Efficacy of high intensity laser therapy in knee osteoarthritis: a double-blind controlled randomized study

Abstract
Objective The aim of this study is to investigate the effectiveness of high intensity laser therapy on pain, functionality, flexion range of motion (FROM), and ultrasonographic cartilage measurement in patients with knee osteoarthritis. Methods This study was designed as a double-blind randomized placebo-controlled study. Forty patients diagnosed with knee osteoarthritis according to the American College of Rheumatology criteria were included in the study. After obtaining written informed consent, patients were randomized into high intensity laser therapy (HILT) + exercise therapy (ET), and placebo laser (PL) + ET groups. Each patient was treated five sessions per week for 2 weeks. The outcomes measured were pain level and functional disability using the visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively. The femoral cartilage thickness measurement was made ultrasonographically, and FROM was measured with goniometry. Results Statistically significant improvements were detected in VAS, WOMAC scores, femoral cartilage thickness, and FROM at the end of the treatment (in week 2) compared to the pre-treatment period in both groups (p < 0.05). There were significant decreases in the VAS and WOMAC scores of both groups in the 6th week compared to the pre-treatment period, and the results of the FROM and femur cartilage thickness measurements were increased at statistically significant levels (p < 0.05). The VAS and WOMAC scores were significantly lower in the 6th week in HILT + ET group compared to the PL + ET group (p < 0.05). Similarly, statistically significant increases were detected in the FROM and femur cartilage thickness measurements in HILT + ET group (p < 0.05). Conclusion HILT + ET combination was more effective in KOA than the PL + ET combination.