The Influence Of Total Knee Replacement On Proximal Tibia Bone Remodeling

Total knee replacement surgery is one of the most effective treatments to reducearthritis patients’ pain. However, aseptic loosening and sinking of prosthesis is aserious problem affecting the duration of total knee replacements currently. Decreaseof bone mineral density caused by stress shielding effect of prosthesis is one of theimportant reasons to induce the postoperative symptoms. Bone remodelingsimulations can be used to predict tibial bone density and changes of bone mineraldensity after total knee arthroplasty. It’s of great significance to explore the clinicalfailure mechanisms of prosthesis and prevent the occurrence of adverse symptoms.The content of this dissertation mainly included: firstly, to model the proximaltibia and prosthesis. Then to divide the model into tetrahedral elements by smart gridpartition method after importing the model into ANSYS software. The program offinite element calculation was compiled by the APDL language of ANSYS, and theprogram of bone remodeling was compiled in MATLAB. Simulation of proximal tibiaremodeling process was achieved by MATLAB calling ANSYS program. Fourtibia-prosthesis finite element models were established to simulate tibia boneremodeling after total knee replacement. These four prosthetic models had the sameshape but with different materials, which included two functional gradient materials,the titanium alloy and an ideal bone material. The influences of different materials ofprosthesis on tibia bone remodeling were analyzed.The results showed that, in comparison with the model using titanium alloyprosthesis, the stress shielding effect was reduced to a certain extent for the modelsusing two functional gradient prosthesis since the tibia assumed higher Von Misesstress. At the same time, in the models using functional gradient materials, theinterface shear stress between tibia and prosthesis distributed more evenly, so thestress between tibia and prosthesis can be transferred more effectively. However, thesimulation result of bone density distribution showed that the discrepancies between these four materials prosthesis were not obvious. The effects of short shank kneeprosthesis on bone remodeling were very limited. This dissertation provides certaintheoretical basis for the improvement of material and structure of knee prosthesis. It’salso served as a basis to deeply investigate the interaction between knee prosthesisand bone.