The tensile behavior of demineralized bovine cortical bone
The tensile behavior of demineralized bovine cortical bone
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DOI：
10.1016/0021-9290(96)84546-5
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发表时间：
1996-11-01
影响因子：
2.4
通讯作者：
McMahon, TA
中科院分区：
文献类型：
--
作者：
Bowman, SM;Zeind, J;McMahon, TA
骨通常被建模为分散在有机胶原基质中的羟基磷灰石矿物晶体的两相复合物。然而，由于许多限制（例如，小样本量，应变测量技术差，快速脱矿质与酸）与化学去除羟基磷灰石的骨以前的机械测试，我们已经确定了新的，准确的数据，在这些复合材料模型中使用的脱矿质骨基质的材料特性。我们对六个肱骨干脱矿牛皮质骨的腰部标本进行了拉伸试验。用0.5 M EDTA二钠溶液（每日更换）对样本进行14天脱矿。原子吸收分光光度法用于跟踪脱矿过程，并确定我们的脱矿方案的有效性。在室温下，在位移控制下，以大约0.5%/s的应变率进行机械测试。我们在最终斜坡失效前进行了9次预处理循环，并使用非侵入性光学技术测量了标距位移。所得的应力-应变曲线与在其他胶原组织的机械测试中观察到的拉伸行为相似，表现出初始非线性“趾”区域，随后是线性区域和随后的失效，没有屈服的证据。我们发现平均模量、极限应力和极限应变为613 MPa（S.D. = 113 MPa）、61.5 MPa（S.D. = 13.1 MPa）和12.3%（S.D. = 0.5%）。我们的平均模量大约是目前复合骨分析中常用值的一半。这些数据也应该具有临床意义，因为愈合骨折骨的早期强度在很大程度上取决于胶原基质的材料特性。版权所有（C）1996爱思唯尔科学有限公司
Bone is frequently modeled as a two-phase composite of hydroxyapatite mineral crystals dispersed throughout an organic collagen matrix. However, because of the numerous limitations (e.g. small sample size, poor strain measuring techniques, rapid demineralization with acids) of previous mechanical tests of bone with its hydroxyapatite chemically removed, we have determined new, accurate data on the material properties of the demineralized bone matrix for use in these composite models. We performed tensile tests on waisted specimens of demineralized bovine cortical bone from six humeral diaphyses. Specimens were demineralized over 14 days with a 0.5 M disodium EDTA solution that was replaced daily. Atomic absorption spectrophotometry was used to track the demineralization process and to determine the effectiveness of our demineralization protocol. Mechanical tests were performed at room temperature under displacement control at an approximate strain rate of 0.5% per s. We imposed nine preconditioning cycles before a final ramp to failure, and measured gauge length displacements using a non-invasive optical technique. The resulting stress-strain curves were similar to the tensile behavior observed in mechanical tests of other collagenous tissues, exhibiting an initial non-linear 'toe' region, followed by a linear region and subsequent failure without evidence of yielding. We found an average modulus, ultimate stress, and ultimate strain of 613 MPa (S.D. = 113 MPa), 61.5 MPa (S.D. = 13.1 MPa), and 12.3% (S.D. = 0.5%), respectively. Our average modulus is approximately half the value frequently used in current composite bone analyses. These data should also have clinical relevance because the early strength of healing fractured bone depends largely on the material properties of the collagen matrix. Copyright (C) 1996 Elsevier Science Ltd.