中国组织工程研究 ›› 2011, Vol. 15 ›› Issue (39): 7279-7283.doi: 10.3969/j.issn.1673-8225.2011.39.015

• 骨与关节生物力学 bone and joint biomechanics • 上一篇    下一篇

非融合棘突间固定器不同棘突间撑开高度对植入节段椎间盘压力分布的影响

刘长征1,姚庆强2,郑圣鼐2,唐  城2,徐  燕2   

  1. 1安徽省宿州市立医院骨科,安徽省宿州市 234000
    2 南京医科大学附属南京第一医院骨科,江苏省南京市  210006
  • 收稿日期:2011-06-08 修回日期:2011-07-25 出版日期:2011-09-24
  • 通讯作者: 郑圣鼐,博士,副主任医师,南京医科大学附属南京第一医院骨科,江苏省南京市 210006 superyqq@shou.com
  • 作者简介:刘长征,男,1963年生,安徽省宿州市人,汉族,1984年皖南医学院毕业,副主任医师,主要从事脊柱外科方面的研究。 liuchangzhengsz@sohu.com 并列第一作者:姚庆强★,男,1981年生,江苏省淮安市人,汉族,2008年南京医科大学毕业,硕士,主治医师,主要从事脊柱外科方面的研究。 superyqq@yahoo.com.cn

Effects of a new shape-memory alloy interspinous process device on the pressure distribution of implanted intervertebral disc segment

Liu Chang-zheng1, Yao Qing-qiang2, Zheng Sheng-nai2, Tang Cheng2, Xu Yan2   

  1. 1Department of Orthopaedics, Suzhou Municipal Hospital, Suzhou  234000, Anhui Province, China
    2Department of Orthopaedics, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing  210006, Jiangsu Province, China
  • Received:2011-06-08 Revised:2011-07-25 Online:2011-09-24
  • Contact: Zheng Sheng-nai, Doctor, Associate chief physician, Department of Orthopaedics, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing 210006, Jiangsu Province, China superyqq@shou.com
  • About author:Liu Chang-zheng, Associate chief physician, Department of Orthopaedics, Suzhou Municipal Hospital, Suzhou 234000, Anhui Province, China liuchangzhengsz@sohu.com Yao Qing-qiang★, Master, Attending physician, Department of Orthopaedics, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing 210006, Jiangsu Province, China superyqq@yahoo.com.cn Liu Chang-zheng and Yao Qing-qiang contributed equally to this study.

摘要:

背景:腰椎退变性疾病目前的非融合内固定特别是棘突间固定理论上可以保留有益活动,在缓解疼痛的同时预防邻近节段退变。
目的:测量棘突间不同的撑开程度情况下节段椎间盘负荷分担及应力分布情况。
方法:新鲜成人腰椎标本L2~5,采用电子万能实验机模拟腰椎前屈、中立、后伸运动负荷。实验分为7组:正常脊柱组,形状记忆合金棘突间固定器支撑高度10,12,14,16,18,20 mm组。
结果与结论:支撑高度为10 mm的形状记忆合金棘突间固定器对植入节段椎间盘的压力分布无显著性影响;支撑高度为12 mm的形状记忆合金棘突间固定器在过伸时可分担46%的椎间盘后纤维环负荷(P < 0.05);支撑高度为14 mm的形状记忆合金棘突间固定器可维持植入节段的轻度前屈,在过伸时可分担约47%的后环负荷(P < 0.05),但后伸时会增大前环的负荷,当支撑高度远大于植入节段中立位时的棘突间高度时,屈伸活动时,后环的负荷显著降低的同时,前环负荷可增大达400%。提示支撑高度等于或略大于中立位棘突间高度的非融合棘突间固定器可分担椎间盘负荷并使椎间盘应力更均匀分布;但支撑高度过大会明显增大前环的负荷,如果用于神经源性间歇性跛行患者的椎间孔撑开,可能会加快椎间盘的退变。

关键词: 腰椎退变, 棘突间固定, 生物力学, 动力性固定, 应力分布

Abstract:

BACKGROUND: The degeneration of the intervertebral disc and zygapophyseal joints (facet joint) is the main cause of degenerative lumbar stenosis with the clinical outcomes including chronic low back pain and neurogenic intermittent claudication. Dynamic stabilization devices, especially non-fusion interspinous process stabilization devices (IPD), are noteworthy in saving segmental movement, showing faster recovery and rehabilitation without increasing the degeneration of adjacent segments.
OBJECTIVE: To compare and quantify the disc pressure to understand the likelihood of accelerated disc degeneration in the implanted level to optimize the usage of the implant.
METHODS: Six cadaver lumbar specimens (L2–5) were loaded in flexion, neutral, and extension. A pressure measuring film measured the disc load during each of the three positions at each L3-4 disc level. The implant with different spacer height including 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm was placed at L3-L4 by turns, and the pressure measurements were repeated.
RESULTS AND CONCLUSION: The IPD with 10 mm spacer height could not significantly share the disc load. The 12 mm implant significant shared posterior annulus load only in extension. The 14 mm implant decreased the stress in posterior annulus and nucleus in extension and neutral but slightly increased the anterior annulus load. Though the 16 mm-20 mm implants decreased the posterior annulus’ stress significantly, the anterior annulus load was increased about 400% in aforementioned three positions. Different distraction degrees of interspinous process may lead to different disc load distribution, the implant would be not appropriate to those serious spinal stenosis because of the contradictions that though the over distraction can decrease the posterior annulus load and distract the intervertebral foramina, it will lead to an acceleration of disc degeneration by the excessive load increasing in anterior annulus.

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