Thank you posting your query on ATD.
Your left knee is warm and painful as a result of more working knee joint due to right sided ankle cast.
Yes, it’s possible to have such situation due to the obvious reason you have explained.
In a person your age, osteoarthritis is very common, and it could be the reason you are experiencing pain and warmth. When the cushion in the joint is depleted, there is every chance those two bones brushing each other while you walk. There is also possibility of synovitis (infection of fluid in knee) of joint and osteomyelitis (infection of bones in knee)
For this, you will have to see a doctor to examine your knees.
Doctor may suggest MRI of the joint to assess whether there are any torn ligaments, inflammation, or the development of arthritis.
The more exercise the knee joint, the more you will be able to prevent pain. You may use knee brace while walking.
Your doctor may advise you to take oral analgesic medication such as Advil, naproxen etc
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.