Finite Element Analysis Of Intertrochanteric Fracture Fixed With PFNA And InterTan

Objective:To compare the biomechanical stability of AO3 intertrochanteric fracture fixed with proximal femoral nail- antirotation(PFNA) and Inter Tan by finite element analysis(FEA),and to provide theoretical basis for clinical application.Methods:Three 3D finite element models of the AO3.1,AO3.2,AO3.3 intertrochanteric fracture with two ways of fixations were established.The comparison was completed of the different fixations for von Mises distribution,and the von Mises distribution of the the femur and the maximum pressure on different points of femur and nail respectively.Results:The FEA indicated that the maximum pressure concentration area in AO3.1 intertrochanteric fracture with PFNA was located in the lateral proximal femur,and with Intertan was located in the medial proximal femur.The AO3.2 had little differences between two types of nails.The AO3.3 intertrochanteric fracture with PFNA was located in the medial proximal femur and the midial distal implant,and there was no significant pressure concentration with Inter Tan.The von Mises pressure of 6 models were concentrated in the medial distal implant,higher maximum von Mises pressure was found in the PFNA.There was significant difference of von Mises distribution between the lateral and medial implant with PFNA. Except the AO3.3 intertrochanteric fracture with PFNA,the maximum pressures of remaining models were located main nail and interlocking nail infall.Conclusions:The fracture fixed with Inter Tan exhibited fine fixation stability in the AO3.1 and AO3.3 intertrochanteric fracture.There was no significant difference of fixation stability between PFNA and Inter Tan in AO3.2.The von Mises distribution of Inter Tan for intertrochanteric fracture is more reasonable.