Just a brief history. I have had 3 tkr all on the same knee due to loosing. The last time I was at the orthopedic surgeon he told me that the other knee would have to replaced. The cartilage was completely gone in my left knee. He told me the bones were actually rubbing on each other. I also have a big bone spur, were his exact words.
I have had quite a few knee infections in the right knee and am a little concerned about a repeat of the same thing in the left knee.
Also, I've heard that there exist new injections for replacing cartilage...although I'm not sure what they're called. You might investigate more before committing to going under the knife again. In naturopathic medicine, invvasive techniques are generally the last resort.