天鹅型记忆接骨器治疗肱骨骨折和骨不连的生物力学研究

目的：研究天鹅型记忆接骨器（SMC）治疗骨折骨不连的生物力学特征。方法：利用电测、二维（2D）、三维（3D）光弹性技术，通过贴片，标定电测得到SMC的载荷－应变曲线，并通过固定新鲜人体肱骨，计算SMC的动态记忆持骨力值；通过2D光弹性技术计算SMC鹅颈加压部动态记忆加压力值，用精密浇铸法得到肱骨环氧树脂3D光弹性模型，模仿临床使用，得到SMC固定下的肱骨模型3D应力场分布，同时利用Leize偏光显微镜结合三维光弹法，计算肱骨模型考察点3D应力场中的6个应力分量。结果：电测SMC动态记忆持骨的生物学力值为110．35N。2D光弹测得纵向动态记忆加压力为163．88N。3D光弹测得SMC的鹅颈－加压部、鹅体－接骨板部、鹅翼－持骨部三部相互协调，记忆持骨，形成动态3D立体固定，产生全场应力分布。3D应力分离表明SMC固定后骨折端的应力基本为正应力。结论：SMC空间立体记忆固定的应力场，有利于骨折、骨不连的治疗、允许早期功能锻炼并促进骨愈合。

Biomechanical study of swan-like memory compressive connector for treating fractures and nonunions of humerus

Objective:To study the biomechanical basis of swan like memory compressive connector (SMC) for treating fractures and nonunions of humerus. Methods:The study was performed by electrometric, two and three dimensional (3D) photoelasticity techniques. By gauging and multiple time standardization, load strain curve was got, then the dynamic memory force of SMC was calculated. The dynamically compressive force of swan neck compressive part was calculated by 2D photoelasticity. By precision moulding, the epoxy resin 3D photoelasticity humeral model was established, then it was fixated by SMC, meanwhile, an epoxy resin cirque was used to share the continuously memorial compress. The 3D stress distribution of humeral model was got, and 6 space component stress of the inspected node was divided by Leize polarizing microscope. Results:The continuously memory force of SMC was 110.35 N. The longitudinal dynamical compressive memory force was 163.88 N. 3D photoelasticity method showed that the swan neck compressive part of SMC, swan body connecting part of SMC and swan wing holding part of SMC were in consistent with each other, memorably holding bone, 3D fixation style was formed, and overall stress distribution was produced.. Conclusion:The stress field produced by 3D memory fixation of SMC is good for the treatment of fractures and nonunions. Early function exercises are allowed, and the fracture healing is prompted.