Three-dimensional modeling and analysis of a human ankle joint

Developing an accurate finite element model of an ankle joint is a challenging task and time consuming. Several steps were utilized to minimize over-simplification of the model as can be found in literature. The objective of this study is to biomechanically analyzed, via the finite element method, a more precise model of a human ankle joint. Computed Tomography dataset of a healthy male volunteer was used to reconstruct a detailed three-dimensional model of an ankle joint. The bone models were segmented into two types of bones - cortical and cancellous according to the Hounsfield unit. The ankle model consists of tibia, fibula, talus, calcaneus, cuboid, navicular, three cuneiforms and five metatarsals bones. The cartilages were constructed by offsetting bone layer and were assigned with the Mooney-Rivlin mechanical behavior. To complete the joint, thirty-seven ligaments were modeled using linear spring elements. Finite element method was used to analyze the effect of seven different forces applied on the tibia. Displacements of the model were compared with previous experimental work. The results showed that the predicted displacement of the medial cuneiform bone was similar to those experimental work reported by others.