新型人工髓核植入对腰椎稳定性影响的生物力学研究

Biomechanical research on the stability of lumbar spine with implantation of neotype artificial nucleus pulposus

目的:评价一种新型果胶/聚乙烯醇复合水凝胶人工髓核的生物力学性能,为其临床应用提供科学依据。方法:采用6具新鲜人体标本的L4/5脊柱功能单元进行生物力学实验,在轴向压缩、前屈后伸和左右侧弯等运动工况下,观察正常椎间盘、髓核摘除以及新型人工髓核CoPP植入三种状态下活动度(ROM)、中性区(NZ)的变化以及在中立位轴向加载下椎间隙高度变化。结果:髓核摘除后,L4/5椎间屈伸、旋转、侧弯的ROM和NZ较正常组显著增加(P<0.05),植入CoPP人工髓核后,L4/5椎间屈伸、侧弯、旋转的ROM和NZ与完整椎间盘无明显差异,除右侧弯外其他方向的ROM和NZ较髓核摘除组明显下降(P<0.05)。髓核摘除组在0和500N的负荷下椎间隙高度较相同情况下正常组平均下降1.08mm和1.77mm;CoPP人工髓核植入组较相同情况下髓核摘除组分别增加1.23mm和1.95mm。结论:新型果胶/聚乙烯醇复合水凝胶人工髓核植入椎间隙可维持腰椎节段正常的三维运动稳定性,恢复椎间隙高度,可望进入临床应用。

Objective： To evaluate the biomechanical properities of Pectin/ PVA composite （CoPP） hydrogel prosthetic nucleus,and provide scientific data for its clinical application. Methods： L4/5 functional spinal units from six fresh cadavers were used in the test. Under three different conditions （intact, nucleotomy and implantation of the prosthetic nucleus）, the range of motion, netrol zone and intervertebral disc height were analyzed in axial compression, flexion, extension, left and right bending positions. Results： For nucleotomy group, the ROM and NZ were significantly increased and the disc heights were reduced. Once CoPP prothesis was implanted, the stability and height of the intervertebral disc restored to that of the intact disc group. Conclusions： The new CoPP prostheses can restore the stability and height of the intervertebral disc after nucleotomy, and this new kind of hydrogel prosthetic nucleus is hopeful in clinical application.