(RxWiki News) Both rheumatoid arthritis and osteoarthritis patients may undergo knee replacement surgery if conventional treatments give little relief. The results of this surgery differ depending on the type of arthritis.
Rheumatoid arthritis patients have poorer results after total knee replacement surgery, compared to osteoarthritis patients. This difference in outcomes may be due to the expectations that rheumatoid arthritis patients have before surgery.
"Think positive before knee replacement surgery."
Even though rheumatoid arthritis patients do not have the same knee function after surgery as osteoarthritis patients, they are still satisfied with the results. A patient's satisfaction is gauged not only by improvements in pain and function, but also by the degree to which that patient's pre-surgery expectations were met.
However, researchers do not know if rheumatoid arthritis patients have different expectations than osteoarthritis patients.
In order to shed some light on this uncertainty, Lisa A. Mandl, M.D., of the Hospital for Special Surgery in New York, and colleagues compared the expectations of 64 rheumatoid arthritis patients to those of 124 osteoarthritis patients.
The researchers found that rheumatoid arthritis patients had lower overall expectations than osteoarthritis patients. They also had lower expectations with regards to individual items, including the ability to perform daily tasks like household chores and the ability to interact with others.
Rheumatoid arthritis patients had an expectation score of 73.7, a score of 100 being the highest expectations. In comparison, osteoarthritis patients had an expectation score of 79.8. According to the authors, that six point difference is "clinically meaningful."
The study's results also revealed that rheumatoid arthritis patients place a lower value on their health state before surgery, compared to osteoarthritis patients.
According to Dr. Mandl and colleagues, the lower expectations and poor view of their pre-surgery health "may explain the discrepancy between higher satisfaction and lower functional outcomes in [rheumatoid arthritis] patients."
The authors conclude that rheumatoid arthritis patients may be mistakenly accepting worse outcomes. It is possible that patients' expectations are working against their post-surgery results.
Dr. Mandl presented her team's findings at the annual meeting of the American College of Rheumatology. The study must be reviewed by a body of peers before it is fully accepted as credible evidence.