智能气囊小夹板治疗桡骨远端伸直型关节内骨折的三维有限元分析研究

Three dimensional finite element analysis of intra-articular fracture of distal radius extension type treated by small splint with intelligent airbag

目的:运用三维有限元(FE)对自行研制的智能气囊小夹板治疗桡骨远端伸直型关节内骨折的力学稳定性进行分析,评价其治疗有效性。方法:将1位26岁健康成年男性志愿者前臂通过智能气囊小夹板固定于掌屈尺偏位,CT扫描获得数据通过Imageware 13.0、Mimics 15.0、Ansys Workbench 15.0等软件建模分析,模型均施加100N轴向恒定载荷及28KPa基础约束载荷,骨折采用AO分型,对不同骨折模型夹板固定后的应力分布进行研究,分析试验夹板的生物力学有效性。结果:构件应力云图分布示,由于腕部软组织薄,应力主要集中于桡腕关节处。C2.3,C3.2,C3.3型骨折由于骨折块数量较多、较小,在载荷条件下,其骨折固定轴向稳定性较差。而对于C1.1,C1.2,C1.3,C2.1,C2.2及C3.1型骨折力学较稳定。气囊压垫在骨折端的基础压强在0.28-0.50KPa之间,纠正移位在1cm内的骨折块需调高基础压强0.13-0.22KPa。结论:智能气囊夹板对C1.1,C1.2,C1.3,C2.1,C2.2及C3.1型桡骨远端伸直型骨折生物力学稳定性较高,通过调节夹板气囊压垫压强可有效防止和纠正骨折块移位。

Objective:To analyze the mechanical stability of intra-articular fracture of distal radial extension type treated by self-developed small splint with intelligent airbag throughthree dimensional finite element(FE) and evaluate the therapeutic efficacy.Methods:The forearm of a 26-year-old healthy adult male volunteer was fastened to the wrist flexion and ulnar position by small splint with intelligent airbag and scanned by the CT.The data obtained by CT scan were modeled and analyzed through Imageware 13.0,Mimics 15.0 and Ansys Workbench 15.0 software.The model was subjected to 100 N axial constant load and 28 KPa basic constrained load.The AO classification was used to study fracture.The stress distribution of different fracture models after using splint fixation was studied and the bio-mechanical efficacy of splint was analyzed.Results:The stress distribution of the components showed that the stress was mainly concentrated on the radiocarpal joint because of the thin wrist soft tissue.Under load conditions,the axial stability of fracture fixation for the C2.3,C3.2,C3.3 types of fracture was poor due to the larger number and smaller volume of fracture fragments.While the fracture mechanics was more stable for C1.1,C1.2,C1.3,C2.1,C2.2 and C3.1 types of fracture.The basic pressure at the fracture ends by airbag pad was between 0.28 and 0.5KPa.Correction of displacement of the fracturefragment within 1cm needed to increase the basic pressure by 0.13-0.22 KPa.Conclusion:Small splint with intelligent airbag has high bio-mechanical stability for the C1.1,C1.2,C1.3,C2.1,C2.2 and C3.1 types of distal radius extension fracture.It can effectively prevent and correct the fracture fragment displacement by adjusting the pressure of the splint airbag pad.