Eichinger Josef K, Herzog Joshua P, Arrington Edward D
Department of Orthopedics and Rehabilitation, Womack Army Medical Center, Fort Bragg, North Carolina, USA.
Orthopedics. 2011 Jan 3;34(1):19. doi: 10.3928/01477447-20101123-13.
The purpose of this study was to determine if the use of screw hole inserts in empty locking screw holes improves the strength and failure characteristics of locking plates. Twenty 5-hole 1/3 tubular locking plates (Synthes, Paoli, Pennsylvania) were mounted on an oak dowel with a 1-cm gap simulating a fracture with comminution and bone loss. Ten of the 1/3 tubular plates had a screw hole insert placed in the center hole (centered over the simulated fracture), while 10 of the 1/3 tubular plates remained empty in the center hole. The plate-dowel constructs were placed in an Instron 8800 Material Testing Machine and subjected to a series of loading conditions, replicating physiologic loading. The torsional and axial stiffness of each plate-dowel construct was calculated. All plates were then loaded to failure. No significant differences were found in the mechanical properties of the 2 plate constructs. Both the filled screw-hole plate constructs and unfilled screw hole plate constructs demonstrated the same torsional and axial stiffness, before and after being subjected to a combined cyclic and axial torsional load. Additionally, there was no significant difference in ultimate compressive strength or load to failure. Locking plate technology is a relatively new innovation in orthopedic fracture fixation. The evolution of new and varied applications and implants continues. Persistent, fundamental questions exist concerning the basic locking plate design. This study demonstrates that the addition of screw hole inserts does not significantly change the stiffness, torsional strength, or axial loading strength of 1/3 tubular locking plates.
本研究的目的是确定在空的锁定螺孔中使用螺孔插入物是否能提高锁定钢板的强度和失效特性。二十块5孔1/3管状锁定钢板（辛迪斯公司，宾夕法尼亚州波利）被安装在一个橡木销钉上，两者之间有1厘米的间隙，模拟粉碎性骨折和骨缺损的骨折情况。其中10块1/3管状钢板在中心孔（模拟骨折的中心位置）放置了一个螺孔插入物，而另外10块1/3管状钢板的中心孔保持为空。将钢板 - 销钉结构放置在英斯特朗8800材料试验机中，并施加一系列加载条件，模拟生理加载。计算每个钢板 - 销钉结构的扭转刚度和轴向刚度。然后对所有钢板加载直至失效。两种钢板结构的力学性能未发现显著差异。无论是填充螺孔的钢板结构还是未填充螺孔的钢板结构，在承受联合循环和轴向扭转载荷之前和之后，都表现出相同的扭转刚度和轴向刚度。此外，极限抗压强度或失效载荷也没有显著差异。锁定钢板技术是骨科骨折固定领域一项相对较新的创新。新型和多样化的应用及植入物不断涌现。关于基本锁定钢板设计仍存在一些持续的、根本性的问题。本研究表明，添加螺孔插入物并不会显著改变1/3管状锁定钢板的刚度、扭转强度或轴向加载强度。
