Knee replacements are typically less durable, satisfying, and flexible than a natural knee, and subsequent replacements often yield poorer outcomes.

“and unlike changing the tires on your car when when you have a new knee it's not the same as the old set it's not as durable it's typically not as satisfying it's not as flexible and so people don't have the same sort of euphoric outcome with their second knee replacement for instance than they do with their first”