Hi. I Have Arthritis In My Knees Which I Can

Hi. I have arthritis in my knees which I can cope with. In the last month or so I have had chronic pain in the back of my knees on the outer side (Tendon????). Thighs are stiff most of the time although I sit at work most of the day which probably doesnt help. Also of late when driving in excess of 100 miles a day I get a pain that starts in my right bottom cheek and goes down my leg to behind the knee so assume all is connected. I am 58. Thanks