中上胸椎椎弓根-肋骨复合体应用不同截面积螺钉的力学特点  

Mechanical property of different cross-sectional area screws in middle and upper horacic vertebral pedicle-rib complex

作　　者：辛大奇[1] 霍洪军[1] 杨学军[1] 邢文华[1] 赵岩[1] 付裕[1] 祝勇[1] 李峰[1] 

机构地区：[1]内蒙古医科大学第二附属医院脊柱外科,内蒙古自治区呼和浩特市010030

出　　处：《中国组织工程研究》2014年第9期1356-1361,共6页Chinese Journal of Tissue Engineering Research

基　　金：内蒙古自治区科技厅基金项目(20090501)~~

摘　　要：背景:由于椎弓根毗邻结构的重要性,一旦置钉偏差损伤毗邻结构后果极为严重,虽然胸椎椎弓根-肋骨复合体置入螺钉的安全性明显大于椎弓根螺钉,但关于椎弓根-肋骨复合体应用不同截面积的螺钉的力学研究尚少有人涉及。目的:分析中上胸椎椎弓根-肋骨复合体应用不同截面积螺钉的力学特征。方法:取5具新鲜成人胸椎T1-T10标本及相连的一段肋骨(长50-60 mm),以双功能骨密度测试仪测量椎体骨密度,排除骨质疏松椎体,同时行胸椎CT扫描。按照CT测量结果置入直径分别为5.5,6.0和6.5 mm的椎弓根螺钉,进行CT扫描证实螺钉的位置,生物力学测试机上测量每颗螺钉的最大拔出力。结果与结论:38个骨密度正常的标本共分别置入25枚5.5 mm、25枚6.0 mm和26枚6.5 mm螺钉,由于螺钉破坏椎弓根-肋骨复合体和螺钉穿破椎体,共得出68枚螺钉最大拔出力结果,三者的最大轴向拔出力分别为(812.36±147.22)N,(868.64±160.48)N,(946.48±157.58)N,其中6.5 mm与5.5 mm螺钉的最大轴向拔出力的差异有显著性意义(P<0.05)。提示中上胸椎椎弓根-肋骨复合体中应用直径5.5 mm以上的椎弓根螺钉,可获得坚强的内固定,可满足临床内固定需要。BACKGROUND： Due to the importance of pedicle adjacent structures, once the screw replacement appears a deviation, adjacent structures may be damaged, leading to extremely serious consequences. Although the security of screw placement in thoracic vertebral pedicle-rib complex is significantly greater than that of pedicle screws, the mechanics of the pedicle-rib complex at different cross-sectional areas of the screw are rarely reported. OBJECTIVE： To observe mechanical property of different cress-sectional area screws in the middle and upper thoracic vertebral pedicle-rib complex. METHODS： Five specimens of adult cadaveric thoracic spine （T1-TI0） and adjacent rib segment （50-60 mm long） were used. The bone density of specimens was measured using difunctional bone density testing machine, and osteoporotic vertebral body was excluded. The position of the screws was detected with CT images. The maximal withdrawal force of the pedicle screw was measured with biomechanical force test machine. RESULTS AND CONCLUSION： Thirty-eight specimens at normal bone density were implanted with 25 screws （5.5 mm）, 25 screws （6.0 mm） and 26 screws （6.5 mm）. Because the pedicle screws destroyed the pedicle-rib complex and perforated the vertebral body, we finally obtained the withdrawal force of 68 screws. The axial withdrawal force of pedicle screws at different diameters was （812.36±147.22） N, （868.64±160.48） N and （946.48±157.58） N, respectively. There were significant differences between the 5.5 mm screws and the 6.5 mm screws （P 〈 0.05）. Experimental findings indicate that. the pedicle screws （diameter 〉 5.5 mm） are suitable in the middle and upper thoracic vertebral pedicle-rib complex due to strong internal fixation and clinical requirement.

关 键 词：植入物 脊柱植入物 脊柱 中上胸椎 椎弓根-肋骨复合体 椎弓根 椎弓根螺钉 直径 内固定 生物力学 

分 类 号：R318[医药卫生—生物医学工程]