角棒与圆棒在椎弓根螺钉固定系统中抗旋转能力的生物力学比较

Biomechanical evaluation of rotation torque with polygonal and round rod on pedicle screw fixations

中文关键词:  椎弓根螺钉  角棒  去旋转  扭矩

英文关键词:Pedicle screw  Polygonal rod  Rotation  Correction torque

中文摘要:

  【摘要】 目的：比较角棒与圆棒在Legacy、USSⅡ、RF单轴向椎弓根螺钉固定系统中的抗旋转性能。方法：将Legacy、USSⅡ、RF单轴向椎弓根螺钉分别与原装圆棒或自行设计的角棒组合，分为6个实验组：（1）Legacy螺钉和Legacy圆棒组（A组）；（2）Legacy螺钉和角棒组（B组）；（3）USSⅡ螺钉和USSⅡ圆棒组（C组）；（4）USSⅡ螺钉和角棒组（D组）；（5）RF螺钉与RF圆棒组（E组）；（6）RF螺钉和角棒组（F组）。每组7套，其中1套行预试验。分别以固定的扭矩标准锁紧单枚椎弓根螺钉与圆棒或角棒，在MTS 858试验机上测量旋转滑动扭矩。结果：A、B组的旋转滑动扭矩分别为12.3±1.9Nm和16.9±2.1Nm；C、D组的旋转滑动扭矩分别为3.9±0.8Nm和4.6±0.7Nm；F、F组的旋转滑动扭矩分别为6.7±0.4Nm和17.6±0.7Nm。Legacy螺钉与ＲＦ螺钉配角棒组的旋转滑动扭矩高于配圆棒组（Ｐ<0.05），USSⅡ螺钉配两种棒的旋转滑动力矩无显著性差异（Ｐ＞0.05）。结论：角棒能显著提高Legacy和RF椎弓根螺固定系统的抗旋转能力。

英文摘要:

  【Abstract】 Objective：To compare rotation torque between round rod and polygonal rod on Legacy，USSⅡ and RF pedicle screw instrument.Method：Six test groups were designed as follows：（1）Legacy screw plus Legacy round rod（group A）；（2）Legacy screw plus polygonal rod（group B）；（3）USSⅡ screw plus USSⅡ round rod（group C）；（4）USSⅡ screw plus polygonal rod（group D）；（5）RF screw plus RF round rod（group E）；（6）RF screw plus polygonal rod（group F）.Each group had 7 monoaxial pedicle screws and one round or polygonal rod，each time one screw was tightened on rod with constant torque.MTS 858 testing system was used to record the rotation torque，MNOVA was used for analysis.Result：The average of rotational torque of group A and B was 12.3±1.9Nm and 16.9±2.1Nm respectively，3.9±0.8Nm and 4.6±0.7Nm respectively for group C and D，6.7±0.4Nm and 17.6±0.7Nm for group E and F respectively.The rotational torque of polygonal rod plus Legacy screw and RF screw were significantly higher than round rod（P<0.05）.The rotational torque between polygonal and round rod plus USSⅡ screw showed no significant difference（P>0.05）.Conclusion：Polygonal rod can significantly increase the rotation torque of Legacy and RF pedicle screw system.