Effect of Low-Power Helium-Neon Laser Irradiation on Collagen Fibril Thickness of Incisized Medial Collateral Ligament of Knee in Rat

Purpose: The aim of the present study is to investigate the effect of low-power Helium-Neon laser (LPL) on collagen fibril thickness of incisized medial collateral ligament of knee joint (MCL) in rat. Materials and Methods: MCL of right hind limb of 35 male adult sprague Dawley rat under general anesthesia were transversly incisized. Rats were randomly divitded into normal, control, first laser and second laser groups. Rats of first and second laser group were exposed 10mJ/cm2and 1.2J/cm2LPL daily respectively. Samples were prepared and examined under transmission electron microscope. Thickness of collagen fibrils were measured. Data were analysed using ANOVA Micrographs were studied descriptively. Results: Rough endoplasmic reticulum of second laser group at day 12 developed more than that of the control group. Diameter of collagen fibril of second laser group at day 12 were , increased which was compareable to normal group; however there were no significant differnces betwen this group and control and first laser group. Diameter of collagen fibril of first laser group at day 21 was higher significantly that of second laser group and control group, but significant differences were observed between this group and normal group. Conclusion:It is concluded that irradiation of low-power He-Ne laser on incisized medial collateral , ligament of knee joint of rats increase collagen fibrils diameter in comparison with control and normal group.