老龄对腰椎松质骨冲击力学特性的影响

目的腰椎松质骨的冲击力学特性对治疗骨质疏松、骨重建、骨再造以及人工关节置换术等具有重要的临床意义,本文对正常国人青年和老年新鲜尸体腰椎松质骨进行冲击试验,通过分析确定老年腰椎松质骨和青年尸体腰椎松质骨是否具有不同的冲击力学特性。方法死后1h之内解剖取出青年和老年死者腰椎L1-L5标本,并将标本沿纵向切成长30mm、宽5mm、高5mm的试样共40个,按年龄分青年和老年组各20个样本。以能量释放方法对2组样本进行冲击实验,根据试验机显示出的样本承受的冲击功,利用材料力学中的数学公式计算出每个样本的冲击韧性。结果青年组腰椎松质骨承受的冲击功为(35.92±3.26)N·mm,冲击韧性为(1.44±0.13)N·cm/mm2;老年组的冲击功为(28.2±2.94)N·mm,冲击韧性为(1.14±0.11)N·cm/mm2。结论老年组腰椎松质骨的冲击力学特性因老年性骨质疏松发生一定变化,其冲击力学性能显著降低。

The Impact of Aging on Mechanical Properties of Lumbar Trabecular Bone

Object It is very valuable to study the mechanical property of lumbar cancellous bone for the treatment of osteoporosis, bone remodeling, bone reconstruction, artificial joint replacement surgery and so on. This paper presents the impact tests of young and old lumbar cancellous bones, that definites whether the impact mechanical properties of old corpse spongiosa bone is different from younger＇ s. Methods In 1 hour of dying, forty specimens of lumbar vertebra L1 -L5 were obtained from 4 corpses, aged 22,28,68 ,and 70 years old, and divided into young and old groups, twenty specimens in each group respectively. And every sample was slivered into 30mm long, 5mm extending and 5mm high along longitudinal direction.. Then each sample was carried on the impact experiment by the energy liberation method. The maximum impact energy of samples were demonstrated on the test machine and the impact toughness were calculated with a formula. Results The impact e.nergy was （35.92 ±3.26）N·cm in youth group, and （28.2 ± 2.94） N·cm in old group. The impact toughness in young group was （ 1.44± 0.13） N·cm/mm^2, （ 1.14± 0.11 ） N·cm/mm^2 in old group.It was indicated that the impact mechanical property of old person＇ s lumbar vertebra spongiosa reduced because the senile osteoporosis changed.