中国组织工程研究 ›› 2021, Vol. 25 ›› Issue (24): 3855-3859.doi: 10.12307/2021.092

• 骨科植入物 orthopedic implant • 上一篇    下一篇

可吸收螺钉联合爱昔邦缝线固定长螺旋投弹骨折的有限元分析

覃万安,蔡洲瑜,韦葛堇,林舟丹   

  1. 中国人民解放军联勤保障部队第九二三医院骨科,广西壮族自治区南宁市   530021
  • 收稿日期:2020-07-03 修回日期:2020-07-07 接受日期:2020-10-16 出版日期:2021-08-28 发布日期:2021-03-08
  • 通讯作者: 林舟丹,硕士,中国人民解放军联勤保障部队第九二三医院骨科,广西壮族自治区南宁市 530021
  • 作者简介:覃万安,男,1980年生,壮族,广西壮族自治区南宁市人,2012年广西医科大学毕业,硕士。
  • 基金资助:
    广西自筹经费科研课题(Z20190963),负责人:林舟丹

Finite element analysis of absorbable screws and ethibond sutures for the treatment of humerus shaft fractures caused by grenade throwing

Qin Wan’an, Cai Zhouyu, Wei Gejin, Lin Zhoudan   

  1. Department of Orthopedics, 923 Hospital of Chinese People’s Liberation Army Joint Logistic Support Force, Nanning 530021, Guangxi Zhuang Autonomous Region, China
  • Received:2020-07-03 Revised:2020-07-07 Accepted:2020-10-16 Online:2021-08-28 Published:2021-03-08
  • Contact: Lin Zhoudan, Master, Department of Orthopedics, 923 Hospital of Chinese People’s Liberation Army Joint Logistic Support Force, Nanning 530021, Guangxi Zhuang Autonomous Region, China
  • About author:Qin Wan’an, Master, Department of Orthopedics, 923 Hospital of Chinese People’s Liberation Army Joint Logistic Support Force, Nanning 530021, Guangxi Zhuang Autonomous Region, China
  • Supported by:
    the Self-Funded Research Project of Guangxi Zhuang Autonomous Region, No. Z20190963 (to LZD) 

摘要:

文题释义:
可吸收螺钉:一类用聚左乳酸等可在体内降解的材料作为原料制备的骨科手术螺纹钉。骨折愈合前,螺钉在体内可起到支撑固定的作用。经过半年到1年的时间后,螺钉又可被人体降解吸收,常用于松质骨骨折尤其是关节内骨折固定。
有限元分析:利用数学近似的方法对真实物理系统(几何和载荷工况)进行模拟。利用简单而又相互作用的元素(即单元),就可以用有限数量的未知量去逼近无限未知量的真实系统。有限元分析是用较简单的问题代替复杂问题后再求解,它将求解域看成是由许多称为有限元的小的互连子域组成,对每一单元假定一个合适的(较简单的)近似解,然后推导求解这个域总的满足条件(如结构的平衡条件),从而得到问题的解。因为实际问题被较简单的问题所代替,所以此解不是准确解,而是近似解。

背景:目前治疗长螺旋投弹骨折的方法有很多,如悬垂石膏固定的保守治疗方法,以及使用锁定钢板、螺钉、髓内钉等内植物的手术治疗方法,但使用可吸收螺钉联合爱昔邦缝线内固定进行治疗为此课题组首次报道。
目的:应用有限元分析方法,评价可吸收螺钉联合爱昔邦缝线固定长螺旋投弹骨折的骨折稳定性,为临床应用提供参考。
方法:收集中国人民解放军联勤保障部队923医院骨科1例志愿者的肱骨CT数据,分别建立钢板(钢板组)、可吸收螺钉(螺钉组)、可吸收螺钉联合爱昔邦缝线(联合组)固定长螺旋投弹骨折的有限元模型,设置3种工况:①固定肱骨头,向肱骨远端施加300 N纵向压缩载荷;②固定肱骨头和肱骨远端,向肱骨中段施加350 N弯曲载荷;③固定肱骨头,向肱骨远端施加15 N•m旋转载荷。评价3种工况下各组模型骨折面最大位移、骨折面平均等效应力与可吸收螺钉最大等效应力等指标。
结果与结论:①在压缩、弯曲、旋转工况下,螺钉组骨折面最大综合位移分别为0.52,0.27,0.544 mm,联合组骨折面最大综合位移分别为0.51,0.25,0.396 mm,钢板组骨折面最大位移分别为0.495,0.234,0.393 mm;②螺钉组骨折面平均等效应力分别为5.964,4.512,24.176 MPa,联合组骨折面平均等效应力分别为5.651,4.601,21.465 MPa,钢板组骨折面平均等效应力分别为1.210,4.048,      13.537 MPa;③对比可知,钢板组骨折面位移最小,联合组骨折面位移接近钢板组;联合组、螺钉组骨折面平均有效应力均高于钢板组;④结果证实,根据该有限元分析试验结果,可吸收螺钉联合爱昔邦缝线固定长螺旋投弹骨折具有良好的骨折稳定性,同时应力遮挡效应小于钢板固定,有利于骨折愈合、避免局部骨质疏松。
https://orcid.org/0000-0001-5945-0020 (覃万安) 

中国组织工程研究杂志出版内容重点:人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程

关键词: 骨, 肱骨, 骨折, 可吸收螺钉, 有限元分析, 骨折面, 载荷, 等效应力, 综合位移

Abstract: BACKGROUND: There are many effective treatments for humerus shaft fractures caused by grenade throwing, such as non-operative treatment using hanging cast, operative treatment using locking plate, screw and intramedullary nail. However, it is reported by our team for the first time that using absorbable screw and ethibond suture for the treatment.  
OBJECTIVE: To evaluate the stabilization of fractures which are long-spiral humeral shaft fractures caused by grenade throwing fixed with absorbable screws and ethibond sutures in the method of finite element analysis, and provide evidence for clinical application.
METHODS: CT data of humerus of a volunteer in Department of Orthopedics, 923 Hospital of Chinese People’s Liberation Army Joint Logistic Support Force were collected. Finite element models of the same fracture with different fixities which were limited contact dynamic compression plate (plate group), absorbable screws (screw group), and absorbable screws with ethibond sutures (combination group) were established. Three working conditions were set up: (1) humeral head was fixed and distal humerus was applied compressive force of 300 N. (2) Humeral head and distal humerus were fixed and the middle part was applied bending load of 350 N. (3) The humeral head was fixed and distal humerus was applied torsion load of 15 N•m. The maximum displacement of fracture surface, the average equivalent stress of fracture surface and the maximum equivalent stress of absorbable screw were assessed in three working conditions. 
RESULTS AND CONCLUSION: (1) Under compression, bending or torsion loading, the maximum deformations of fracture surface of the model in the screw group were 0.52, 0.27, and 0.544 mm, respectively, and 0.51, 0.25, and 0.396 mm in the model of the combination group. The maximum deformations of fracture surface of the model of the plate group were 0.495, 0.234, and 0.393 mm. (2) The mean values of von-Mises stress distribution of fracture surface of the model of the screw group were 5.964, 4.512, and 24.176 MPa, respectively. They were 5.651, 4.601, and 21.465 MPa in the model of the combination group, and 1.210, 4.048, and 13.537 MPa in the model of the plate group. (3) The total deformation in the plate group was the smallest, and that in the combination group was close to that in the plate group; the average effective stress of the fracture surface in the combination and screw groups was higher than that in the plate group. (4) The results verify that according to the results of the experiment in the method of finite element analysis, the fracture stability is satisfactory if using absorbable screws and ethibond sutures to fixate long-spiral humeral shaft fracture. Moreover, the stress-shielding effect is lower than that of dynamic compression plate, and advantageous for fracture union and preventing partial osteoporosis.

Key words: bone, humerus, fracture, absorbable screw, finite element analysis, fracture surface, load, von-Mises stress, total deformation

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