Methotrexate in Knee Osteoarthritis

I've been pondering about an article on methotrexate (MTX) in knee osteoarthritis (OA), which had been published in 2014. As it had been a double-blind, randomized controlled trial. It’s well worth to have a look at it. The article had been published in the Annals of Rheumatic Diseases (Ann Rheum Dis doi:10.1136/annrheumdis-2013-204856).

A. Abou-Raya and colleagues:

"Methotrexate in the treatment of symptomatic knee osteoarthritis: randomised placebo-controlled trial". Methods: "One hundred and forty-four patients with primary knee OA were randomised in a 1:1 ratio to receive up to 25 mg/week oral MTX (n=72) or placebo (n=72) for 28 weeks." Conclusions: "MTX significantly reduced pain and improved synovitis. There was a significant improvement in physical function. MTX may be a therapeutic option in the treatment of pain and inflammation related to knee OA."

If you closely at the methods in the abstract, you don't see the flaw (maybe it isn't a flaw - we'll look closer into it later). The objectives, however, already give us a hint: "To assess the efficacy of methotrexate (MTX) in decreasing pain and inflammation in symptomatic knee osteoarthritis (OA)." If you look it up in the whole text, you see, that randomization took place after an entrance exam and patients were not consecutive in the manner of reflecting patients with "symptomatic knee osteoarthritis", instead we're looking at a subset of patients, most of whom were overweight women in their mid-60s with advanced knee OA and clinical evidence of synovitis. The text doesn't explain if any are suffering from concomitant rheumatoid arthritis.

What does the study really say? There might be a subset of knee OA patients, who might benefit from MTX. Then why not say so clearly? The headline doesn’t tell exactly, what the study is about. I think, we're far from using MTX in knee OA patients in daily practice; but as were lacking drugs to alter the course of osteoarthritis, some more scientific effort is warranted. If MTX turns out to be a drug for even only a subset of knee OA patients, we're indebted to A. Abou-Raya and colleagues.