脱钙模拟椎体骨质疏松体外模型的建立

Development of an in vitro model to mimic vertebral osteoporosis by decalcification

目的利用乙二胺四乙酸二钠盐(EDTA-Na2)体外脱钙模拟椎体骨质疏松,测量猪3联椎体骨密度和生物力学的特性,探讨一种短期制造骨质疏松性椎体压缩骨折模型的方法。方法取49个新鲜猪胸腰椎3联体,随机分成7组,记为A.B.C.D.E.F.G每组7个标本,然后把B.C.D.E.F.G标本侵入0.4916 mmol/L的EDTA-Na2脱钙液体中,分别在0、5、7、9、11、13、15天分别行A.B.C.D.E.F.G骨密度、生物力学、Mcro-ct检查及每组取一个标本大体剖开。结果随着脱钙时间的延长,大体观察可见各组标本骨小梁逐渐变细、间隙增宽,骨密度检测结果显示逐渐减低的趋势,并且各组脱钙前后骨密度变化均有明显的差异性(P=0.0000)。随着脱钙时间的延长椎体压缩强度逐渐降低,脱钙前后相比压缩强度均有显著性差异(P=0.0000)。Micro-CT检测脱钙13天椎体及棘突骨矿物质密度、组织骨密度、骨体积分数、结构模型指数、欧拉数、骨小梁连结密度均有明显的变化(P≤0.02)。结论采用0.4916 mmol/L EDTA-Na2脱钙11～13天可模拟中、重度骨质疏松性椎体压缩骨折,是一种快速、可行、重复性高的方法。

Objective To develop an in vitro model to mimic osteoporosis using ethylenediaminetetraacetic acid disodium salt （EDTA-Na2） decalcification, and to measure the bone mineral density and biomechanical characteristics of porcine 3-connected vertebra, and to explore a method of making osteoporotic compression fracture model in a short time. Methods Forty-nine 3-connected fresh porcine thoracolumbar vertebra were randomly divided into 7 groups, marked as A, B, C, D, E, F, and G. There were 7 specimens in each group. The specimens of B, C, D, E, F, and G group were dipped into 0.4916 mmol/L EDTA-Na2 decalcification solution. Bone mineral density （BMD）, biomechanical parameters, and micro-CT inspection were determined on day 0, 5, 7, 9, 11, 13, and 15, respectively. One specimen from each group was anatomized. Results General observation showed that hone trabecula of the specimens in each group became thinner and the gap between the trabecula became wider gradually along with the extension of decalcification time. BMD test showed a decrease trend, and the BMDs measured before and after decalcification were significantly different in each group （P = 0. 0000）. The compression strength decreased along with the extension of decalcification time. The compression strength before and after decalcification was significantly different in each group （ P = O. 0000 ）. Micro-CT detection on day 13 after the decalcification showed that BMD, TMD, BVF SMI, Euler number, and connectivity density had significant change （P ≤ 0.02）. Conclusion Decalcification with 0.4916 mmol/L EDTA-Na2 for 11-13 days can simulate osteoporotic vertebral compression fractures. It is a fast, feasible, and reproducible method.