Bottlang Michael, Mohr Marcus, Simon Ulrich, Claes Lutz
Biomechanics Laboratory, Legacy Clinical Research and Technology Center, 1225 NE 2nd Avenue, Portland, OR 97232, USA.
J Biomech. 2008;41(3):701-5. doi: 10.1016/j.jbiomech.2007.10.024.
This study evaluated the feasibility of assessing continuous strain distributions on fracture callus cross-sections with an electronic speckle pattern interferometry (ESPI) system. Mid-sagittal callus cross-sections were harvested from ovine tibiae. One low stiffness (LS) specimen and one high stiffness (HS) specimen were selected to evaluate the feasibility for strain acquisition over a range of callus properties. The HS specimen was 147 times stiffer in compression than the LS specimen. ESPI captured continuous strain distributions on both specimens. Peak strain was located adjacent to cortical boundaries in the osteotomy gap. In response to 5N compression, peak compressive strain of 5.8% in the LS specimen was over two orders of magnitude higher than peak compressive strain of 0.013% in the HS specimen. In conclusion, ESPI-based strain acquisition enables reproducible quantification of strain distributions on callus cross-sections. Such measurements may support validation of computational models and evaluation of experimental results in fracture healing research.
本研究评估了使用电子散斑干涉测量（ESPI）系统评估骨折骨痂横截面连续应变分布的可行性。从绵羊胫骨获取矢状面中部的骨痂横截面。选择一个低刚度（LS）标本和一个高刚度（HS）标本，以评估在一系列骨痂特性范围内获取应变的可行性。HS标本在压缩时的刚度比LS标本高147倍。ESPI捕获了两个标本上的连续应变分布。峰值应变位于截骨间隙的皮质边界附近。在5N压缩作用下，LS标本的峰值压缩应变为5.8%，比HS标本的峰值压缩应变0.013%高出两个数量级以上。总之，基于ESPI的应变采集能够对骨痂横截面的应变分布进行可重复的量化。此类测量可能有助于验证计算模型以及评估骨折愈合研究中的实验结果。
