【作者】 吕宏琳；

【导师】 周跃；

【作者基本信息】 第三军医大学 ， 外科学， 2008， 博士

【摘要】 目的:评估国人应用微创经骶骨前入路腰骶椎融合内固定系统的可行性,初步设计适合国人的微创经骶骨前入路腰骶椎融合内固定系统及手术方式,并研究内固定系统在材料力学和机械性能等方面的特点,同时评估其对腰骶椎运动节段稳定性的生物力学影响,探讨其在保持腰骶椎稳定中的作用和意义,从而对自主设计的适合国人的微创经骶骨前入路腰骶椎融合内固定系统进行评估,为进一步加以改进和临床应用提供实验基础。方法:①通过对我国正常男女两组实验对象腰骶椎影像解剖数据的统计学测量和分析,参考国外相关手术操作,对国人应用微创经骶骨前入路腰骶椎融合内固定系统的可行性进行评估。②结合实验中分析所得的我国正常男女腰骶椎影像解剖数据和特点,按照人性化设计的基本要求和人机工程学的设计规范,设计适合国人的微创经骶骨前入路腰骶椎融合内固定系统及手术方式。③通过有限元分析,探讨自行设计的微创经骶骨前入路腰骶椎融合内固定系统在材料力学和机械性能方面的特点。④结合实验动物腰骶椎运动节段进行生物力学测试,在运动节段的不同状态下,检测应用微创经骶骨前入路腰骶椎融合内固定系统所引起的生物力学变化,评估其对腰骶椎运动节段稳定性的影响,探讨其在保持腰骶椎稳定中的作用和意义。结果:①腰骶椎影像解剖统计学数据显示,具备满足微创经骶骨前入路腰骶椎融合内固定系统最基本要求的手术路径,但手术切口和骶骨手术进入点的位置均与国外手术方式不同。②初步设计出适合国人的微创经骶骨前入路腰骶椎融合内固定系统及手术方式,其理论上具有合理优化的结构,可以完成椎间盘切除、椎间隙处理、椎间隙撑开、椎间融合和体内固定等手术操作,最大限度的减少对手术入路组织、椎旁软组织和脊柱结构的损伤和破坏。③对设计的适合国人的微创经骶骨前入路腰骶椎融合内固定系统的有限元分析显示,在人体腰骶椎生理和极限两种负荷状态下,以钛合金或不锈钢合金为制造材料,内固定系统均达到了强度设计要求,而且机械性能特点基本相同。④腰骶椎运动节段应用设计的微创经骶骨前入路腰骶椎融合内固定系统后,轴向抗压刚度明显提高,并且在后柱结构稳定的情况下,其在前屈、后伸、左右侧屈及旋转六个方向的运动范围显著缩小;在单侧峡部断裂的情况下,其向健侧旋转的运动范围有所扩大,但仍显著小于正常运动范围;在双侧峡部断裂的情况下,其旋转运动的范围进一步增大,接近正常运动范围,但联合后路椎弓根螺钉固定后,范围即又显著缩小。全文结论:在我国正常男女腰骶椎的解剖结构条件下,应用微创经骶骨前入路腰骶椎融合内固定系统是可行的,但其具体实施方式与国外不同,有自己的特点。自行设计的微创经骶骨前入路腰骶椎融合内固定系统及手术方式,理论上达到了人性化设计的基本要求和人机工程学的设计规范,即适合国人、结构优化、能够完成基本腰骶椎手术操作和最大限度的降低手术创伤。不论是以钛合金还是不锈钢合金为制造材料,内固定系统的设计均满足在人体腰骶椎生理和极限状态下的强度要求,并且机械性能特点基本相同。内固定系统能够显著提高腰骶椎的轴向抗压能力。在腰骶椎后柱结构稳定的情况下,内固定系统能够明显限制腰骶椎运动节段的各方向运动,显著增强腰骶椎稳定性;在后柱结构相对不稳的情况下,其限制运动节段旋转运动的作用有所减弱,但仍能明显增强腰骶椎稳定性;在后柱结构绝对不稳的情况下,其限制运动节段旋转运动的作用进一步减弱,不能显著增强腰骶椎在旋转运动方向上的稳定性,需要联合后路椎弓根螺钉固定加以辅助。综上所述,自行设计的适合国人的微创经骶骨前入路腰骶椎融合内固定系统,达到了结构、材料、机械性能、生物力学等多方面的设计要求,是一种合理、可行、优化的新型微创腰骶椎前路轴向融合内固定手术操作系统。同时,我们可以通过其它相关研究和临床实验性应用,对此内固定系统进行进一步的改进和完善,以求最终顺利的应用于临床。更多还原

【Abstract】 Objective:To analyze the feasibility of a minimally invasive lumbosacral fusion and fixation device via presacral approach used to the native, and to initially design the device fit to the native and its modus operandi, research its characteristics in the mechanics of materials and mechanical function, and reveal its influence and significance in the stabilization of the lumbosacral vertebrae. This study is focus on the design and evaluation of the device, which will offer basic experimental information for its further development and clinical application.Method:①To analyze the feasibility of the minimally invasive device used to the native by statistically measuring and observing the related anatomical data of lumbosacral vertebrae in the plain films of normal male and female experimental groups, and conferring to the related foreign surgery.②To design the minimally invasive device fit to the native and its modus operandi at the base of anatomical data and feature of the native lumbosacral vertebrae, according to the basic requirement of humanized design and the design code in Ergonomics.③To research its characteristics in the mechanics of materials and mechanical function by the finite element analysis.④To reveal its influence and significance in the stabilization of the lumbosacral vertebrae through examining the biomechanical changes in the lumbosacral functional unit of experimental animal under the different conditions.Result:①It could be discovered in the statistical data of lumbosacral vertebral radiology anatomy in the experimental objects, which a surgery approach corridor was existent, consisted with the essential requirement of the device. But it was different with the foreign in the points of entry on the skin and sacrum.②It has been initially designed that the minimally-invasive presacral lumbosacral fusion and fixation device. The reasonable optimized structure belonged to the device in theory, which could achieve the basic operative procedures successfully in L5–S1 intervertebral space, such as the discectomy, interbody distraction, interbody fusion and fixation, and so on. At the same time, the device could preserve the integrity of the paravertebral tissue, surgical approach tissue and natural spinal structure with minimally invasive injury, such as the muscles, ligaments and vertebral plates etc.③The characteristics of the designed device have been displayed by the finite element analysis that were in the mechanics of materials and mechanical function. Whether made of stainless steel or titanium alloy, the device always met the designing requirement of strength, under the physiological and extreme load states of the lumbosacral vertebrae. And the characteristics in mechanical function were basically identical.④The axial compressive stiffness of the lumbosacral functional unit was obviously increased by using the designed device to the experimental animal model. The ROM in flexion was marked reduced from the normal when the spinal posterior column was stable, and the similar reductions in ROM were observed in extension, right LB, left LB, CK torsion and CCK torsion. When the spinal posterior column had the unilateral isthmectomy, the rage of torsional motion in the rotation to the healty side was increased, but it was still visibly lower than the normal’s. With the biolateral isthmectomy in the spinal posterior column, there was an evident increase in the rage of torsional motion in the both rotations, and it was close to the normal level. While fixed with the pedicle screws, the functional unit immediately had a more marked reduction in the ROM than before.Conclusion: It is feasible to the normal native that the minimally invasive lumbosacral fusion and fixation device is used via presacral approach. This is determined by their anatomy construction of the lumbosacral vertebra. The actual operating mode is different with the foreign, and has its own feature. The initially designed device combines four main characteristics, including native application, optimized structure, achieving the basic lumbosacral operative procedures successfully and minimally-invasive injury. It has been attained by the device in theory that the basic requirement of humanized design and the design code in Ergonomics. Whether the making material is stainless steel or titanium alloy, the design of the device always meets the requirements of strength under the physiological and extreme load states of the lumbosacral vertebrae. And basically identical characteristics are displayed in mechanical function. The new designed device has a kind of obvious function to increase the axial compressive stiffness of the lumbosacral functional unit. When the spinal posterior column is stable, the motion of lumbosacral vertebrae is so markedly limited by using the device to strengthen of the unit stability. This function is weakened, especially the limitation in the torsional motion, as the spinal posterior column changes to be partly stable. While it is still firm enough to strengthen the stability visibly. But when the absolute instability occurs in the spinal posterior column, its function of the limitation in the torsional motion is more weakened, even closed to normal level. Then by the device, it has not been strengthened evidently in the torsional rotation which the stability of the unit. The device is necessarily with the auxiliary fixation by the pedicle screws. In summary, various design requests, such as the structure, the material, the mechanical function, biological mechanics, and so on, have been attained by the designed minimally invasive lumbosacral fusion and fixation device via presacral approach fit to the native, which is one kind reasonable, feasible and optimized minimally invasive operative system for the anterior axial lumbosacral fusion and fixation. At the same time, we may through other research correlated and the experimental clinical practice to further improve and consummate it, which is finally applied in the clinical treatment smoothly.更多还原