| Purpose:With the release of the "Healthy China 2030" plan by the Central Committee of the Communist Party of China and the State Council,the construction of a healthy China has been vigorously promoted.Exercise has become an important part of the people’s daily life.With the increase in exercise,people have higher requirements for the functional integrity of the ankle and foot,and the proportion of ankle injuries are also increasing year by year.In the past studies,the research on the bifurcate ligament mainly focused on the anatomical and morphological research,and there were few studies on the biomechanics of the bifurcate ligament.In this study,by establishing a three-dimensional model of the foot and ankle joint complex and using finite element analysis to analyze the mechanical changes of the calcaneocuboid joint,the talonavicular joint and the bifurcate ligament after the bifurcate ligament injury,it provides more theoretical basis for the biomechanics of the bifurcate ligament for the biomechanics of bifurcate ligament.Methods:1、The right ankle of a 25 years old adult male volunteer was scanned to obtain image data through computer tomography.Through Mimics Medical 21.0 software,the image data in DICOM format is extracted,and the two-dimensional image is converted into a three-dimensional model using Mimics Medical 21.0 software,and finally the tibia,fibula,talus,calcaneus,cuboid,navicular,cuneiform,metatarsal,phalanx and the soft tissue.The model is saved as a Stl format through the Mimics Medical software.2、Import all the bones into the Geomagic Wrap software in turn to smooth each bone and construct the surface,and finally save it with the STP format file.The processed models were imported into Solidworks 2017 software for assembly,and the articular cartilage,rigid ground and the sketches of the linear ligament were constructed in the Solidworks 2017 software.The generated bone and soft tissue models were saved in XT file format.3、Import the XT file into Workbench 17.0 to assign the material properties of the model,establish Link10 line body ligament and spring ligament,complete the mesh division of the model,set the boundary conditions and loads,and check the validity and reliability of the model with reference to the previous literature.4、The calcaneocuboid ligament and calcaneavicular ligament were removed from the foot and ankle joint complex model to simulate the damage of the bifurcate ligament.The models were subjected to loads in normal neutral position,inversion,adduction,and plantar flexion respectively.Finite element analysis was carried out on four groups of stress models with the calcaneonavicular ligament injury,the calcaneocuboid ligament injury,and calcaneonavicular ligament injury combined calcaneocuboid ligament with injury.Results:The complete foot and ankle joint complex are consists of 1,121,390 nodes and 664,871 elements.The final model including the tibia,fibula,talus,calcaneus,cuboid,navicular,cuneiform,metatarsal,phalanx,soft tissue,ligaments,and articular cartilage.By comparing the articular surface of the distal tibia and the stress distribution and the plantar equivalent pressure with the analysis results of the related ankle finite element analysis,it is proved that the model has good simulation performance and can be used for finite element analysis.The bifurcate ligament injury model was simulated by finite element software.After the bifurcated ligament was injured,the dorsal calcaneal ligament would receive a correspondingly greater equivalent stress,which was most obvious in the plantar flexion position.When the calcaneocuboid ligament is injured,the maximal stress of the talonavicular articular surface under normal load is significantly increased.After the bifurcate ligament injury,the mechanical distribution of the midfoot will change to varying degrees due to the injury,which may further lead to instability of the transverse tarsal joint of the foot.Conclusion:Through the three-dimensional finite element software,the modeling of the three-dimensional finite element model of the normal ankle and joint are completed,and the three-dimensional finite element model is compared with the previously established ankle and joint model,which verifies the validity of the finite element model in this experiment.The finite element analysis of the bifurcate ligament injury was carried out through this model,and it was found that the bifurcate ligament would affect the mechanical stability of the midfoot to varying degrees,which provided a new method for the biomechanical study of the bifurcate ligament. |
