Heat-induced changes in porcine annulus fibrosus biomechanics
Heat-induced changes in porcine annulus fibrosus biomechanics
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DOI：
10.1016/j.jbiomech.2003.07.002
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发表时间：
2004-02-01
影响因子：
2.4
通讯作者：
Lotz, JC
中科院分区：
文献类型：
--
作者：
Bass, EC;Wistrom, EV;Lotz, JC
椎间盘被认为是大量患者腰痛的根源。由于热疗法被认为对胶原组织有治疗作用，这项技术最近已被纳入几种微创背痛治疗。然而，患者选择标准和最佳剂量的精确定义受到治疗机制不确定性的阻碍。本研究的目的是量化一系列热暴露后纤维环生物力学的急性变化，并将这些结果与组织变性相关联。离体测试来自猪腰椎的完整纤维环（附接到相邻椎骨）。在37 ℃、50 ℃、60 ℃、65 ℃、70 ℃、75 ℃、80 ℃和85 ℃的水热处理前后测定生物力学行为、微观结构、变性吸热峰和变性焓（mDSC）。在85 ℃下处理后，还测量了切除的环状组织（从相邻椎骨中取出）的收缩率。治疗后观察到完整瓣环生物力学的显著差异，但其影响程度远小于切除瓣环和先前报告的其他组织。与此一致，在85 ℃下处理15分钟仅使完整组织发生最低程度的变性，而通过该方案使切除的组织完全变性。我们的数据表明，在原位约束所施加的联合结构显着延缓环的热变性。这些发现有助于解释临床结果，并为未来设计最佳给药方案提供依据。(C)2003爱思唯尔有限公司。保留所有权利。
The intervertebral disc is implicated as the source of low-back pain in a substantial number of patients. Because thermal therapy has been thought to have a therapeutic effect on collagenous tissues, this technique has recently been incorporated into several minimally invasive back pain treatments. However, patient selection criteria and precise definition of optimum dose are hindered by uncertainty of treatment mechanisms. The purpose of this study was to quantify acute changes in annulus fibrosus biomechanics after a range of thermal exposures, and to correlate these results with tissue denaturation. Intact annulus fibrosus (attached to adjacent vertebrae) from porcine lumbar spines was tested ex vivo. Biomechanical behavior, microstructure, peak of denaturation endotherm, and enthalpy of denaturation (mDSC) were determined before and after hydrothermal heat treatment at 37degreesC, 50degreesC, 60degreesC, 65degreesC, 70degreesC, 75degreesC, 80degreesC, and 85degreesC. Shrinkage of excised annular tissue (removed from adjacent vertebrae) was also measured after treatment at 85degreesC. Significant differences in intact annulus biomechanics were observed after treatment, but the effects were much smaller in magnitude than those observed in excised annulus and those reported previously for other tissues. Consistent with this, intact tissue was only minimally denatured by treatment at 85degreesC for 15 min, whereas excised tissue was completely denatured by this protocol. Our data suggest that in situ constraint imposed by the joint structure significantly retards annular thermal denaturation. These findings should aid the interpretation of clinical outcomes and provide a basis for the future design of optimum dosing regimens. (C) 2003 Elsevier Ltd. All rights reserved.