Osteoarthritis (OA) displays features of systemic and local inflammation, suggesting that DMARDs used in rheumatoid arthritis could potentially also be effective in OA. However, studies of the effects of DMARDs in OA have yielded conflicting data, and have been insufficiently large to draw conclusions. In this meta-analysis, we aimed to estimate the effect of DMARDs — such as methotrexate, hydroxychloroquine, TNF, and IL-1 inhibitors — on OA.

We searched for relevant articles of randomized controlled trials published up to March 2022, using Pubmed, EMBASE, and the Cochrane Library. Studies were reviewed in accordance with PRISMA 2020 guidelines. The effects of DMARDs on OA outcomes (symptoms, quality of life, ESR) were expressed as the standardized mean difference.

We retrieved 29 references. Among these, 23 randomized controlled trials compared the effects of DMARDs versus placebo or other treatments on disease activity, including 1143 DMARD-treated OA patients and 1155 OA patients in the control group. We found statistically significant improvement of pain and stiffness with methotrexate, especially in knee OA. TNF inhibitors improved the swollen joint count in hand OA, and inflammation parameters, without change in pain, stiffness, or function. Hydroxychloroquine and IL-1 inhibitors were not effective.

Overall, the presently available data regarding the effects of DMARDs on OA symptoms intensity are disappointing. Only methotrexate might have an analgesic effect, especially in knee OA, which warrants further investigation.