Low-dose methotrexate of little benefit in knee OA with effusion-synovitis

In patients with knee osteoarthritis (OA) with effusion, the use of low-dose methotrexate does not appear to relieve pain or reduce effusion-synovitis, as reported in a study.

The study included 215 community-dwelling patients (mean age 60.4 years, 89 percent female) with inflammatory knee OA with effusion-synovitis on MRI. They were randomly assigned to receive treatment with methotrexate up to 15 mg weekly (n=108) or placebo (n=107).

The primary outcomes of knee visual analogue scale (VAS) pain change and effusion-synovitis maximal area change over 52 weeks were assessed in the intention-to-treat population. Secondary outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score and subscales, infrapatellar fat pad (IPFP) signal intensity alteration, and treatment response based on the Outcome Measures in Rheumatology Arthritis Clinical Trials–Osteoarthritis Research Society International (OMERACT-OARSI) responder criteria.

A total of 175 patients (81 percent) completed the trial. Compared with placebo, methotrexate did not produce significant improvements in VAS pain (between-group difference, 0.3 mm, 95 percent confidence interval [CI], −6.7 to 7.3) and effusion-synovitis maximal area (between-group difference, 0.1 cm², 95 percent CI, −0.8 to 1.0) over 52 weeks.

Likewise, results for the secondary outcomes did not significantly differ between the methotrexate and placebo groups.

Adverse events occurred in 32 patients (29.6 percent) in the methotrexate group and in 26 patients (24.3 percent) in the placebo group.