Take ginger, I use 400 mg. capsules twice a day, with/after meals because it’s such a good digestive aid, and an exercise.
The ginger is a powerful anti-inflammatory; that’s how it works. Other things are anti-inflammatory, too; but only ginger is $4 at Walmart for an almost-two-months supply. Before trying this I checked with Dr. Andrew Weil’s writings; he’s the dean of natural medicine. Literally dean; he has his own department at a state university. He agrees, but recommends 400 mg. daily.
Ginger works a little bit each day; it takes 3-4 weeks to notice a difference. For me and everyone I’ve told it fixed knee pain. Over. Done. 
Exercise: stand up from sitting without using your hands and with toes no further back than under your knees. Do five times, a few times a day. This strengthens the muscles along the sides of your hips, taking some strain off of your knees. I don’t do this often, but definitely feel it when I do. The ginger works on its own.