[Establishment of a three-dimensional finite element model and stress analysis of the talus during normal gait].

OBJECTIVE: To develop a three-dimensional (3D) finite element model of the human ankle with fine details and analyze the stress distribution on the talus during different gait phases.

METHODS: Mimics13.0 and Geomagic10.0 software were used for geometric reconstruction of the ankle based on the 3D CT data of the foot. The model was meshed and assigned with the material properties in Hypermesh10.0 software. The model was then imported to Abaqus6.9, and the stress condition of the talus during the 3 phases (heel-strike, midstance, push-off) of normal gait was simulated to calculate the stress distribution within the bone.

RESULTS: The three-dimensional finite element model of the ankle established consisted of 21 865 nodes and 73 440 elements. The stress distribution within the bone in 3 phases of normal gait differed significantly. The peak von Mises stress on the talus dome, from the heel-strike to push-off phases, was 3.0 MPa, 4.3 MPa and 4.8 MPa, as compared to 1.3 MPa, 1.9 MPa and 2.8 MPa on the talar neck, 2.8 MPa, 3.0 MPa, and 3.4 MPa on the talonavicular joint surface, and 2.2 MPa, 1.8 MPa and 1.5 MPa on the subtalar joint, respectively.

CONCLUSION: The finite element model of the talus shows a good response against the experimental data and can be used to simulate the biomechanic experiment of the talus.