Schneider E, Sasse S, Schmidt H G, Schümann U
Arbeitsbereich Biomechanik, Technische Universität Hamburg-Harburg.
Unfallchirurg. 1992 Nov;95(11):580-7.
The mechanical behaviour of the circular external fixation device using thin, pre-tensioned wires is difficult to predict, because the individual elements, such as rings, rods and wires, can be assembled in a large variety of configurations. This behaviour is of particular importance in the treatment of large segmental defects and in bone lengthening, because most of the load is transmitted through the fixator. In this study, the mathematical basis of the widely varying definitions of stiffness under axial, bending and torsional loads is presented. The principal variables influencing a particular configuration and their effects are indicated. Particular consideration must be given to the fact that the wires under tension generate a non-linear behaviour of the frame. The information needed for reporting on different fixator systems is indicated. Finally, the effect of individual structural elements, such as number, direction and tension of the wires, number of threaded rods and distance between the planes of the rings on the different stiffnesses, is presented and discussed with respect to clinical significance.
使用细的、预张紧钢丝的环形外固定装置的力学行为难以预测，因为诸如环、杆和钢丝等单个元件可以以多种配置进行组装。这种行为在治疗大段骨缺损和骨延长中尤为重要，因为大部分载荷通过固定器传递。在本研究中，给出了在轴向、弯曲和扭转载荷下刚度定义广泛变化的数学基础。指出了影响特定配置的主要变量及其影响。必须特别考虑到受拉钢丝会使框架产生非线性行为这一事实。指明了报告不同固定器系统所需的信息。最后，针对临床意义，介绍并讨论了诸如钢丝的数量、方向和张力、螺纹杆的数量以及环平面之间的距离等单个结构元件对不同刚度的影响。
