Different fixations for intertrochanteric fracture affect proximal femur stress:a finite element analysis / 中国组织工程研究

ABSTRACT

BACKGROUND:The mechanical characteristics of intramedul ary and intramedul ary fixations for treating intertrochanteric fracture were hot research of finite element, but there was few comparative research on tension side and pressure side of proximal femur. In our study, we found that the distribution of the stress zone was important indication to researches on intertrochanteric fracture and internal fixation design. OBJECTIVE:To explore the effects of intramedul ary and extramedul ary fixations for treating intertrochanteric fracture on pressure side and tensile side of proximal femur. METHODS:CT scan and Mimics modeling of volunteer’s femur were conducted, and the model Evans type I intertrochanteric fracture was constructed and treated with proximal femoral nail antirotation and dynamic hip screw respectively. The stress condition of proximal femur in weight status was simulated. The Abaqus 6.13 was used for finite element analysis, and the tension side and pressure side of proximal femur in both fixations were also analyzed. RESULTS AND CONCLUSION:(1) The stresses of compressive side and tensile side in proximal femoral nail antirotation group were both less than that in dynamic hip screw group. The stress of proximal femur in proximal femoral nail antirotation group was more similar to that in physiological status. (2) These findings verified that for treating intertrochanteric fracture, intramedul ary fixation exerted better mechanical behavior than extramedul ary fixation. The protection of compressive side and tensile side of proximal femur had achieved by intramedul ary fixation.