THE DEPENDENCE OF INTERVERTEBRAL-DISK MECHANICAL-PROPERTIES ON PHYSIOLOGICAL CONDITIONS
THE DEPENDENCE OF INTERVERTEBRAL-DISK MECHANICAL-PROPERTIES ON PHYSIOLOGICAL CONDITIONS
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DOI：
10.1097/00007632-199008010-00004
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发表时间：
1990-08-01
期刊：
影响因子：
3
通讯作者：
SPENGLER, DM
中科院分区：
文献类型：
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作者：
KELLER, TS;HOLM, SH;SPENGLER, DM
对未成熟和成熟猪的腰椎进行体内蠕变恢复和椎间盘压力测量。使用定制材料试验装置进行蠕变-恢复测量，该装置设计用于向麻醉动物的脊柱施加静态或动态载荷。进行了一系列三个单独的实验，以评估以下因素的影响：（I）动物死亡，（II）椎间盘环的分级损伤，和（III）呼吸力学对猪L1-L3脊椎单元（VU）生化反应的影响。在实验I和II中，蠕变速率，模量和粘度参数计算使用三参数固体流变学分析的位移-时间响应期间记录的应用程序的300 N的负载。在实验III中，在卸载，静态加载和固定猪VU的呼吸量和频率的变化对椎间盘压力的影响进行了评估。我们的研究结果表明，成年VU往往是僵硬，变形或蠕变更慢，并有一个显着较高的粘度比VU的未成年猪。实验I的结果表明，VU的生物力学响应显着改变的动物的死亡; VU的活动物（青少年或成熟）是更顺应性和变形的速度比VU的同一动物死亡后。椎间盘损伤产生的刚度、粘度和蠕变率变化与老化相似，根据本研究中产生的分级损伤，似乎瓣环中的小缺陷与去除大部分瓣环材料一样有害。实验III的结果表明，呼吸在猪VU的正常、体内机械和营养行为中起着重要作用。总之，这些结果表明，在没有正常的生理条件下，可能无法可靠地预测腰椎的机械反应，并建议应建立生物组织的测试，处理和储存标准。
In vivo creep-recovery and disc pressure measurements were performed on the lumbar spine of immature and mature swine. The creep-recovery measurements were performed using a custom materials testing apparatus designed to apply static or dynamic loads to the spine of anesthetized animals. A series of three separate experiments were performed to assess the effects of: (I) animal death, (II) graded injury to the disc anulus, and (III) respiratory mechanics on the biochemical response of the porcine L1-L3 vertebral unit (VU). In Experiments I and II, creep rate, modulus, and viscosity parameters were computed using a three-parameter solid rheological analysis of the displacement-time response recorded during the application of a 300-N load. In Experiment III, the effects of respiratory volume and frequency changes on disc pressure were assessed in the unloaded, statically loaded, and immobilized porcine VU. Our results indicated that the adult VU tended to be stiffer, deform or creep more slowly, and has a significantly higher viscosity than the VU of immature pigs. The results of Experiment I demonstrated that the biomechanical response for the VU was significantly altered by the death of the animal; the VU of the living animal (adolescent or mature) was more compliant and deformed at a faster rate than the VU of the same animal after death. Disc injury produced changes in stiffness, viscosity, and creep rate analogous to that of aging, and on the basis of the graded injuries created in this study, it appears that a small defect in the annulus is just as deleterious as removing a large section of anular material. The results of Experiment III indicated that respiration plays an important role in the normal, in vivo mechanical and nutritional behavior of the porcine VU. Altogether, these results demonstrate that, in the absence of normal physiologic conditions, one may not be able to reliably predict the mechanical response of the lumbar spine, and suggest that standards for the testing, handling, and storage of biologic tissue should be established.