After recovering from knee replacement surgery, patients' physical activity levels with their new joint were significantly lower than what they expected going in, in a new survey.
"My take is that total knee replacement is primarily for pain relief, it's not a lifestyle intervention," said Ewa Roos, an osteoarthritis researcher from the University of Southern Denmark in Odense, who wasn't involved in the study.
After surgery, "you need to change your lifestyle, you need an exercise intervention to improve your recreational function," she told Reuters Health.
Knee replacement surgery, also called arthroplasty, involves replacing damaged cartilage and bone in the knee with an implant.
Dina Jones, the lead author of the study from West Virginia University in Morgantown, said most people who have the surgery are pleased with the results in terms of having less pain and gaining more day-to-day function.
But less is known about their hopes for recreational activities, such as participating in sports, yoga or gardening, and whether they are fulfilled.
Jones and her colleagues surveyed 83 patients with arthritis who were about to have a knee replaced, then questioned them again one year after the procedure.
At the time of surgery, study participants reported spending about two hours a week being active, mostly doing moderate-intensity activities such as yard work, strength training and walking.
The patients had high hopes for their post-surgery selves, expecting to spend about 23 hours per week exercising one year out.
In the second set of surveys a year after surgery, people were indeed more active than before -- but not as active as they had anticipated.
Rather than 23 hours a week, patients spent about 11 hours a week being physically active, according to findings published in The Journal of Arthroplasty.
Jones said the reason people's expectations don't match reality is likely because those expectations are rarely brought up in pre-surgery conversations.
Surgeons and patients don't typically discuss long-term exercise abilities following surgery, but usually focus on the knee's function immediately after the operation, researchers said.
"I think patients' priorities are, 'Am I going to be able to walk, am I going to have to use a cane or a walker?'" Jones said. "People aren't looking at whether down the road, 'Am I going to be able to golf or walk down the road or cycle?'"
Because patients don't always know what to expect, they may hope the surgery will let them exercise as much as when they were younger and not in as much pain, Jones said.
And people are at their worst movement-wise right before surgery -- when participants first answered the survey -- so they may also feel they can only improve from there.
Even if surgeons don't always discuss long-term exercise goals with patients, "from the data we've collected I don't see anything that says physicians are telling people they'll have more function than they used to," Jones told Reuters Health.
She and her colleagues are working on developing educational pamphlets and presentations that would help people manage their exercise-related expectations for after knee replacement.
Roos said it's important for doctors to have explicit conversations about how physically active knee replacement patients can expect to be in the future -- both for day-to-day activities like bathing and grocery shopping and for exercise.
People can be disappointed from having expectations that are too high, she said.
On the other hand, "if you don't have high expectations, there's no way you're going to have physical activity improvement. But what we're missing are the steps to (get there)."
If doctors know their patients want to be more physically active after surgery, they can refer them to rehabilitation or community-based exercise programs, Jones added.