Finite Element Analysis Of Mechanical Changes Of Ankle Joint After Peroneal Osteotomy In Different Positions

Objective:To investigate the mechanical changes of different height perfibular osteotomy and its influence on ankle joint,and to provide theoretical guidance for the selection of appropriate perfibular osteotomy location for the repair of mandible defect.Methods:The left lower limb CT imaging data of 10 patients from the CT Room of the First Affiliated Hospital of Bengbu Medical College from June 2020 to June 2022 were included,including 7 males and 3 females,aged 20-60 years with a median age of 43 years,4 patients with oral cancer and 6 patients with fracture of the right lower limb.Based on the original CT scan data of the patient,a three-dimensional finite element model containing the tibia and fibula and ankle joint was constructed using Mimics,Geomagic,Solidworks,Abaqus and other software.They were divided into 5 groups according to different height of fibula osteotomy: Group A was the bone model containing the complete tibia-fibula and ankle;group B to E were the bone models of tibia-fibula and ankle with the 8 cm long fibula intercepted upward at 5 cm,7cm,9 cm and 11 cm from the lower end of the fibula,respectively.Constraints and loading conditions were set for the models to obtain the stress distribution and changes.With group A as the control group and B,C,D and E as the observation group,statistical methods such as analysis of variance and SNK-q test were used to compare and analyze the stress changes in the surface of the tibiotalar articularis,talofibular articularis,calcantalar articularis and tibiofibular articularis of each model.P < 0.05 was considered as statistically significant.At the same time,the change of tibial force line was observed and analyzed.Results:Compared with the control group,the stress changes of each joint surface in the observation group were statistically significant(all P < 0.05).The stress at the tibial talus joint surface and calcaneal talus joint surface increased after fibula osteotomy.In group B,the stress reached the maximum when the distal fibula was preserved for 5cm.The stress of talofibular articular surface and tibiofibular articular surface decreased after fibula osteotomy.In group B,the stress was minimum when the distal fibula was preserved for 5cm.The changes were most significant when the distal fibula was least preserved(5cm).The stress on the tibiofibular articular surface and talofibular articular surface decreased significantly due to structural changes after osteotomy,while the stress on the medial tibia increased significantly,and the stress on the tibiotalobular articular surface shifted inward.Conclusion:The lower the peroneal osteotomy is,the greater the variation of the stress of ankle joint surface is.Therefore,in clinical operations such as upward fibula transplantation to repair mandibular defects,keeping more distal fibula as much as possible can minimize the impact of fibula osteotomy on ankle joint function under the premise of guaranteeing the repair effect.