Knee osteoarthritis (KOA) is one of the most common health problems around the world. According to this, several interventions have been used to treat this group of patients including pharmacological and non-pharmacological management such as weight reduction, behavior modification, and physical therapy. Recently, high-intensity laser therapy (HILT) has been used to treat patients with KOA. The results of previous studies showed that HILT could help to reduce pain as well as improved function in patients with mild to moderate KOA. However, there were still no standardized guidelines for HILT treatment in KOA. Also, no previous studies evaluated the efficacy of HILT in patients with severe KOA. The present study, therefore, recruited not only mild to a moderate degree but also severe degree. The study aim was to determine the efficacy of HILT in terms of pain relief in patients with mild, moderate, and severe KOA. The hypothesis was HILT would effectively reduce pain in patients with KOA compared to sham laser plus conservative treatment.

• This study is a double-blinded randomized control trial that compared the efficacy of HPLT to sham laser in patients with KOA.
• 42 patients who had KOA diagnosed by the American college of rheumatology (ACR) 2016 guidelines were recruited including a drop out of 20%.
• The participants were then randomly allocated into two groups (21 participants per group), mainly HILT and sham laser. Also, both groups received conservative treatment such as disease education, exercise, and advice for weight reduction.
• The intervention group received HILT which was applied on the medial, lateral, and posterior part of the knee joint. The total energy was 562.5 J per session which was done 2-3 sessions a week, for a total of 10 sessions.
• The control group received sham laser by the same device for 10 sessions plus conservative treatment as in the intervention group.
• The outcome measures, VAS and T-WOMAC score were recorded before and at the end of the study.
• Statistical analysis was performed using SPSS 18.0 version to evaluate the statistically significant change within the same group and the difference between groups.

Inclusion Criteria:

• Patients with primary knee OA diagnosed based on the American college of rheumatology (ACR) guidelines for early diagnosis of knee osteoarthritis 2016.
• Patients who had knee pain for at least 6 months and had VAS score greater than 4 out of 10 points
• Patients with knee OA who have Kellgren And Lawrence (KL) classification stages 2-4.

Exclusion Criteria:

• Patients who have secondary knee OA caused by other pathologies
• Patients who have a history of corticosteroid or hyaluronate injecting into the knee joint within the past 6 months
• Patients who were treated by physical therapy equipment within 1 month before the study
• History of stroke, bleeding disorders, cancer, deep vein thrombosis, cognitive impairment, or mental disorders
• Contraindicate to laser therapy