Oni O O, Capper M, Soutis C
Department of Orthopaedic Surgery, Glenfield General Hospital, Leicester, England.
J Orthop Trauma. 1995 Feb;9(1):83-8. doi: 10.1097/00005131-199502000-00013.
In an attempt to reduce pin loosening, a flanged external fixator pin has been designed and its bending stiffness has been compared with that of a standard pin. The pins were inserted into pilot holes previously drilled into a piece of teak hardwood. Loads of different magnitudes were applied at a fixed moment arm and force-deflection curves were obtained. Thereafter, percentage stiffness increase was calculated for each pilot hole size. The results show that the addition of a collar to the external fixator pin increases its stiffness and its ability to resist bending forces. In a parallel study, the stresses generated at the pin-bone interface by this pin and a standard pin were compared using finite element analysis techniques. The results show that the flange significantly reduced the stresses generated at the pin-bone interface. In addition, stresses were dissipated over a wider area.
为了减少钢针松动，设计了一种带凸缘的外固定器钢针，并将其弯曲刚度与标准钢针进行了比较。将钢针插入预先钻在一块柚木硬木中的导向孔中。在固定的力臂上施加不同大小的载荷，并获得力-挠度曲线。此后，针对每个导向孔尺寸计算刚度增加百分比。结果表明，给外固定器钢针增加一个套环可提高其刚度及其抵抗弯曲力的能力。在一项平行研究中，使用有限元分析技术比较了这种钢针和标准钢针在针-骨界面处产生的应力。结果表明，凸缘显著降低了针-骨界面处产生的应力。此外，应力在更广泛的区域消散。
