Many patients believe things about hip and knee replacement surgeries that are pretty far from what the research actually says about these surgeries. For example, many patients believe that most people have no pain after a hip or knee joint is replaced, but the research says most patients are still in pain. In addition, many patients believe these joint replacement surgeries are safe, yet the research says that there are serious complications such as a major increase in the rate a heart attacks after surgery. Finally, many people who can’t run before the surgery believe they will do so after the surgery, but the research shows that’s not likely.
Today’s highlighted new research concerns activity after these surgeries. Most patients that I have talked with believe their activity levels will be better after a hip or knee replacement. So what does the research say? A new study looked at patients who were waiting for hip or knee replacement versus those who had the surgery. The study authors actually measured how active the patients were using accelerometer devices (rather than relying on how active the patients thought they were). Based on the objective measurements, patients were no more active after these joints were replaced than they were before the surgery. Why? Based on the studies linked above, this finding fits a bigger picture. For example, if you weren’t running before the knee replacement don’t expect to do so after the surgery. In addition, many patients after these surgeries still have pain, so perhaps this is a barrier? Finally, many patients have gotten quite weak, so without a lot of work to turn that trend around, they likely just continue to be unable to move easily.
The upshot? Don’t expect that a hip or knee replacement surgery will magically solve your movement problems, as based on the research, it won’t. These are big surgeries that can help some patients, but the concept that we have high levels of evidence that they solve problems like low activity or allow most patients who weren’t participating in sports to do so after the surgery or become pain free isn’t supported by the research.