Sod Gary A, Mitchell Colin F, Hubert Jeremy D, Martin George S, Gill Marjorie S
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
Vet Surg. 2008 Apr;37(3):283-8. doi: 10.1111/j.1532-950X.2008.00378.x.
To compare monotonic biomechanical properties and fatigue life of a broad locking compression plate (LCP) fixation with a broad limited contact dynamic compression plate (LC-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.
Cadaveric adult equine MC3 bones (n=12 pairs).
MC3 were divided into 3 groups (4 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. The 8-hole, 4.5 mm LCP was applied to the dorsal surface of 1 randomly selected bone from each pair. One 8-hole, 4.5 mm LC-DCP) was applied dorsally to the contralateral bone from each pair. All plates and screws were applied using standard ASIF techniques. All MC3 bones 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 yield load, yield bending moment, composite rigidity, failure load and failure bending moment, under 4-point bending, single cycle to failure, of the LCP fixation were significantly greater than those of the LC-DCP fixation. Mean cycles to failure for 4-point bending was significantly greater for the LCP fixation compared with LC-DCP fixation. Mean yield load, mean composite rigidity, and mean failure load under torsional testing, single cycle to failure was significantly greater for the broad LCP fixation compared with the LC-DCP fixation.
The 4.5 mm LCP was superior to the 4.5 mm LC-DCP in resisting the static overload forces (palmarodorsal 4-point bending and torsional) and in resisting cyclic fatigue under palmarodorsal 4-point bending.
The results of this in vitro study may provide information to aid in the selection of a biological plate for the repair of equine long bone fractures.
比较宽型锁定加压钢板（LCP）固定与宽型有限接触动力加压钢板（LC-DCP）固定修复马第三掌骨（MC3）截骨的单调生物力学性能和疲劳寿命。
对配对的马MC3尸体进行体外生物力学测试，采用两种骨折固定方法之一对骨干中段截骨进行稳定固定。
成年马MC3尸体骨（n = 12对）。
将MC3分为3组（每组4对）进行：（1）4点弯曲单周期破坏试验；（2）4点弯曲循环疲劳试验；（3）扭转单周期破坏试验。将8孔、4.5 mm的LCP应用于每对中随机选择的1块骨的背侧表面。将一块8孔、4.5 mm的LC-DCP背侧应用于每对的对侧骨。所有钢板和螺钉均采用标准的ASIF技术应用。所有MC3骨均有骨干中段截骨。每组内使用配对t检验比较每种方法的平均测试变量值。显著性设定为P<0.05。
在4点弯曲单周期破坏试验中，LCP固定的平均屈服载荷、屈服弯矩、复合刚度、破坏载荷和破坏弯矩均显著大于LC-DCP固定。与LC-DCP固定相比，LCP固定的4点弯曲平均破坏周期显著更长。在扭转试验单周期破坏中，宽型LCP固定的平均屈服载荷、平均复合刚度和平均破坏载荷显著大于LC-DCP固定。
4.5 mm的LCP在抵抗静态过载力（掌背4点弯曲和扭转）以及掌背4点弯曲下抵抗循环疲劳方面优于4.5 mm的LC-DCP。
这项体外研究的结果可能为选择用于修复马长骨骨折的生物钢板提供信息。
