If you have a place to exercise in the water and swim it may be worth a try until you decide to have the surgery. My wife has a bum knee and that type of exercise/therapy helps a lot to limit pain and maintain strength and range of motion.
Maybe warm water, in Hawaii, might work!!
I think it might have been the weather change. Was fine until last month then bammm....
I used to swim in a heated salt water (sea) pool. Well, just floated around in it -- awesome!!