Finite Element Analysis Of Anatomical Repair Of AITSI

ObjectiveThrough the finite element analysis of the anterior inferior tibiofibular syndesmosis injuries(AITSI)by means of anatomical repair,the biomechanical stability of AITSI was evaluated,and the scientific basis for the clinical application of anatomical repair of AITSI was provided.MethodsA normal volunteer's ankle CT data was imported into Mimics 20.0 to establish the three-dimensional surface model of the related skeleton.Geomagic Studio 2013 was used to build the geometric solid model.Then the solid model of the screw was established in solid works 2017.The skeleton and the screw were assembled and the three-dimensional solid model of the ankle joint was established.Finally,ANSYS 17.0 was imported to establish the related material properties parameters,set the contact type,and connect the related ligaments.A normal lower tibiofibular syndesmosis model group and five experimental models were established.They were fixed with inferior tibiofibular syndesmosis screw in group B1 and B2,posterior or malleolus fracture(PMF)in group C,inferior tibiofibular syndesmosis screw in group D and anterior tibiofibular ligament(AITFL)in group E.The AITSI model of group B1 was anterior,posterior and interosseous ligament rupture of inferior tibia and fibula,while the AITSI model of group B2,C,D and E was anterior and interosseous ligament rupture of inferior tibia and fibula+PMF.Set the boundary conditions and load the analysis results.The data of different indexes and the differences between the models of each group and the normal group at the neutral position of 600N and different angles of internal and external rotation were observed.ResultsIn this study,the three-dimensional finite element model of foot and ankle was established by using Mimics,Geomagic Studio,solid works and ANSYS software.The structure of the model was accurate and realistic.Compared with other biomechanical experimental literature,the results are similar,which proves the validity of the model.There was no significant difference between B1 and B2 groups in tibial displacement,fibular displacement,maximum stress of talus surface,maximum stress of AITFL at tibial and fibular attachment point and maximum stress of model in two different AITISI models fixed with inferior tibiofibular screw(P>0.05 on both sides),so there was no significant difference between B1 and B2 groups.In comparison with the normal group,there was no significant difference in tibial displacement,AITFL in tibial attachment displacement and maximum stress value of talus between the experimental group and group A.In fibula displacement and AIFL displacement at fibula attachment point,there was significant difference between group B,C,D and E and group A,and the displacement was larger than group A.In terms of the maximum stress value of the model,there were significant statistical differences between group B1,B2 and D and group A,whieh were larger than group A.At the same time,there were statistical differences between group B2 and D and group E,which were larger than group E.In terms of the maximum stress location of the model,group E is almost the same as group A.In group B1,B2 and D,the maximum stress position was in the lower tibiofibular screw.ConclusionFixing the posterior ankle and repairing AITFL is the true anatomical repair of the lower tibiofibular syndesmosis injury,which can effectively reconstruct the biomechanical stability of the lower tibiofibular syndesmosis.