Biomechanical effect of adult posterior malleolus fracture on ankle joint based on three-dimensional finite element model
Objective To investigate the biomechanical effects of adult posterior malleolus fractures on ankle joint using three-dimensional finite element model analysis.Methods According to the CT data of ankle joint from one healthy adult male,the solid model of ankle was constructed and imported into Ansys 10.0 finite element analysis software,then three-di-mensional finite element model of ankle was established,the validity of the model was verified.The load and conditions of an-kle in standing condition were set,the tibia joint cartilage contact area,maximum Mises stress,maximum contact stress and mean contact stress and other parameters in state of 1/5,1/4,1/3,1/2 range of posterior malleolar fracture were compared.The contact stress peak values of tibiotalar joint in different states were compared by simulating the states of fibula external dis-placement,shortening,internal rotation and external rotation.Results With the fracture range increased,the contact area of tibia cartilage decreased,and the maximum Mises stress,the maximum contact stress and mean contact stress of tibial cartilage increased.At fracture range was more than 1/3,the contact area of tibiotalar joint was significantly reduced and joint displace-ment was significantly increased.The differences of the maximum contact stress peak values of tibiotalar joint caused by exter-nal rotation,internal rotation,external displacement and shortening of fibula were 17.6％,17.7％,45.3％and 10.3％,re-spectively.Conclusion It is demonstrated that high simulation of ankle model can be established using three-dimensional finite element technique,and posterior malleolus fracture range exceeds 1/3 will affect contact state of tibiotalar joint.With fracture range increases,the contact area of the joint decreases,the contact stress increases and the relative displacement trend of the joint increases,which will cause degeneration of tibiotalar articular cartilage.Meanwhile,different fibula displacement state will affect tibiotalar articular surface contact state.The study provides an important theoretical basis for diagnosis of traumatic arthritis and joint reset of posterior malleolar fracture.
NETL
NSTL
万方数据
维普
