DRFS系统的体外生物力学测试  

Distraction Reduction Fixation System in Vitro

作　　者：李禾[1] 高春华[1] 姜川[1] 张新宇[1] 白晓东[1] 叶启彬[2] 汪爱媛[3] 

机构地区：[1]武警总医院骨科,北京市100039 [2]北京协和医院骨科 [3]解放军总医院骨科研究所

出　　处：《中国骨与关节损伤杂志》2009年第6期509-511,共3页Chinese Journal of Bone and Joint Injury

基　　金：武警部队科研资助项目(WZ200502)

摘　　要：目的测试DRFS系统固定后脊柱标本的刚度及其椎弓根钉的拔出力,评估DRFS系统临床应用的可靠性。方法选择猪脊柱标本12具,测试其前屈、后伸、侧屈及旋转时的刚度;制成失稳标本后,重复各项运动刚度测试;用DRFS固定失稳标本后,再重复各项运动刚度测试。选择双节段腰椎标本12对,分别拧入DRFS系统椎弓根钉(固定钉、提拉钉)后,进行拔出测试。结果在猪脊柱标本前屈、后伸、侧屈及旋转活动的刚度测试中,与完整脊柱的刚度相比较,失稳脊柱各项运动的刚度均明显减小(P<0.05);DRFS系统内固定后,脊柱各项运动的刚度均明显高于失稳脊柱(P<0.05),固定钉的拔出力明显大于提拉钉(P<0.01)。结论DRFS系统内固定术后脊柱标本的刚度明显高于失稳标本,其椎弓根钉可提供足够的提拉力。Objective To test the post-operative stiffness of the spine instrumented with the distraction reduction fixation system （DRFS） and the holding power of its laminar. Methods Twelve porcine spines （12 segnments each） were prepared for the biomechanieal test. The spinal stiffness during forward-bending,backward-bending,lateral-bending and axial rotation were determined; then the specimen of spine as unstable status was established by destroying the intervertebral discs and the facet joints,followed by repeating the stiffness test; and DRFS were applied for internal fixation to the unstable spine and stiffness tests were repeated again.The data collected from these 3 steps were analyzed to study the stiffness of DRFS-instrumented spine by serf-control comparison. Twelve mono-segmcnt vertebrae specimens （12 fixation screw and 12 pull screw ） with DRFS pedical screw were selected to perform pull-out test to study the holding power of DRFS in vitro. Results The stiffness in unstable porcine spine was significantly lower than those either in intaetporcine spine or in the DRFS- instrumented porcine one （P〈0.05）, but it was similar between the two latter during forward-bending, lateral-bending and axial rotation except that it was higher during backward-bending in the DRFS- instrumented porcine （P〈0.05）. The holding power of fixation screw was larger than that of pull screw （P〈0.01）. Conclusion Compared with unstabled porcine spine, the stiffness in DRFS-instrumented porcine is markedly improved than in unstable porcine spine , except backward-bending, which is comparable with the group of intactporcine spine. DRFS can also provide sufficient holding power in vitro porcine spine.

关 键 词：脊柱 内固定 刚度 拔出力 

分 类 号：R684.705[医药卫生—骨科学] R687.32[医药卫生—外科学]