肱骨外侧髁骨折的生物力学研究(英文)

Biomechanical characteristics of fracture of humeral ectocondyle

背景:肱骨外侧髁骨折是最易发生的肘部损伤之一,属关节内骨骺骨折,临床上对其骨折发生和其治疗的力学机制并不完善。目的:从生物力学角度研究肱骨外侧髁在不同体位加载下的应力分布规律,探讨其骨折发生治疗机制。设计:计算机模拟应力研究。单位:福州大学实验力学教研室和北京大学第三医院骨科。材料:实验于2000-01/2002-12在福州大学福建实验力学专业委员会完成,选择6岁儿童尸体肱骨标本(福建中医学院解剖教研室提供),使用仪器包括计算机,SUPER-SAP93软件,材料切割机,骨角度测量仪等。方法:模拟伸屈肘及前臂旋前、中立、旋后等多种体位加载在三维有限元模型上,计算分析相应部位的应力分布状况。主要观察指标:肱骨外髁和肱骨滑车部位的平均Mises应力值。结果:半屈肘位时肱骨外侧髁区平均应力值最大,而伸肘时的伸肌腱作用节点应力值大于外侧髁区。结论:半屈肘位时肱骨外侧髁骨折的发生以尺桡骨撞击力与重力的上下剪切作用为主;伸肘位时以伸肌腱牵拉为主的弯力偶矩可拉脱外侧髁形成骨折。肱骨外侧髁骨折的复位可利用伸肌腱的牵拉作用,而固定则尽量避免伸肌腱的牵拉。

BACKGROUND： Fracture of humeral ectocondyle is a kind of articular epiphyseal fracture. It is one of the most prevalent disorder of cubital articulation. The occurrence of fracture and the mechanical mechanism of treatment is not very well cognized in clinic. OBJECTIVE： To analyze the stress distribution of the humeral ectocondyle in different postures so as to investigate the treatment mechanism of the humeral ectocondyle fracture. DESIGN： Computer simulation study on stress. SETTING： Department of Experimental Mechanics, Fuzhou University, and Department of Orthopedics, Third Affiliated Hospital of Peking University. MATERIALS： This experiment was conducted in the Fujian Experimental Mechanic Committee of Fuzhou University between January 2000 and December 2002. Humerus from a 6-year-old corpse （Provided by the Department of Anatomy of Fujian College of Traditional Chinese Medicine）. Instruments were computer, SUPER-SAP93 software, material sickle and measuring instrument and so on. METHODS： 9 kinds of loading conditions were simulated and added on three dimensional finite elemental model of humerus in SUPER-SAP93 software, and then the stress distribution was filed out and analyzed. MAIN OUTCOME MEASURES： The average Mises stress of lateral condylar area and humeral trochlea area. RESULTS： At flection posture of elbow, the average Mises stress of lateral condylar area was the largest while at extension posture the stresses of nodes affected by extensor tendon were larger than those of lateral condyle. CONCLUSION： At the flection posture of elbow, the fracture of lateral condyle of humerus was resulted from collision occurring when radius and ulna struck humerus while at extension posture, it was chiefly due to extensor tractive force. We can use extensor tractive force to reduce the fracture of lateral condyle and avoid extensor tractive force to fix it.