国人解剖型多孔镁合金腰椎融合器的生物学特性及生物力学研究

Lumbar interbody fusion cage had been widely used as the conventional implants for lumbar intervertebral fusion. However, Polyetheretherketones and carbon fiber reinforced ploymers are mostly used as materials for cage and therefore, there will be stress shielding effect. The characters of new porous magnesium alloys are mostly the same as human bone. it had been proved that porous Mg alloys is able to become the ideal material for making lumbar cage. Meanwhile, during the past 2 projects on spinal anatomy research, we had proved there is difference between Chinese and European lumbar anatomic characteristics. Most cages are not suitable for Chinese anatomic spinal data that most interbody cages were designed according to European and cannot fit the endplate well. Our study is designed to implant such a new porous magnesium alloys cage in goat model, then cage degradation and interbody fusion will be evaluated through radiology and histology. Simutaneously, various tests will also be performed to explore lumbar biomechanical changes accompanied with cage degradation. And to describe the anatomical characteristics of lumbar endplate through reverse engineering softwares and create a fitting surface of endplate. We will utlize Mg alloy to make porous lumbar interbody cage, which fits Chinese anatomic characteristics. Biomechanical evaluations will also be used to compare the results between cages made of PEEK and Mg-Mn alloy respectively. The present study aims to provide theoretical basis for making new lumbar interbody cage on biomaterial and biomechanics science.

椎间融合器是腰椎融合术中最常使用的植入物之一，目前以不可吸收的聚醚醚酮及碳纤维材料为主，存在”应力遮挡“等较多问题与不足。新型可吸收多孔镁合金生物学特性更接近人体骨骼，在前期多方面的研究中已初步证实该材料有望成为腰椎融合器制备材料的理想选择。另一方面，在既往两项脊柱解剖研究面上项目中，我们多次证实国人腰椎解剖学特征与欧美人种存在较大差异，而目前腰椎融合器大部分基于欧美人群解剖参数设计，不完全适于国人个体且形态无法与接触终板完全契合。本研究拟将多孔镁合金融合器植入山羊腰椎融合模型体内，通过影像与组织学方法观察其降解及骨融合过程，分析生物学特性；通过逆向工程软件拟合符合国人腰椎终板曲面的融合器形态，设计出一种契合国人终板曲率、以镁合金为制作材料的新型可吸收腰椎间融合器，并分析其力学支撑强度及生物力学优势，为国人解剖型多孔镁合金腰椎融合器的最终临床应用提供生物材料学与生物力学的理论基础。

椎间融合器是腰椎融合术中最常使用的植入物之一，目前以不可吸收的聚醚醚酮及碳纤维材料为主，存在”应力遮挡“等较多问题与不足。新型可吸收多孔镁合金生物学特性更接近人体骨骼，在前期多方面的研究中已初步证实该材料有望成为腰椎融合器制备材料的理想选择。另一方面，在既往两项脊柱解剖研究面上项目中，我们多次证实国人腰椎解剖学特征与欧美人种存在较大差异，而目前腰椎融合器大部分基于欧美人群解剖参数设计，不完全适于国人个体且形态无法与接触终板完全契合。.本研究将多孔镁合金融合器植入山羊腰椎融合模型体内，通过影像与组织学方法观察其降解及骨融合过程，发现其由于制作工艺的限制，镁材料的多孔结构难以精 确控制，故能同时实现合理降解速率、足够力学强度、优秀成骨诱导作用的镁融合器的理想多孔结构尚未明确；但是，本课题组主要通过逆向工程软件拟合符合国人腰椎终板曲面的融合器形态，并成功设计出一种契合国人终板曲率、以镁合金为制作材料的新型可吸收腰椎间融合器，发现其力学支撑强度及生物力学具有优势，为国人解剖型多孔镁合金腰椎融合器的最终临床应用提供生物材料学与生物力学的理论基础。