Pugh K J, Wolinsky P R, Dawson J M, Stahlman G C
Department of Surgery, University of Kentucky, Lexington 40536-0284, USA.
J Orthop Trauma. 1999 Jan;13(1):20-6. doi: 10.1097/00005131-199901000-00006.
The objective of this study was to ascertain which factors determine the rigidity of a hybrid external fixation frame in a tibial periarticular fracture model.
Laboratory investigation using a polyvinylchloride pipe periarticular tibia fracture model.
Simulated periarticular tibia fractures were created in a tibia model. Instrumented specimens were tested in a biomaterials testing system.
Groups of simulated periarticular tibia fractures were stabilized with one of nine different external fixation constructs with components from one manufacturer.
Elastic stiffness was measured for each specimen in compression, torsion, flexion bending, extension bending, and varus and valgus bending.
The four-ring Ilizarov fixator was the stiffest in all modes of testing. There was a trend toward increasing stiffness with an increasing number of rings. Fixators constructed with multiple levels of fixation in the periarticular fragment were stiffer in all modes of testing. The additional spacing between wires gained by the use of a single thick carbon ring or the use of a drop wire three centimeters from a single ring did not increase stiffness in this model. Frame modifications intended to augment the bar-to-ring connection did not increase stiffness. The use of rings mounted with half-pins instead of a unilateral bar mounted with half-pins for diaphyseal fixation increased the stiffness of the frame only in torsional testing.
Although the ideal stiffness of an external fixator is unknown, our results show that the addition of more than one level of fixation in the periarticular fragment increases the stiffness of hybrid external fixators in this periarticular tibia fracture model. Augmentation of the ring-to-bar connection did not significantly affect the stiffness of the frame.
本研究的目的是确定在胫骨关节周围骨折模型中，哪些因素决定混合外固定架的刚度。
使用聚氯乙烯管胫骨关节周围骨折模型进行实验室研究。
在胫骨模型中制造模拟的关节周围胫骨骨折。对仪器化的标本在生物材料测试系统中进行测试。
将模拟的关节周围胫骨骨折组用来自同一制造商的九种不同外固定结构之一进行固定。
测量每个标本在压缩、扭转、屈曲弯曲、伸展弯曲以及内翻和外翻弯曲时的弹性刚度。
四环伊里扎洛夫固定架在所有测试模式中刚度最大。随着环数增加，刚度有增加的趋势。在关节周围骨折块采用多级固定构建的固定架在所有测试模式中刚度更大。在该模型中，使用单个厚碳环或在距单个环三厘米处使用吊线所获得的钢丝之间的额外间距并未增加刚度。旨在增强杆与环连接的框架改进并未增加刚度。在骨干固定中使用装有半针的环代替装有半针的单侧杆仅在扭转测试中增加了框架的刚度。
尽管外固定架的理想刚度尚不清楚，但我们的结果表明，在关节周围骨折块增加一级以上的固定可增加该胫骨关节周围骨折模型中混合外固定架的刚度。环与杆连接的增强对框架刚度没有显著影响。
