Research On Simulation Of Bone Remodeling

Simulation of bone remodeling is a multi-discilinary research subject, which involves solid mechanics, FEA and orthopaedic knowledge. It plays an important role in medical diagnosis, designing and manufacturing internal implants, surgical planning, treatment of bone diseases and so on. As a result, research on bone remodeling is of great academic and technical value.This paper focuses on three main points. The first one is about preprocessing of 3-D FEM of human bones, which includes establishing and meshing FEMs based on CT images; The second one is remodeling criteria in numerical simulation; Finally, the developed remodeling criteria is implemented on diverse human bones such as femur on gait, cranio-maxillofacial bone, and bone remodeling effect after fracture and inclusion of an artificial element and so on.Acturally, bone remodeling is a sort of complicated biological activity, which represents nonlinear characteristics not only on the materials but also on boundary conditions, because it is a coupled result of biological functions and external stresses. In this algorithm, the new densities and elastic moduli are calculated from initial bone densities by using certain simulation criterias, and the new-born densities are taken into consideration in the next step of Euler-forward iterative calculation. The process is proved to be an overall converging behvior of the numerical solution, bone remodeling is simulated from 300 to 3000 days based on different FEMs, it comes to good performance by comparing these results with CT images and other experiments.In this paper, CT images are extracted and converted into 3-D FEMs by using method of reverse engineering, and the FEMs are meshed and preprocessed reasonably. In all, A 2-D femur model is calculated for bone remodeling of 3000 days, the results are creditable in good consistence with clinical obervations; A 3-D cranio-maxillofacial bone is computed for bone remodeling of 300 days, certain sections of simulated model represent similar with CT images; A 3-D femur model (with muscle forces) on gait situation is calculated for bone remodeling of 300 days, it demonstrates that results coincide with real femur in some areas by comparing the diaphysis zone; Simulating a model of an intact proximal femur and a total hip replacement, It is possible to reproduce the slight enlargement of the cortical layer at the distal extremity of the prosthesis.It is a significant research direction of bone modeling simulation that developing an reliable anisotropic criteria for more complex bone structures.