I had my right knee cartilage surgery last year... its now getting better, the left knee now started to get sore I can sense it similar (cartilage ) is this common if other knee?, likely other will go as well, been resting up now & again its sore, its not swollen at all, been taking pain killer for pain relieved before I took part at playing sport, its seems after doing warm up & starts running the pain seems disappeared. any advice?