I Have Osteoarthritis. I Have Had Both Hips Replaced. I

I have osteoarthritis. I have had both hips replaced. I lost weight with bariatric surgery. When going back to working in hospital as Respiratory therapist, i got lots of pain under left knee. Both knees are miss cartilage. right knee has some bone on bone. I have had PT for hamstrings in past. I have had slight limp since left hip repair. Right hip got done in 2014, left was in 1998. So my question is : is the tendonitis and hamstring problem from bad right knee or bad left knee? I can only get one replaced at a time. I am going to get one done this spring. Do I do left or right? Now with rest and not working those hospital stairs and floors, I don't have that acute inflammation and pain but i want to be able to walk more and be active. I am 69 almost 70. I am 5ft 6" and 180 lbs. I was over 300 at my heaviest so know where the osteoarthritis came from.

oops can't afford to pay here. Medicare and Mutual of Omaha will pay my regular doctor