Knee Osteoarthritis query. Verify this?

Last year my mother started to have knee pain in her left knee. Took her to an ortho doctor, x ray showed knee osteoarthritis and he prescribed medicines but didn't help much. He suggested surgery but mother wanted to try physiotherapy. She's only had a few sessions but physiotherapy has helped. My query is few months before her knee pain started she was hospitalised for kidney stones. After the stones were removed, doctor changed her diabetic medicines. Instead of taking Cerapin xr 500 during breakfast and dinner he prescribed Trajenta 5 during breakfast and Gluconorm SR 850 during dinner. I read Trajenta 5 side effect can cause joint pain. Can any doctor verify this? My mother doesn't have any visible swelling or redness in the knees.