Indian researchers have revealed that after three months of treatment with oral methotrexate, adults with primary knee osteoarthritis (OA) with inflammation had significant improvements in physical function and inflammation.

OA is a common joint disease that most often affects middle-age to older people. Many people with knee OA show clinical signs of joint inflammation, including swelling, warmth and pain. This study, from SSKM Hospital in Kolkata, India, compared oral methotrexate to placebo treatment with glucosamine, a common supplement for arthritis pain relief, in adults with primary knee OA. "Almost all patients with primary knee OA experience periods of warmth and swelling in the joint, with increases in pain and reduction of function," said the study co-author, Biswadip Ghosh from SSKM Hospital.

Those episodes are inflammation, and every episode damages the structures of the knees a little more. After some time, swelling subsides partly due to burning out of materials. "That leaves the knee in a hopeless state of function loss where physiotherapy helps minimally with enlistment for knee replacement. It will be helpful for patients if we can decrease the inflammation and rescue the joint," Ghosh added. Male and female patients with primary knee OA who had swelling and pain in both knee joints for at least six months, and also had evidence of OA on their X-rays, were recruited for the study.

Patients with signs of local inflammation, such as pain and swelling of the whole knee with warmth, were checked. Blood samples collected from all the patients and healthy controls were tested for selected biomarkers of osteoarthritis. Patients in the inflammatory group of primary knee OA were screened for other inflammatory arthritis with a clinical exam, blood tests, musculoskeletal ultrasound and X-ray, as well as MRI scans of their knees. They in the inflammatory group were then randomly allocated to take 15-20 mg/week of oral methotrexate or 1,500 mg/day of glucosamine as a placebo, then checked once a month for three months.

Patients were allowed to take acetaminophen or tramadol for pain if needed and were also given Non-steroidal anti-inflammatory drugs (NSAIDs) for 7-10 days at the beginning of the study to improve compliance. A total of 344 people with primary knee OA were included and examined from July 2016 to June 2019. The study's results showed that patients with primary knee OA with evidence of inflammation had significant improvements after three months of taking oral methotrexate. This new data suggests that methotrexate can be an effective intervention for people with knee OA who experience pain and inflammation.

"Our study provides hope to patients not only from this inexpensive molecule, methotrexate, but other therapies directed towards one cause of the disease: inflammation," Ghosh noted. This study is scheduled to be presented at ACR Convergence, the ACR's annual meeting which is happening online, November 5-9.