Hi Richard - My wife has had both of her knees replaced. She still has some pain but is doing well. Her biggest complaint is that she gets a patdown search everytime we go through security at a US airport. She has a card that says she has knee replacements but it doesn't cut any ice with the TSA folks - in order to not be accused of profiling they suspect Grandmothers just as much as young Arab men. My wife's mother has also had both knees replaced - it did wonders for her.