【作者】 张桦；

【导师】 李家顺； 叶晓健； 袁文； 何海龙； 谢宁；

【作者基本信息】 第二军医大学 ， 外科学， 2009， 博士

【摘要】 目的研制一种新型微创化具有高度自稳性能的融合器,单独应用不附加椎弓根螺钉固定,并评价其生物力学稳定性。方法通过测量国人腰椎干燥标本和活体MRI获得与植入操作及cage设计有关的解剖数据,据此设计具有坚强的界面稳定性能和自稳性能的扩张式融合器。通过体外生物力学实验和腰椎椎间融合三维有限元模型分析评价比较扩张式融合器与圆柱状(Interfix)和箱形融合器(Telamon)的生物力学稳定性和自稳性能。同时分析融合器的应力分布情况。构建山羊侧后入路腰椎椎间融合模型以及研究单侧关节突关节切除对椎间融合影响情况。结果研制的扩张式融合器箱形体为主体,上下表面分布长倒齿,在植入椎间隙后,通过内芯将主体前部分向四周撑开扩张,同时将倒齿结构牢固地嵌入到骨性终板中。最大扩张角度为8°,设计的新型融合器型号分为:7、8、9、10mm规格。Expended组在前屈、后伸、侧屈和旋转各种状态下ROM值均小于Interfix组和Telamon组,扩张式融合器最大拔出力分别比Telamon和Interfix高98.1%和32.4%。有限元模型中扩张式融合器位移最小,平均0.085mm(左旋0.05mm～前屈0.11mm),其次是Interfix,Telamon位移最大。动物实验表明切除单侧关节突关节将显著影响椎间融合。结论新型扩张式融合器具有良好的界面稳定性能和自稳性能,在适应证下具有一定的临床应用价值。更多还原

【Abstract】 Objective To design a new type cage with enough initial stability, without pedicle screw fixation and evaluate the biomechanics stability. Methods The parameters related to new type cage design were obtained from anatomic measurements of lumbar specimen and human MRI scans. At the basis of the parameters, the new expended cage was designed. The biomechanics in vitro and finite element model were used to investigate the difference of biomechanical stability and self-stability three cages including: expended cage, threaded cage (Interfix) and impacted cage (Telamon). The goat latero-posterior lumbar intervertebral fusion model was established and compared with the results of groups interbody fusion with different excision rang of zygapophysial joints. Result The new type cage was designed nearly cuboid before expand during implantation procedure, then expanded , by impulsing the bolt in the posterior part of the cage, to increase the cage (intervertebral height and the contact area); teeth(height 1.5mm) on the contact surface. The expended angle was 8°, and the pattern had four kinds( 7,8,9,10mm) . Expended cage significantly decreased the ROM in flexion , extention ,lateral bending and rotation compared with Interfix and Telamon. The median pullout force of expended cage was 98.1% and 32.4% more than those of Telamon and Interfix respectively. The most dislodgement of cages were in rotation and the least were in flexion and extention. The median dislodgement of expended was least(0.085mm, 0.05mm in left rotation～0.11mm in flexion), compared to the other two type cages. The animal test showed zygapophysial joint play an important role in interbody fusion. Conclusion Theoretically the new type expended cage could be used alone without posterior pedicle screw fixation because of itself good biomechanical stability and self-stability.更多还原