Hayashi K, Markel M D, Thabit G, Bogdanske J J, Thielke R J
Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison 53706, USA.
Am J Sports Med. 1995 Jul-Aug;23(4):482-7. doi: 10.1177/036354659502300419.
To evaluate the effect of laser energy at nonablative levels on the mechanical properties of joint capsular tissues, we tested the femoropatellar joint capsules of 12 mature New Zealand White rabbits. Specimens were divided into three treatment groups (5, 10, and 15 watts) and one control group. All specimens were first nondestructively mechanically tested to determine stiffness and viscoelastic properties and then treated with laser energy or served as a control. Shrinkage was recorded and mechanical testing was repeated. The application of laser energy resulted in 9%, 26%, and 38% reduction in capsular tissue length for the 5, 10, and 15 watt groups, respectively. Tissue shrinkage was significantly and strongly correlated with energy density. Laser energy caused a significant decrease in tensile stiffness only in the 10 and 15 watt groups. Laser energy did not change the relaxation properties at any energy density. This study demonstrates that significant capsular shrinkage can be achieved with the application of nonablative laser energy without detrimental effects to the viscoelastic properties of the tissue; although at higher energy densities, laser energy did lessen capsular stiffness properties. The results of this study should be interpreted with caution until in vivo studies are performed.
为评估非消融水平的激光能量对关节囊组织力学性能的影响，我们对12只成年新西兰白兔的髌股关节囊进行了测试。样本被分为三个治疗组（5瓦、10瓦和15瓦）和一个对照组。所有样本首先进行无损力学测试以确定其刚度和粘弹性特性，然后接受激光能量治疗或作为对照。记录收缩情况并重复力学测试。对于5瓦、10瓦和15瓦组，激光能量的施加分别导致关节囊组织长度减少了9%、26%和38%。组织收缩与能量密度显著且强烈相关。仅在10瓦和15瓦组中，激光能量导致拉伸刚度显著降低。在任何能量密度下，激光能量均未改变松弛特性。本研究表明，应用非消融激光能量可实现显著的关节囊收缩，且对组织的粘弹性特性无不利影响；尽管在较高能量密度下，激光能量确实会降低关节囊的刚度特性。在进行体内研究之前，本研究结果应谨慎解读。
