The characterization of ligamentous soft tissue properties is limited by a lack of measurement methods capable of minimally-invasively quantifying regional strain. Previous implementations of radiographic imaging and tissue-embedded radiopaque markers demonstrated promising regional strain measurements, but found error associated with non-repeatable bead positions within the tissue after load application. No study has investigated the effects of cyclic loading on the strains measured within the tissue. The purpose of this study was to quantify the effect of joint loading on strain measurement using radiopaque markers and micro-computed tomography imaging. Six cadaveric porcine femur-anterior cruciate ligament-tibia complexes were instrumented with small diameter (0.8 mm) zirconium dioxide marker beads. The compound was imaged at 10 N then at 100 N of anterior force using micro-computed tomography. The bead positions in the images were used to calculate tissue strain between the 10 and 100 N anterior joint load conditions. Up to 100 intermediate joint cycles were applied, then images were acquired again at 10 and 100 N anterior force. No statistically significant difference was found between the strains measured before and after intermediate cycling (p > 0.05). This indicates that tissue loading did not introduce statistically significant changes to strains measured in tissue tested following this methodology.

中文翻译：

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将小直径不透射线跟踪珠插入前交叉韧带可在不影响材料特性的情况下进行可重复的应变测量。

韧带软组织特性的表征受到缺乏能够微创量化区域应变的测量方法的限制。以前的放射成像和组织嵌入的不透射线标记的实施证明了有希望的区域应变测量，但发现与负载应用后组织内不可重复的珠位置相关的错误。没有研究调查循环载荷对组织内测量的应变的影响。本研究的目的是使用不透射线标记和微型计算机断层扫描成像来量化关节载荷对应变测量的影响。六具尸体猪股骨-前交叉韧带-胫骨复合体装有小直径（0.8 毫米）二氧化锆标记珠。使用微型计算机断层扫描在 10 N 和 100 N 的前向力下对化合物进行成像。图像中的珠位置用于计算 10 和 100 N 前关节负荷条件之间的组织应变。应用多达 100 个中间关节循环，然后在 10 和 100 N 前力下再次采集图像。在中间循环之前和之后测量的应变之间没有发现统计学上的显着差异（p > 0.05）。这表明组织负载不会对按照此方法测试的组织中测量的应变引入统计学上的显着变化。然后在 10 和 100 N 的前力下再次获取图像。在中间循环之前和之后测量的应变之间没有发现统计学上的显着差异（p > 0.05）。这表明组织负载不会对按照此方法测试的组织中测量的应变引入统计学上的显着变化。然后在 10 和 100 N 的前力下再次获取图像。在中间循环之前和之后测量的应变之间没有发现统计学上的显着差异（p > 0.05）。这表明组织负载不会对按照此方法测试的组织中测量的应变引入统计学上的显着变化。