摘要
目的对3枚空心钉"轴心加压+侧方支撑"新构型固定股骨颈骨折的生物力学特性进行三维有限元分析,为临床应用提供理论依据。方法选取1名健康成年男性志愿者,采用股骨CT扫描数据建立三维模型后模拟PauwelsⅡ型股骨颈骨折,分别采用正三角形、倒三角形、"轴心加压+侧方支撑"构型空心钉进行固定,在不同负荷下对空心钉应力分布及峰值、股骨位移分布及峰值、股骨颈骨折头侧端应力分布及峰值进行分析。结果各组上方空心钉应力大于下方空心钉,应力大多集中于螺纹与螺杆交界处并向两端呈减小趋势,螺钉尾部应力局部又有所增大。各组股骨位移最大处为股骨头负重处,从上向下位移递减。正三角形组股骨颈骨折头侧端应力高度集中,位于下方偏前处,而倒三角形组与新构型组断端应力相对较均匀分散于股骨颈下半部分。1倍体重负荷下正三角形组空心钉应力峰值(150 MPa)、股骨位移峰值(0.69 mm)、股骨颈骨折头侧端应力峰值(51 MPa)最高,倒三角形组次之(分别为93 MPa、0.65 mm、22 MPa),新构型组最小(分别为77 MPa、0.58 mm、18 MPa)。随着负荷增加,各组空心钉应力峰值、股骨位移峰值、股骨颈骨折头侧端应力峰值相应增加,但新构型组始终最小。结论 "轴心加压+侧方支撑"新构型固定的空心钉较三角形排列的空心钉承受应力和位移较小,且骨折端应力较小,整体稳定性较好。
ObjectiveTo investigate the biomechanical characteristics of three cannulated screws in new configuration of‘axial compression and lateral buttress’ in the treatment of femoral neck fractures by three-dimensional finite element analysis, so as to provide the basis for clinical application.MethodsA healthy adult male volunteer was selected in the study. The femur was scanned by CT. After establishing a three-dimensional model, the Pauwels type Ⅱ femoral neck fracture was simulated.The fractures were fixed by screws in three configurations of regular triangle, inverted triangle and‘axial compression and lateral buttress’, respectively. Under different stress conditions, different parameters were measured including the stress value of cannulated screws, the displacement of femur and the stress distribution of the fracture end.ResultsThe stress value of the upper cannulated screws was greater than that of the lower cannulated screws in each group. The stress was mostly concentrated at the junction of thread and screw, decreased to both ends, and increased at the tail of screws. The displacement of femur in each group decreased from top to bottom, and the largest one was located at the weight-bearing position of femoral head. In the regular triangle group, the stress at the fracture end of the femoral neck was highly concentrated, located inferior and anterior while the stress at the fracture end in the inverted triangle group and the new configuration group was relatively dispersed in the lower half of the femoral neck. Under the load of normal body weight, all mechanical parameters were the highest in the regular group, including the peak stress of cannulated screws(150 MPa), the peak displacement of femur(0.69 mm) and the peak stress at the head end of femoral neck fracture(51 MPa). These parameters were the second in the inverted triangle group(93 MPa,0.65 mm and 22 MPa respectively) and the smallest in the new configuration group(77 MPa, 0.58 mm and 18 MPa respectively).With the increase of load, the above mechanical parameters increased correspondingly in each group. However, they were always the smallest in the new configuration group.ConclusionConsidering that the stress of cannulated screws and displacement of femur in the new configuration are smaller than that of the triangular configurations, the overall biomechanics stability of new configuration is better.
作者
钟志辉
林焱斌
庄研
叶友友
许阳凯
ZHONG Zhi-hui;LIN Yan-bin;ZHUANG Yan;YE You-you;XU Yang-kai(Department of Orthopaedics,Fuzhou Second Hospital Affiliated to Xiamen University,Fuzhou,Fujian 350007,China)
出处
《中国骨与关节损伤杂志》
2021年第10期1023-1026,共4页
Chinese Journal of Bone and Joint Injury
基金
福州市卫生健康科技创新平台建设项目(2019-S-wp2)。
