Mechanical environment alters tissue formation patterns during fracture repair
Mechanical environment alters tissue formation patterns during fracture repair
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DOI：
10.1016/j.orthres.2004.02.007
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发表时间：
2004-09-01
影响因子：
2.8
通讯作者：
Goldstein, SA
中科院分区：
文献类型：
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作者：
Smith-Adaline, EA;Volkman, SK;Goldstein, SA
骨折修复已被证明对力学环境敏感，但应变特性、大小和频率以及其他力学参数与组织形成之间的具体关系尚不清楚。这项研究的目的是利用在弯曲中受到机械刺激的愈合截骨的大鼠模型，将愈合骨折间隙内的应变分布与组织形成模式相关联。基于真实组织分布的有限元模型被用来估计骨折间隙内应变的大小和空间分布。再生组织的空间分布通过显微计算机断层扫描和组织学来确定，并通过逆转录聚合酶链式反应(RT-PCR)来确认。结果表明，在机械刺激期间，拉伸应变抑制了软骨的形成。然而，在刺激结束后，拉伸应变增加了软骨生成，随后迅速形成了骨。相反，在受压环境中，骨主要是通过膜内骨化形成的。综上所述，这些结果表明，与间歇性压缩应变和未刺激的骨折相比，骨折修复过程中的间歇性拉伸应变会刺激软骨内骨化，并促进最终的骨愈合。对这些关系的进一步了解可能有助于提出改善骨折修复过程的最佳治疗策略。(C)2004年骨科研究会。爱思唯尔有限公司出版。保留所有权利。
Fracture repair has previously been shown to be sensitive to mechanical environment, yet the specific relationship between strain character, magnitude and frequency, as well as other mechanical parameters, and tissue formation is not well Understood. This study aimed to correlate strain distribution within the healing fracture gap with patterns of tissue formation using a rat model of a healing osteotomy subject to mechanical stimulation in bending. Finite element models based on realistic tissue distributions were used to estimate both the magnitude and spatial distribution of strains within the fracture gap. The spatial distribution of regenerating tissue was determined by microcomputed tomography and histology, and was confirmed using reverse transcription-polymerase chain reaction (RT-PCR). Results suggest that tensile strains suppress chondrogenesis during the mechanical stimulation period. After stimulation ends, however, tensile strains increased chondrogenesis followed by rapid bone formation. In contrast, in compressive environments, bone is formed primarily via intramembranous ossification. Taken together, these results suggest that intermittent tensile strains during fracture repair stimulate endochondral ossification and promote eventual bone healing compared to intermittent compressive strains and unstimulated fractures. Further understanding of these relationships may allow proposal of optimal therapeutic strategies for improvement of the fracture repair process. (C) 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.