Effectiveness of high-intensity laser therapy in the management of patients with knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES: High-intensity laser therapy (HILT) has recently been used to control pain and symptom improvement in knee osteoarthritis. We performed a systematic review and meta-analysis of randomized controlled trials to assess the effectiveness of HILT in patients with knee osteoarthritis. METHODS: We conducted a search of articles in the MEDLINE, EMBASE, Cochrane CENTRAL, and Web of Science databases up to March 2020 for randomized controlled trials investigating HILT intervention, placebo, or active intervention as comparator groups for alleviating pain in knee osteoarthritis. Two independent reviewers evaluated the methodological quality and extracted pain and functional outcomes using a pre-specified form. A meta-analysis was performed using an inverse-variance random effect model. Heterogeneity was assessed using Higgins I-2 with p-values. RESULTS: Six randomized controlled trials (RCTs) were included in this meta-analysis. For VAS pain, 334 patients from four studies showed that HILT significantly decreased pain compared to the control (MD, -1.18; 95% CI, -1.68 to -0.69). HILT significantly improved WOMAC stiffness (SMD -1.00; 95% CI -1.32, -0.68) and function (SMD, -5.36; 95% CI -7.39 to -3.34) compared to the control. CONCLUSION: The effectiveness of HILT on pain, stiffness, and function in patients with knee osteoarthritis is promising. However, due to the limited number of studies, further randomized controlled trials with large, well-designed samples are needed.