Swelling in right hip, knee and foot. Taken medicine, no results. How do I reduce swelling?

I m a male aged 70 years. Theonly exercise I do to maintain my health is brisk walking for 30 minutes every day. A month ago I had to stop my morning walk due to swelling in the right hip. On investigation by an ortohopaedic surgeon my knee was found to have damaged to some extent, but by then the swelling shifted from hip to below the knee extending to the entire foot . The surgeon advised me not to walk much because of the swelling. Though he gave medicines to remove the swelling it didn t work. It is not responding to ayurvedic treatment also. How can I get rid of the swelling and start walking?