We all want to know what will make a knee replacement more successful. Here's one thing that wont: money.
A recent study looked at results from knee replacement surgery, and found that lower income patients had more successful results following knee replacement than a group of higher income patients.
Exactly why this is the case is unclear, but the authors speculate that perhaps lower income patients tend to delay replacement surgery. When it finally comes time to have surgery, they may feel a greater sense of improvement.