股骨近端抗旋髓内钉螺旋刀片两种锁定方式治疗不稳定股骨粗隆间骨折的力学比较

林臻　　陈少坚　　高连云　　阮康明　　刘清平

[關键词] 股骨粗隆间骨折;PFNA固定;静态锁定;滑动加压;有限元分析

[中图分类号] R687.3          [文献标识码] B          [文章编号] 1673-9701（2021）21-0058-04

Mechanical comparison of two locking methods of the proximal femoral anti-rotation intramedullary nail helical blade in the treatment of unstable femoral intertrochanter fracture

LIN Zhen   CHEN Shaojian   GAO Lianyun   RUAN Kangming   LIU Qingping

Department of Orthopaedic Trauma，Mindong Hospital Affiliated to Fujian Medical University，Ningde   355000，China

[Abstract] Objective To compare the biomechanical properties of the proximal femoral anti-rotation intramedullary nail helical blade static locking and sliding compression fixation in the treatment of unstable femoral intertrochanter fracture，and to provide a scientific basis for the selection of internal fixation in clinical surgery. Methods The finite element model of the femur was established based on the three-dimensional original CT images of healthy adult males. The internal fixation model was established using Solidworks software. Twenty finite element models of unstable （Evans-Jensen Ⅳ/Ⅴ） femoral intertrochanter fracture internal fixation with different fracture line positions and degrees of displacement were simulated. Two models of the helical blade （static locking and sliding compression） were imported into Abaqus analysis software， and the femoral stress when the single foot was standing was simulated. The same constraint and load were applied. The force distribution and displacement magnitude were observed. Results It was seen from the finite element model diagram that the stress was mainly distributed in the femoral neck，large and small trochanter， middle and lower segment，and the stress at the small site was relatively concentrated. In the two states of standing and walking，the stress and displacement of the helical blade static locking fixation in the PFNA internal fixation model of two different types（type Ⅳ/Ⅴ） of femoral intertrochanter fractures were lower than those of sliding compression fixation，and the differences were statistically significant （P<0.05）. Conclusion Compared with sliding compression locking， helical blade static locking has less mechanical stress and more reasonable distribution in the treatment of unstable femoral fracture with femoral antirotation intramedullary nail，which has better biomechanical advantages for fracture healing.