不同附加钢板治疗股骨干髓内钉固定术后骨不连的生物力学比较研究

Different modes of augmentative plating for femoral shaft nonunion after intramedullary nailing:a biomechanical comparison

目的比较不同附加钢板技术治疗股骨干髓内钉固定术后骨不连的抗旋转稳定性。方法将15根人工合成股骨制作成旋转不稳定型股骨干髓内钉固定术后骨不连模型。随机分成3组(n=5):对照组1:采用外置锁定加压钢板固定;对照组2:采用前置锁定加压钢板固定;实验组:采用前置多维交叉锁定钢板固定。予以扭转负荷加载试验,扭转负荷从0 N·m开始,加载至10 N·m,加载速度为6°/min,记录并比较3组模型的扭转角度和刚度。结果在扭转负荷下,对照组1、对照组2和实验组模型的扭转角度分别为9.69°±0.34°、7.15°±0.20°、1.59°±0.02°,差异有统计学意义(P=0.002);实验组模型的扭转角度显著小于对照组1模型,差异有统计学意义(P<0.05)。对照组1、对照组2和实验组模型的的扭转刚度分别为(1.02±0.04)、(1.39±0.04)、(6.16±0.06)N·m/°,差异有统计学意义(F=14886.140,P<0.001);3组之间两两比较差异均有统计学意义(P<0.05)。结论当采用附加钢板治疗股骨干髓内钉固定术后骨不连时,相比外置附加钢板,前置附加钢板能够明显提高骨不连断端的抗旋转稳定性。相比锁定加压钢板,多维交叉锁定钢板能更好地实现螺钉的双皮质固定,其抗旋转稳定性最好。

Objective To compare the anti-rotation stability between different modes of augmentative plating for femoral shaft nonunion after intramedullary nailing.Methods Fifteen artificial synthetic femurs were used to create models of femoral shaft nonunion with rotational instability after intramedullary nailing.They were randomly divided into 3 groups(n=5).Control group 1 was fixated with lateral locking compression plate(LCP),control group 2 with anterior LCP,and the experimental group with anterior multi-dimensional cross locking plate(MDC-LP).After fixation,all the groups were subjected to a torsional loading test,with the torsional loading starting from 0 N·m till 10 N·m and a loading speed of 6°/min.The 3 model groups were compared in terms of torsional angle and stiffness.Results Under the torsion loading,the torsional angles for control group 1,control group 2 and the experimental group were 9.69°±0.34°,7.15°±0.20°and 1.59°±0.02°,respectively,showing significant differences(P=0.002);the torsional angle for the experi mental group was significantly smaller than that for control group 1(P<0.05).The torsion stiffness for control group 1,control group 2 and the experimental group was respectively 1.02 N·m/°±0.04 N·m/°,1.39 N·m/°±0.04 N·m/°and 6.16 N·m/°±0.06 N·m/°,showing significant differences(P=14886.140,P<0.001);there was a significant difference between any 2 groups(P<0.05).Conclusions In the management of femoral shaft nonunion after intramedullary nailing,anterior augmentative plating can provide better anti-torsional stability than lateral augmentative plating,and MDC-LP can also provide better anti-torsional stability than a conventional LCP because it leads to bicortical fixation of the screws.