Three-dimensional Reconstruction And Finite Element Analysis Of The Femur And Prosthesis In Total Hip Joint Replacement

More serious inconveniences to patients caused by the diseases of hipjoint are brought by accident and lesions in our daily life; hiparthroplasty can cure hip diseases. In total hip replacement, stabilityand service life of the artificial hip joint are the key to the surgery.It not only depends on the doctor’s surgical technique, but also has aclose relationship with the fixation of artificial hip. Nowadays, thereare many types of artificial hip. According to the fixation, they can bedivided into biological femoral stem and cemented femoral stem. In totalhip joint replacement, both types of femoral stems have been widely used，but which one can provide better stability and longer service life hasnot been identified yet. In this dissertation, we discuss the stabilityand service life of the above two femoral stems using finite element method.Mimics, Abaqus and Catia softwares enable the three-dimensionalreconstruction of the femur model and establishment of the prosthesismodels. Femur material properties are given through gray value of femurCT images using Mimics software, thus we can establish a finite elementmodel of the femur with high precision. Prosthetic models are establishedaccording to their specific sizes using Catia software. We analyzed thecomplete femur model, the proximal femur model, the femur model with thebiological femoral stem and that with the cemented femoral stem. It wasfound that the stress concentration position of the proximal femur wasat the bottom of the femoral neck, and that of the femoral shaft was atthe bottom1/3of femoral shaft. For the complete femur model, the finiteelement analysis results were influenced by the gluteus medius muscleforce and gluteus minimus muscle force, and other muscle forces had littleinfluence. The hip joint contact forces with the same value and positionbut different action areas have effects on stress distribution of the loading position that on the femoral head, but they have no effect onstress distribution of other positions. For femur model with the femoralstem, the stress in the biological femoral stem is transferred to the femurthough, it can improve the ability of resistance to fatigue failure offemoral stem and promote growth of bone. But the better stability was foundin the cemented femoral stem.