Coflex和X-STOP治疗腰椎管狭窄的生物力学性能

发布时间：2018-05-08 18:39

本文选题：棘突间撑开器 + 腰椎管狭窄症　；参考：《医用生物力学》2015年04期

【摘要】：目的分析棘突间撑开器Coflex和X-STOP在治疗腰椎管狭窄中的不同生物力学特性,为棘突间植入物的设计改进提供参考。方法依据1名正常志愿者中立位下螺旋CT扫描资料构建L2~5健康腰椎有限元模型、L4/5椎间盘轻度退变有限元模型、棘突撑开器X-STOP和Coflex的动态固定模型,并对4组模型分别模拟前屈、后伸、侧弯和轴向旋转,验证和对比分析活动度(range of motion,ROM)的变化和应力在棘突和撑开器上的分布。结果与退变模型相比,Coflex和X-STOP有效限制退变节段后伸ROM-48.12%和-75.35%,Coflex还能限制前屈ROM-59.58%,侧弯和扭转ROM不受限制。Coflex和X-STOP减少椎间盘后伸时应力达-58.03%和-80.75%,Coflex在前屈时应力减少-52.84%。侧弯和扭转的ROM基本不受影响。Coflex最大应力发生在前屈时U型弯处,X-STOP最大应力出现在扭转时左翼螺钉连接处。Coflex与腰椎接触最大应力发生在扭转时,为31.38 MPa。X-STOP与腰椎接触最大应力发生在侧弯时,为46.86 MPa。结论 Coflex和X-STOP是治疗腰椎管狭窄的有效方法,均可以显著降低后伸ROM和椎间盘压力,对相邻节段无明显影响。
[Abstract]:Objective to analyze the different biomechanical characteristics of spinous process distractor Coflex and X-STOP in the treatment of lumbar spinal canal stenosis and to provide reference for the design improvement of spinous process implants. Methods according to the spiral CT scanning data of a normal volunteer in neutral position, the L2B5 healthy lumbar spine model was constructed with the finite element model of mild degeneration of L4 / 5 disc, the dynamic fixation model of spinous process distractor X-STOP and Coflex, and the four groups of models were simulated by anterior flexion. Extension, lateral bending and axial rotation are used to verify and compare the variation of range of motion ROM and the distribution of stress on spinous process and diffuser. Results compared with the degenerative model, Coflex and X-STOP can effectively limit the extension of retrograde segments by ROM-48.12% and -75.35Coflex can also limit the flexion of ROM-59.58. The lateral bending and torsion of ROM can not be restricted. Coflex and X-STOP can reduce the stress of intervertebral disc extension by -58.03% and -80.75Coflex by -52.84%. The ROM of lateral bending and torsion is basically unaffected. Coflex maximum stress occurs at the U-shaped bend during forward flexion and the maximum stress of X-STOP occurs at the junction of left flank screw during torsion. Coflex is in contact with the lumbar vertebrae during torsion. The maximum contact stress of 31.38 MPa.X-STOP with lumbar vertebrae was 46.86 MPA at lateral bending. Conclusion Coflex and X-STOP are effective methods in the treatment of lumbar spinal canal stenosis. Both of them can significantly reduce ROM and disc pressure, but have no significant effect on adjacent segments.
【作者单位】：上海理工大学教育部微创医疗器械工程研究中心;
【基金】：上海市专业学位研究生实践基地建设项目(1014308301)
【分类号】：R681.5;R318.01

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