Finite Element Analysis on Tibia with Osteogenesis Imperfecta: The Influence of Incomplete Bone in Model Reconstruction

Abstract

Osteogenesis Imperfecta (OI) patients continuously experience bone fractures throughout their lifetime. To date, physicians still have difficulties to determine a suitable method to predict fractures. The paper aims to develop finite element (FE) model based on patient-specific computed tomography (CT) images for the purpose of determination of fracture risk. Three types of FE models have been developed using VOXELCON. The first tibia model was a complete tibia composed of epiphysis and diaphysis part of the bone. The second tibia model only include the diaphysis part of the bone which is the shaft. The final tibia model, composed of diaphysis, and a part of epiphysis of the bone which is the extension shaft. Each model uses the same Young's Modulus (19 GPa) and Poisson's ratio (0.3). The developed models were used for FE analysis using VOXELCON under various loadings, and then the results of the different models were compared. Geometry and volume of the models, and surface area of load applied on the models affect distribution of von Mises stress. All the stress values were judged by the fracture criteria, assumed at 115 MPa. It was found out patient is safe in the standing position. Conversely, jumping will cause fracture in the three types of FE models.