Finite element analysis for effect of different anteromedial cortical reduction on stability of femoral intertrochanteric fractures with intramedullary nail fixation
Objective To explore the effect of different combinations of anteromedial cortical reduction on biomechanical sta-bility of femoral intertrochanteric fractures with proximal femoral nail antirotation(PFNA)fixation using finite element analysis.Methods The CT scan of the femur of a 65-year-old healthy male adult and the PFNA parameters were imported into finite el-ement soft-wares.They were used to create 9 models of femoral intertrochanteric fracture of AO type 31-A2.1 according to each pair of positive,neutral and negative support on the anteroposterior and lateral X-ray films of anteromedial cortex.With the same constraint,axial compression,lateral extrusion and horizontal shear loadings were applied respectively to measure and compare the maximum displacement of the fracture sites,the maximum Von Mises strain on femur and the maximum von Mises stress on implant.Results-The smallest displacement,Von Mises strain and Von Mises strain were observed in the positive-positive group respectively with axial compression,lateral extrusion and horizontal shear loadings.The smallest average dis-placement,average Von Mises strain and average Von Mises strain were observed in positive groups of medial cortical support respectively with 3 loadings,showing significant differences between neutral and negative groups(P＜0.05).Positive groups of anterior cortical support respectively with 3 loadings showed significant differences between neutral and negative groups(P＞0.05).Conclusion The medial cortical support plays a decisive role and the anterior cortical support plays an auxiliary role in the stability of unstable femoral intertrochanteric fractures.Medial cortical negative support is the most risk factor of instability in intramedullary nail fixation.
Femoral intertrochanteric fracturesAnteromedial cortexProximal femoral nail antirotationInternal fixationFi-nite element analysis
NETL
NSTL
万方数据
