关键词: 踝关节, 数字模型, 有限元分析, 生物力学, 数字化影像医学

Abstract:

BACKGROUND: In recent years, the finite element analysis has been widely used in the field of biomechanics.
OBJECTIVE: To perform biomechanical analysis of the ankle three-dimensional digital model through ANSYS, a large-scale software of finite element analysis, and to investigate the regularity of stress distribution and the deformation and displacement of the ankle model.
METHODS: The three-dimensional digital model of ankle that processed by MIMICS, Geomagic and ANSYS was imputed into the ANSYS, then made a finite analysis of the obtained model after constraining conditions, loading pressure and solving.
RESULTS AND CONCLUSION: ①Under the condition of standing, the maximum stress distribution of the ankle joint was mainly in the medial malleolus and talus junction, the anterior part of the intercondylar line of distal tibial articular surface, the leading edge of the cortex area in the middle and lower segments of the tibia and the lateral part of the trochlea of talus; the minimum stress was mainly distributed on the lateral malleolus, the medial cortical area of the distal tibia and head of talus and neck of talus; the maximum displacement was mainly occurred on the head of talus and gradually decreased from up to down; the minimum displacement was on the tibia and the 1/3 of the middle and lower segments of fibula. ②Under the condition of falling, the maximum stress distribution of the ankle joint was mainly in the leading edge of the cortex area in the middle and lower segments of the tibia, the lateral part of the trochlea of talus, the medial malleolus medial cortex and the anterior part of the intercondylar line of distal tibial articular surface. With the pressure increased in the middle and lower segments of the tibia, the stress concentration area would move to the medial slightly. The position of the maximum stress concentration area of the lateral part of talus trochlea was not changed significantly, and the area was gradually increased. The minimum stress was mainly in the lateral malleolus, the lateral part of the distal tibial articular surface, and head of talus and the lateral cortex of the medial malleolus; with the pressure increased, the small stress blue area of the medial malleolus lateral cortex was gradually decreased. The blue region with larger stress was appeared in the lateral malleolus which suggest the increasing of the stress. The maximum displacement was appeared from the head of talus and upper to the neck of talus and tibiotalar articular surface and gradually diminished in the middle and lower segments of the tibiofibula.