Methotrexate for pain relief in knee osteoarthritis: an open-label study

Objective. Synovitis is very common in knee OA and associated with pain. This open-label study evaluated an anti-synovitis therapy, MTX, for pain relief in knee OA. Methods. Inclusion criteria included pain visual analogue scale (VAS) > 40/100 mm, ACR clinical criteria for knee OA and intolerance/inefficacy of NSAID and opioids. US at baseline and 24 weeks assessed effusion and synovial thickness. Patients received MTX up to 20 mg/week for 24 weeks. Results. Thirty participants were recruited; mean age 64.5 years, median pain VAS 68 mm. At 24 weeks, 13/30 (43%) achieved epsilon 30% reduction in pain VAS, 7 (23%) achieved epsilon 50% reduction and 4 (13%) had worsened. Thirteen achieved Osteoarthritis Research Society International (OARSI) responder criteria. All had effusion/synovitis at baseline. There was no correlation between change in imaging and change in pain scores at 24 weeks. Conclusion. This open-label trial suggests analgesic efficacy for MTX in OA knee and suggests that a randomized controlled trial is warranted.