Finite Element Analysis Of Osteoporosis

With more and more serious aging problem over the world, the proportionof osteoporotic patients is increasing. Osteoporosis has become a serious healthproblem and obtained wide public attention. Osteoporosis is the most commonmetabolic bone disorder, affecting one in four women and one in eight men olderthan50years. It is a systemic skeletal disease that characterized by bone masslose and bone microstructure degradation that predisposes to fracture. Recentstudies shown that osteoporotic bone had significantly increased marrow fatcompare to the subjects with normal bone mineral density. However, there wasno study to further investigate the mechanical function of the marrow fat in theosteoporotic bone.Finite element method has been used in biomechanical area for long. F initeelement method has been applied into biomechanical research for vertebra,femur and bone turnover and provided a lot research finding. Finite elementmethod is mainly based on reconstruction of medical image data, and forms a3Dbone structure, by which we can operate virtual biomechanical experiments.Biomechanical experiment in reality can also get bone mechanical parameters,however, irreparable damage will be create on bone which impact verifiabilityand predictability. This article used finite element method to studybiomechanical properties of cancellous bone with and without bone marrow.Based on finite element analysis, this thesis established a3D modelcoupling trabecular bone and bone marrow together. The mechanicalinteraction between trabecular bone and bone marrow was studied through thismodel. On one hand, in the region of interest marrow cavity was replaced byyellow marrow. Further, this study analyzed the properties of trabecular boneand yellow marrow material and set different loading types on the model. Through simulation in finite element software,3D stress map was obtainedwhich contain trabecular bone and yellow marrow. On the other hand, the sameprocess was conductedon cancellous bone with red marrow which was set asfluid. By establishing fluid-structure interaction equation, we conducted finiteelement method on trabecular bone and red marrow model. It was found thatthe maximum stress was different in trabecular bone and different marrow. Inthis study, we found that the bone strength of cancellous bone and yellowmarrow coupling model reached maximum among three models. The resultsshowed that the increases of yellow marrow can significantly improve bonestrength.