Osteoarthritis (OA) is a common disabling condition, for which no effective therapy currently exists.Synovitis is commonly demonstrated in knee OA imaging. Methotrexate (MTX) helps to decrease synovitis in many inflammatory joint diseases, particularly rheumatoid arthritis.Accordingly,the aim of the present study was to assess the efficacy of MTX in decreasing pain and inflammation.Eighty-eight patients with clinical and radiographic criteria of primary knee OA with knee pain, were included in this study.Patients meeting the eligibility criteria were randomized in a 1:1 ratio to receive either 25mg/week oral MTX(n=44)or placebo(n=44)for 16 weeks. The primary outcome measure was pain reduction and secondary outcome measures included improvements in physical function scores.There was a statistically significant reduction in pain and improvement in function in the MTX group compared to the placebo group at 16 weeks.

Inclusion Criteria:

• primary knee osteoarthritis
• pain not responding to the usual therapy
• synovitis

Exclusion Criteria:

• any other inflammatory conditions,
• hepatic and renal insufficiency