Analgesic efficacy of low intensity laser therapy in a monosodium iodoacetate-induced osteoarthritic rat model

Abstract

[Purpose] This study evaluated the analgesic efficacy of low-intensity laser therapy (LILT) in a monosodium iodoacetate (MIA)-induced arthritis rat model. [Subjects and Method] Thirty Sprague-Dawley rats were randomly divided into 3 groups with 10 rats each: the normal, control, and LILT groups. The LILT group was treated with LILT using a gallium-aluminum-arsenide diode laser during the 3 weeks. Each group had 10 rats. All treatments were applied once a day, 5 days a week, for a total experimental period of 21 days. Weight-bearing shift, paw withdrawal threshold (PWT), and paw withdrawal latency were used as outcome measures. [Results] The hind paw weight-bearing shift, PWT, and paw withdrawal latency of rats in the control group were significantly lower than those in the normal group. In the LILT group, the weight-bearing shift, PWT, and paw withdrawal latency were significantly greater than those in the control group. [Conclusion] LILT reduces pain related behaviors of MIAinduced osteoarthritis in rats.