Maeda Eijiro, Noguchi Hitoshi, Tohyama Harukazu, Yasuda Kazunori, Hayashi Kozaburo
Biomechanics Laboratory, Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, Japan.
Biomed Mater Eng. 2013;23(3):173-81. doi: 10.3233/BME-130742.
The present study was performed to investigate effects of ageing on biomechanical properties of healing tissues of the patellar tendon (PT) after the removal of its central portion. An entire one-third defect was made in the PT of 0.5 year- (0.5 yr) and 2 year-old rabbits (2 yr). After 6 or 12 weeks, the tissue regenerated in the defect and the remaining, residual tissue was examined biomechanically and histologically. Age-related difference in the PT length was only observed in operated tendons at 6 weeks, and in the cross-sectional area such difference was observed only in unoperated, normal tendons. At 12 weeks, tensile strength and tangent modulus of regenerated tissues in 0.5 yr were significantly higher than those in 2 yr. By contrast, these properties of residual tissues in 2 yr were significantly higher than those of 0.5 yr at 6 weeks. The histology of each of regenerated and residual tissues was essentially similar between the two age groups. Accordingly, ageing exhibited adverse effects on the mechanical properties of tissues regenerated in the central third defect of the PT. This may be due to high tangent modulus of normal and residual PT tissues in aged animals, which reduces the amount of mechanical stimulation applied to regenerated tissues during healing.
本研究旨在探讨老化对髌腱（PT）中央部分切除后愈合组织生物力学特性的影响。在0.5岁（0.5 yr）和2岁的兔子（2 yr）的髌腱上制造了整个三分之一的缺损。6周或12周后，检查缺损处再生的组织以及剩余的残余组织的生物力学和组织学情况。仅在术后6周的手术肌腱中观察到髌腱长度的年龄相关差异，而在横截面积方面，仅在未手术的正常肌腱中观察到这种差异。在12周时，0.5岁组再生组织的拉伸强度和切线模量显著高于2岁组。相比之下，在6周时，2岁组残余组织的这些特性显著高于0.5岁组。两个年龄组再生组织和残余组织的组织学基本相似。因此，老化对髌腱中央三分之一缺损处再生组织的力学性能产生了不利影响。这可能是由于老年动物正常和残余髌腱组织的切线模量较高，这减少了愈合过程中施加于再生组织的机械刺激量。
