Joint Replacement: Risks vs. Benefits

Medically Reviewed by David Zelman, MD on January 26, 2016
3 min read

After a skiing injury 30 years ago, Bert Pepper, MD, got osteoarthritis in his left knee. "I stopped skiing and gave up tennis, running, and other sports that are tough on the knee," he says. "I turned to speed-walking to stay fit, but the knee kept me from walking at a good pace."

As his pain got worse and walking became harder, he looked into having a knee replacement. It's not a decision to make lightly, Pepper says. "It's a major life event. You have to be prepared to lose a few months to pain after surgery, limited mobility, and vigorous rehabilitation."

And like any surgery, it's important to weigh the risks and benefits carefully.

"There are two main reasons to have a joint replacement," says Charles Bush-Joseph, MD, professor of orthopedic surgery at Rush University Medical Center. "The best reason is pain relief."

During a hip or knee replacement, a surgeon removes the damaged surfaces of the joint and replaces them with plastic or metal implants. This gets rid of the pain because the diseased cartilage and bone are no longer there.

The second reason is to improve how well your joint works, Bush-Joseph says, but these results are less predictable. After a new hip or knee is put in, many people can walk more easily. Some may be able to ride a bike or play golf. But there are no guarantees.

Joint replacements carry the same dangers as other major surgeries, like a chance of infections or blood clots. You're most at risk for these problems if you have heart disease, diabetes that's not well controlled, or a weak immune system -- your body's defense against germs. Your surgeon may prescribe antibiotics and blood thinners to try to prevent some complications.

The other major risk is that the new joint may not work as well as you hoped. It might feel weak or stiff, particularly the knee. "Patients who don't actively rehabilitate will not regain the maximum range of motion," Bush-Joseph says. To get the best results from your knee surgery, stick carefully to your rehab schedule of exercise, rest, and medicines.

It's less common, but it's possible that your implant can become loose or get dislocated. Also, keep in mind that your replacement joint can wear out after about 20 years. That means you may need another surgery down the road.

It may be the right choice if you're in a lot of pain and other treatments don't help. But you want to be sure that your knee or hip is actually the cause of your problem, says Michaela M. Schneiderbauer, MD, an orthopedic surgeon with the University of Miami Miller School of Medicine. "The source could be something other than the joint itself, even if arthritis is visible on an MRI."

If you actually have nerve or muscle pain, a joint replacement won't help, Schneiderbauer says. Your doctor can tell the difference if he does a careful physical exam and asks you questions about what's hurting you.

A joint replacement can stop pain, but it can't restore the hip or knee you had when you were younger. You shouldn't expect to move the joint the way you did 20 or 30 years ago, Schneiderbauer says.

As for Pepper, he went forward with his knee replacement. After 4 months of intense rehab, the pain was gone. He's back to speed-walking and climbs 100 steps every day to keep his knee strong. On a vacation to Italy and Croatia, he wore a pedometer. "There were times when I comfortably walked 7 miles in a day," he says. "It feels like my knee now."

Pepper's advice: Consider a joint replacement "if pain is interfering with how you want to live your life."