形状记忆锯齿臂环抱内固定器的实验研究与临床应用

An experlimental study and preliminary clinical reportof shape-menmory sawtooth-arm embracing internal fix-ator

使用镍钛形状记忆合金制成锯齿臂环抱内固定器，后者由体部、臂部和锯齿部三部分组成。在横截面上，臂与体部围成２／３圆弧，且臂端超过半圆部分向内弯转，以适应截面非正圆的长骨干固定需要。环抱器有圆柱形和圆锥形两种，分别用于长骨干中段或其上或下１／３。动物实验与体外力学试验证实，环抱器有良好的抗弯和抗扭作用，而对压缩应力的对抗作用明显低于接骨板，有利于促进骨折愈合和减少固定后骨质疏松，为长骨干骨折提供了一种新的、操作简单的有效治疗手段。临床应用１７例（股骨、肱骨、桡骨、尺骨骨折），效果满意。

AbstractThesawtooth-arm internal embracing fixator ismade of Nickel-Titanium shape memory alloy and con-sists of 3 components:body,arms and sawteech.Incross section a 2/3 circumference is constructed bybody and arms of the fixator.The free ends of thearms which exceed the semi-circle are bended more me-dially so that it can match the requirement of fixation oflong tubular bone whose cross section is not a regularcircle. The embracing fixator has two types:the cylin-der type is for use in the middle part and the cone typeis either for the proximal or distal 1/3 of the shaft oflong tubular bone. The animal experimental studiesand in vitro mechanicaI tests demonstrated that the em-bracing fixator possesses good anti-bending and anti-torsion effects,and its resisting compression efect wasmuch lower than that of bone plate. These characteris-tics are beneficial for enhancing fracture healing,reducing post fixation osteoporosis and providing anew, simple and effective method for the treatment oflong tubular bone fracture. The fixator has alreadybeen used in the treatment of fractures of femur,humerus, radius and uIna with good resuIts.