Biomechanical analysis of proximal femoral nail antirotation-II and Asia 2 femur nail fixation for femoral subtrochanteric fractures in the elderly / 中国组织工程研究

ABSTRACT

BACKGROUND:Biomechanical studies on elderly subtrochanteric fracture by different fixation ways were more, but study on relatively proximal femoral nail antirotation-II (PFNA) and Asia 2 femur nail (A2FN) fixation for femoral subtrochanteric fractures in the elderly was less. OBJECTIVE:To study the biomechanical analysis of intramedul ary nail PFNA-II and A2FN fixation for elderly femoral subtrochanteric fractures. METHODS:Three-dimensional finite element models of femoral subtrochanteric fractures fixed by PFNA-II and A2FN in the elderly were established. Three-dimensional finite element analysis was used to analyze stress distribution and displacement after femoral subtrochanteric fractures by PFNA-II and A2FN fixation. RESULTS AND CONCLUSION:(1) The overal maximum stress, nail maximum stress and hip screw or spiral blade maximum stress values of PFNA-II intramedul ary fixation system were higher than that of A2FN intramedul ary fixation system. The distal locking maximum stress value and femoral head surface maximum stress values of PFNA-II intramedul ary fixation system were lower than that of A2FN intramedul ary fixation system. (2) The maximum displacement of PFNA-II intramedul ary fixation system was mainly concentrated in the large trochanter and femoral head pole. The maximum displacement of A2FN intramedul ary fixation system was mainly concentrated in the large trochanter. The maximum displacement of PFNA-II intramedul ary fixation system was higher than that of A2FN intramedul ary fixation system. The maximum axial displacement of PFNA-II intramedul ary fixation system was higher than that of A2FN intramedul ary fixation system. The maximum sagittal displacement of PFNA-II intramedul ary fixation system was higher than that of A2FN intramedul ary fixation system. The maximum coronal displacement of PFNA-II intramedul ary fixation system was higher than that of A2FN intramedul ary fixation system. (3) The lateral fissure, front fissure and rear fissure of PFNA-II intramedul ary fixation system were higher than that of A2FN intramedul ary fracture fixation system, but the difference was less pronounced. (4) The maximum stress value on fracture section of PFNA-II intramedul ary fracture fixation system was lower than that of A2FN intramedul ary fixation system. (5) Results showed that A2FN intramedul ary fixation system for intertrochanteric fractures has better biomechanical stability than PFNA-II intramedul ary fixation system for intertrochanteric fractures.