螺钉数目对钢板应变及结构刚度的影响

The Influence of the Number of Screws on Bending Stiffness and DCP Strain in an in Vitro Fracture Model

目的探讨螺钉数量对钢板应变和结构刚度的影响。方法三十根栗木条，随机分成5组，螺钉固定位置：A组固定1、6；B组固定1～2、6；C组固定1～3、6；D组固定1～4、6；E组固定1～6。进行三点折弯实验，实验数据行统计分析。结果A、B、C、D及E组各样本其结构刚度、钢板中央应变无显著差异（P〉0．05），但A组样本钢板表面总的应变比其它组总的应变大（P〈0．05），其余组间两两比较无差异。结论已定钢板长度及工作长度，螺钉数目对钢板中央应变及抗弯刚度无明显影响，但钢板总应变随螺钉数目的减少而增加。

Objective To investigate the effect of the number of screws on the bending stiffness and dynamic compression plate（DCP）strain in an in vitro transverse fracture model. Methods Thirty wooden sticks of the chestnut were separated into five groups at random, Screw position of the five groups were：A 1,6;B 1～2,6;C 1～3,6;D 1～4,6;E 1～6. Thirty plate-screw constructs were test respectively, all strain readings of plate, were compared each other. Results No significant difference about the bending stiffness and median plate strains in three point bending whilst the total plate strains in A were significantly higher than those in the other groups（P〈0.0S）. Conclusion This study showed that the symmetrical omission of screws, with a given plate length and working length, would not affect significantly the bending stiffness and median plate strain while the total plate surface strains might increase.