type plate. |
