Williams Lakiesha N, Elder Steven H, Bouvard J L, Horstemeyer M F
Biomedical Engineering, Department of Agricultural and Biological Engineering, Mississippi State University, MS 39762, USA.
Biorheology. 2008;45(5):577-86.
In this study, we examine the transverse and longitudinal compressive mechanical behavior of the rabbit patellar tendon. The anisotropic compressive properties are of interest, because compression occurs where the tendon attaches to bone and where the tendon wraps around bone leading to the development of fibro-cartilaginous matrices. We quantified the time dependent viscoelastic and anisotropic behavior of the tendon under compression. For both orientations, sections of patellar tendon were drawn from mature male white New Zealand rabbits in preparation for testing. The tendons were sequentially compressed to 40% strain at strain rates of 0.1, 1 and 10% strain(s) using a computer-controlled stepper motor driven device under physiological conditions. Following monotonic loading, the tendons were subjected to stress relaxation. The tendon equilibrium compressive modulus was quantified to be 19.49+/-11.46 kPa for the transverse direction and 1.11+/-0.57 kPa for the longitudinal direction. The compressive modulus at applied strain rates of 0.1, 1 and 10% strain(s) in the transverse orientation were 13.48+/-2.31, 18.24+/-4.58 and 20.90+/-8.60 kPa, respectively. The compressive modulus at applied strain rates of 0.1, 1 and 10% strain/s in the longitudinal orientation were 0.19+/-0.11, 1.27+/-1.38 and 3.26+/-3.49 kPa, respectively. The modulus values were almost significantly different for the examination of the effect of orientation on the equilibrium modulus (p=0.054). Monotonic loading of the tendon showed visual differences of the strain rate dependency; however, no significant difference was shown in the statistical analysis of the effect of strain rate on compressive modulus. The statistical analysis of the effect of orientation on compressive modulus showed a significant difference. The difference shown in the orientation analysis validated the anisotropic nature of the tendon.
在本研究中，我们检测了兔髌腱的横向和纵向压缩力学行为。各向异性压缩特性备受关注，因为在肌腱附着于骨骼处以及肌腱环绕骨骼处会发生压缩，从而导致纤维软骨基质的形成。我们对肌腱在压缩状态下随时间变化的粘弹性和各向异性行为进行了量化。对于两个方向，均从成年雄性新西兰白兔身上获取髌腱切片以准备测试。在生理条件下，使用计算机控制的步进电机驱动装置，以0.1%、1%和10%应变率将肌腱依次压缩至40%应变。在单调加载后，对肌腱进行应力松弛测试。横向方向的肌腱平衡压缩模量经量化为19.49±11.46 kPa，纵向方向为1.11±0.57 kPa。横向方向在0.1%、1%和10%应变率下的压缩模量分别为13.48±2.31、18.24±4.58和20.90±8.60 kPa。纵向方向在0.1%、1%和10%应变率下的压缩模量分别为0.19±0.11、1.27±1.38和3.26±3.49 kPa。对于方向对平衡模量影响的检测，模量值几乎存在显著差异（p = 0.054）。肌腱的单调加载显示出应变率依赖性的视觉差异；然而，在应变率对压缩模量影响的统计分析中未显示出显著差异。方向对压缩模量影响的统计分析显示出显著差异。方向分析中显示的差异验证了肌腱的各向异性性质。
