螺钉数量对钢板螺钉内固定结构载荷的生物力学影响  

Effects of screw number in dynamic compression plates on the stability of plate and screw structure

作　　者：张魁忠[1] 吴柄华[1] 徐聪[1] 邓高荣[1] 凌强[1] 李太强[1] 

机构地区：[1]南昌大学第四附属医院骨科,江西省南昌市330003

出　　处：《中国组织工程研究与临床康复》2009年第43期8454-8457,共4页Journal of Clinical Rehabilitative Tissue Engineering Research

摘　　要：背景:根据目前生物力学内固定要求的提出,课题根据临床中部分骨折区域或者多段骨折处无法固定螺钉的实际情况,探讨部分钢板的螺钉孔不固定螺钉后对钢板螺钉内固定结构的稳定性。目的:观察螺钉数量对钢板螺钉结构稳定性的影响。设计、时间及地点:随机分组设计,对比观察,于2007-03/2008-05在南昌大学医学院和南昌航空航天大学完成。材料:24个新鲜尸体股骨标本,由南昌大学医学院解剖实验室提供。钛合金动力加压钢板24块,为康辉医疗器械有限公司产品。方法:每个股骨模拟横断骨折,一块12孔的动力加压钢板对称性固定,每块钢板贴3个(分别编号ε1,ε2,ε3)应变计与钢板长轴平行。24个股骨骨折标本随机分为4组,每组6个标本。按下列分组连续进行测试:A组:1-2-6(1-2-6表示螺钉位置);B组:1-2-3-6;C组:1-2-3-4-6;D组:1-2-3-4-5-6。主要观察指标:在材料实验机上分别进行平行矢状面方向的三点折弯实验,观察应力为200,400N时各组钢板的应变、挠度;随后进行扭转实验,观测股骨的扭转角度为1.428°,2.142°时各组钢板的应变变化。结果:①在三点折弯实验中,A组中骨折端的平均应变最大,D组中骨折端的平均应变最小。A组和C组,A组和D组,B组和D组之间钢板的平均应变差异均有显著性意义(P<0.05),其余各组之间差异均无显著性意义(P>0.05)。在200N和400N的压应力作用下,A、B、C、D各组间挠度变化值两两相比,差异均有显著性意义(P<0.05)。与200N压应力作用相比,400N压应力作用挠度变化更大(P<0.05)。②扭转角度在2.142°内,各组样本在钢板中央应变差异均有显著性意义(P<0.05)。其中B组钢板应变最低,D组钢板应变最高,在钢板中央的应变与扭转角度呈正相关。结论:螺钉数量对钢板螺钉内固定结构系统的稳定性有显著性影响,较少固定螺钉的数量,增加了钢板螺钉内固定结构的弹性形变能力。BACKGROUND： According to requirement of biomechanical fixation, this paper discussed the stability of plate and screw structure with some holes in the absence of screws as some fracture or multiple segmental fracture cannot be fixed by screws. OBJECTIVE： To investigate the effects of the number of screw in the dynamic compression plates on the stability of plate and screw structure in vitro. DESIGN, TIME AND SETTING： Randomized grouping and comparative observation were performed at the Nanchang University Medical School and Nanchang Hangkong University from March 2007 to May 2008. MATERIALS： A total of 24 fresh cadaveric femora were provided by the Anatomy Laboratory of Nanchang University Medical School. Twenty-four Titanium alloy compression plates were purchased from Kanghui Medical Innovation, Co., Ltd. METHODS： Every femur was cut transversely in the median to simulate transverse fracture and fixed by a 12-hole dynamic compression plate attached by screws. Three sensor gauges （No. ε1, ε2, ε3） were installed on each plate parallelly. Twenty four fresh femora were randomly divided into 4 groups with 6 specimens in each group. Screw number of the four groups were： A： 1-2-6 （screw location）; B： 1-2-3-6; C： 1-2-3-4-6 D： 1-2-3-4-5-6. MAIN OUTCOME MEASURES： Each group was tested by three point bending. The strain and deflection of each group at 200 and 400 N stress were observed. The torsion test was performed to detect the strain changes of the plates at 1.428~ and 2.142~ torsional angle. RESULTS： In three point bending, the strain in the fracture model was highest in group A and lowest in group D. There were significant differences in the strain between group A and C, A and D, and B and D （P 〈 0.05）. There was no significant difference in the strain between A and B, B and C, C and D （P 〉 0.05）. Under 200 and 400 N stress, the deflection between any two groups displayed significant differences （P 〈 0.05）. Compared with 200 N stress, the deflection changes were o

关 键 词：动力加压钢板 螺钉数量 稳定性 三点折弯实验 扭转实验 

分 类 号：R318[医药卫生—生物医学工程]