螺钉数量对动力加压钢板应变和弯曲刚度的影响  

The Effect of the Number of Screws on Strain and Bending Stiffness of the Dynamic Compression Plate Strain

作　　者：黄勇全[1] 舒勇[2] 李浩[3] 黄华伟[1] 陈文明[1] 

机构地区：[1]萍乡市人民医院骨科,江西萍乡337000 [2]南昌大学第一附属医院骨科,南昌330006 [3]中国人民解放军第九四医院骨科,南昌330002

出　　处：《江西医学院学报》2009年第7期52-55,共4页Acta Academiae Medicinae Jiangxi

摘　　要：目的研究体外模拟横断骨折模型中螺钉数量对动力加压钢板(DCP)应变和弯曲刚度的影响。方法30根用C620车床加工成长320 mm、Φ24 mm栗木条随机分为A、B、C、D、E 5组,每组6条。各组栗木条模拟中央横断骨折,一块十二孔的DCP对称性固定,3个应变片沿钢板表面纵行黏贴。螺钉固定位置:A组固定1-6;B组固定1-2-6;C组固定1-2-3-6;D组固定1-2-3-4-6;E组固定1-2-3-4-5-6。各组分别在微机控制电子万能实验机上进行载荷来自钢板同侧垂直于钢板平面长轴方向的三点折弯实验。结果B、C、D、E 4组50、100、150、200 N第1、3应变片的应变值与A组比较差异均无统计学意义(均P>0.05),而第2应变片的应变值与A组比较差异均有统计学意义(均P<0.05)。弯矩下的弯曲刚度:A组(978.0±43.5)N.cm/度,B组(987.0±33.2)N.cm/度,C组(990.0±51.7)N.cm/度,D组(995.0±61.2)N.cm/度,E组(995.0±43.1)N.cm/度,各组间比较差异均无统计学意义(均P(0.05)。B、C、D、E 4组100、1502、00 N钢板表面平均应变值均小于A组(均P<0.05),B、C、D 3组100、150、200 N钢板表面平均应变值与E组比较差异均无统计学意义(均P>0.05)。结论在模拟单纯横断骨折的模型中行三点折弯测试,固定DCP长度及其工作长度,螺钉数量对DCP中央应变及弯曲刚度无明显影响,而对称性减少螺钉数量,DCP平均应变可能增加。Objective To study the effect of the number of screws on the bending stiffness and dynamic compression plate （DCP） strain in a transverse fracture model in vitro. Methods A total of thirty wooden sticks of the chestnut, which were made into round sticks,320 mm in length and 24 mm in diameter,followed by random division into A,B,C,D,E five groups,each including six pieces （n=6）. Simulated median transverse fracture was made, a twelve-hole DCP was attached symmetrically and three rectangular strain gauges were installed longitudinally alongside the compression side of the DCP to measure the surface strain of DCP in response to three-point bending test, each construct loaded respectively by microcomputer control electron universal testing machines. Screws were fixed in various positions in the five groups： 1--6 for group A, 1--2--6 for group B,1--2--3--6 for group C, 1--2--3--4--6 for group D,and 1--2--3--4--5--6 for group E. Each group was subjected to three-point bending test through sustaining the same-side load which was perpendicular to the long axis of the DCP. Results The strain values of location 1 and location 3 with the load of 50,100,150,200 N in group A showed no significant difference compared to the group B, C,D,and E（P〈0.05 respectively） ;whilst significant difference was observed in location 2（P〈0.05 respectively）. The mean bending stiffness in three-point bending test respectively was：group A （978.0±43.5）N · cm/degree,group B（987.0±33.2）N· cm/degree, group C （990. 0 ± 51. 7） N · cm/degree, group D （995. 0 ±61. 2） N· cm/degree, group E （995.0±43.1）N · cm/degree. There wasn＇t significant difference in the bending stiffness between the groups（P〈0.05 respectively）. For group A,the mean DCP surface strains under the load of 100,150,200 N was significantly higher than those in group B, C, D, and E （P〈0. 05 respectively） ,whilst the value of group E presented no significant difference compared to the group B,C,and D（P〉0.05 respectively

关 键 词：动力加压钢板 动力加压钢板应变 弯曲刚度 螺钉数量 三点折弯实验 

分 类 号：R683[医药卫生—骨科学]