Sod Gary A, Hubert Jeremy D, Martin George S, Gill Marjorie S
From the Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
Vet Surg. 2005 Nov-Dec;34(6):594-603. doi: 10.1111/j.1532-950X.2005.00093.x.
To compare the monotonic biomechanical properties of a prototype equine third metacarpal dynamic compression plate (EM-DCP) fixation with a double broad dynamic compression plate (DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones.
In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation.
Twelve pairs of adult equine cadaveric MC3 bones.
Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for (1) 4-point bending single cycle to failure testing, (2) 4-point bending cyclic fatigue testing, and (3) torsional testing. The EM-DCP (10-hole, 4.5 mm) was applied to the dorsal surface of one randomly selected bone from each pair. Two DCPs, 1 dorsally (10-hole, 4.5 mm broad) and 1 laterally (9-hole, 4.5 mm broad) were applied to the contralateral bone from each pair. All plates and screws were applied using standard AO/ASIF techniques to MC3 bones that had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P<.05.
Mean 4-point bending yield load, yield bending moment, bending composite rigidity, failure load and failure bending moment of the EM-DCP fixation were significantly greater (P<.0001) than those of the double broad DCP fixation. Mean cycles to failure in 4-point bending of the EM-DCP fixation was significantly greater (P<.0008) than that of the double broad DCP fixation. Mean yield load, composite rigidity, and failure load in torsion of the EM-DCP fixation were significantly greater (P<.0035) than that of the double broad DCP fixation.
The EM-DCP provides increased stability in both static overload testing and cyclic fatigue testing.
Results of this in vitro study support the conclusion that the prototype EM-DCP fixation is biomechanically superior to the double broad DCP fixation for the stabilization of osteotomized equine MC3.
比较一种原型马第三掌骨动力加压钢板（EM-DCP）固定与双宽动力加压钢板（DCP）固定修复马第三掌骨（MC3）截骨的单调生物力学特性。
对成对的马MC3尸体进行体外生物力学测试，进行骨干中段截骨，采用两种骨折固定方法之一进行稳定固定。
12对成年马尸体的MC3骨。
将12对马MC3分为3个测试组（每组4对），分别进行（1）4点弯曲单循环至破坏测试、（2）4点弯曲循环疲劳测试和（3）扭转测试。将EM-DCP（10孔，4.5mm）应用于每对中随机选择的一根骨的背侧表面。将两块DCP，一块背侧（10孔，4.5mm宽）和一块外侧（9孔，4.5mm宽）应用于每对的对侧骨。所有钢板和螺钉均采用标准AO/ASIF技术应用于骨干中段截骨的MC3骨。使用配对t检验比较每组中每种方法的平均测试变量值。显著性设定为P<0.05。
EM-DCP固定的平均4点弯曲屈服载荷、屈服弯矩、弯曲复合刚度、破坏载荷和破坏弯矩均显著高于双宽DCP固定（P<0.0001）。EM-DCP固定在4点弯曲中的平均破坏循环次数显著高于双宽DCP固定（P<0.0008）。EM-DCP固定在扭转中的平均屈服载荷、复合刚度和破坏载荷显著高于双宽DCP固定（P<0.0035）。
在静态过载测试和循环疲劳测试中，EM-DCP均能提供更高的稳定性。
这项体外研究的结果支持以下结论，即原型EM-DCP固定在稳定马MC3截骨方面在生物力学上优于双宽DCP固定。
