On the Extent and Nature of Nucleus-Annulus Integration
On the Extent and Nature of Nucleus-Annulus Integration
复制标题
论核-环整合的程度和性质
DOI：
10.1097/brs.0b013e3182637f04
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发表时间：
2012
期刊：
影响因子：
3
通讯作者：
N. Broom
中科院分区：
文献类型：
--
作者：
K. Wade;P. Robertson;N. Broom
研究设计.核-环整合的机械和微观结构评估。Objective.探讨核与内环之间是否存在结构整合。背景数据总结。细胞核通常被视为一个流体静力学功能的实体，它在很大程度上与周围环境分离。核和环之间的边界被认为是难以界定的。方法.从绵羊腰椎间盘的中央区域切下10毫米厚的矢状板。环核过渡区被隔离，所得样品经受横向拉伸载荷直至失效。类似的样品被拉伸到约4至5倍的原始分离，然后进行显微结构检查，以研究整个内环核区域的结构整合。结果瓣环-核边界可承受5.7 N（范围：2-11.5 N）的平均载荷。拉伸载荷导致髓核的纤维结构在横向拉伸方向上被拉成近似对齐，并伴随着内环层的相关反向向内拉。在高倍镜下，可以看到水平排列的核纤维分支并与内环结构融合。结论核包含一个卷曲但高度结构化的不同长度的纤维网络，这些纤维似乎与内环整合，并赋予了可以机械证明的显著程度的横向互连。这一新的实验证据，以及先前证明核-终板连接的研究，清楚地表明核不能被认为是椎间盘中的一个独立实体。我们建议，这种结构的整合提供了一种形式的拴系的流动性，支持不同的运动节段的主要强度要求的生理功能的核。
Study Design. Mechanical and microstructural assessment of nucleus-annulus integration. Objective. To investigate the existence of structural integration between the nucleus and the inner annulus. Summary of Background Data. The nucleus is often viewed as a hydrostatically functioning entity that is largely separate from its surroundings. The boundary between nucleus and annulus is acknowledged as difficult to define. Methods. Ten-millimeter-thick sagittal slabs were cut from the central region of ovine lumbar discs. The annulus-nucleus transition region was isolated and the resulting samples subjected to transverse tensile loading up to failure. Similar samples were stretched to about 4 to 5 times their original separation and then subjected to microstructural examination to investigate structural integration across the inner annulus-nucleus region. Results. The annulus-nucleus boundary could support an average load of 5.7 N (range, 2–11.5 N). Tensile loading causes the fibrous structure of the nucleus to be drawn into an approximate alignment in the transverse stretch direction with an associated reverse inpulling of the inner annular layers. At high magnification, the horizontally aligned nucleus fibers can be seen to branch and blend with the inner annular structure. Conclusion. The nucleus contains a convoluted but highly structured network of fibers of varying length, which appear to integrate with the inner annulus and confer a significant degree of transverse interconnectivity that can be demonstrated mechanically. This new experimental evidence, together with that from a previous study demonstrating nucleus-endplate connectivity, makes it clear that the nucleus cannot be considered as a separate entity in the disc. We propose that this structural integration provides the nucleus with a form of tethered mobility that supports physiological functions distinct from the primary strength requirements of the motion segment.