Shahar R
Section of Surgery, Veterinary Teaching Hospital, Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Israel.
Vet Surg. 2000 Jan-Feb;29(1):59-69. doi: 10.1111/j.1532-950x.2000.00059.x.
To compare the stiffness and pin stresses of three sizes of external fixator systems with stainless-steel and acrylic connecting bars.
Finite element analysis.
Small, medium, and large external fixator systems of type I and type II configurations were modeled for finite element analysis. Each model was evaluated with a standard stainless-steel and three different diameters of acrylic connecting bar. Displacements and stresses were calculated for the loading modes of axial compression, medio-lateral bending, cranio-caudal bending, and torsion. The location of the pin experiencing maximum stress was determined for all configurations and loading modes.
Acrylic column diameters of 9.53 mm for the small external fixator system and 15.9 mm for the medium external fixator system provide equivalent stiffness and maximum pin stresses to those provided by the standard stainless-steel connecting bars (3.2- and 4.8-mm diameter, respectively). The largest diameter acrylic column tested (31.75-mm) produced lower stiffness and higher maximum pin stresses than the standard stainless-steel connecting bar (11.1-mm diameter).
When applying a small or medium external fixator, an acrylic column of 9.53-mm or 15.9-mm diameter, respectively, can be used. For a large external fixator system, an acrylic column of diameter >31.75 mm is required.
The sizes of acrylic connecting bars for use in small and medium external fixator systems have been determined. Large systems should incorporate the standard stainless-steel connecting bar.
比较三种尺寸的外固定器系统（配备不锈钢和丙烯酸连接杆）的刚度和针应力。
有限元分析。
对I型和II型配置的小型、中型和大型外固定器系统进行建模，以进行有限元分析。每个模型均采用标准不锈钢和三种不同直径的丙烯酸连接杆进行评估。计算轴向压缩、中外侧弯曲、颅尾侧弯曲和扭转加载模式下的位移和应力。确定所有配置和加载模式下承受最大应力的针的位置。
小型外固定器系统的丙烯酸柱直径为9.53 mm，中型外固定器系统的丙烯酸柱直径为15.9 mm，其刚度和最大针应力与标准不锈钢连接杆（直径分别为3.2 mm和4.8 mm）相当。测试的最大直径丙烯酸柱（31.75 mm）的刚度低于标准不锈钢连接杆（直径11.1 mm），最大针应力更高。
应用小型或中型外固定器时，可分别使用直径为9.53 mm或15.9 mm的丙烯酸柱。对于大型外固定器系统，需要直径>31.75 mm的丙烯酸柱。
已确定用于小型和中型外固定器系统的丙烯酸连接杆尺寸。大型系统应采用标准不锈钢连接杆。
