How to return to fitness after total knee replacement

When pain and stiffness from knee osteoarthritis make simple daily functions — walking, climbing stairs, and exercising — too difficult, it may be time to consider surgery. Total knee replacement can dramatically reduce pain and give you back a knee that works.

“Most people can perform all their normal daily activities after knee replacement,” says Rebecca Mercuro, a physical therapist with Mass General Brigham/Spaulding Rehabilitation. You can also achieve a high level of fitness, including returning to low-impact sports you may have abandoned because knee pain got in the way.

“The more prepared you are, the more you set yourself up for success,” says Mercuro.

Knee replacement recovery: What to expect

Many knee replacements are now performed as same-day procedures. “A physical therapist will teach you how to walk with a walker or crutches and go up and down stairs on the day of the surgery,” says Mercuro.

A physical therapist will often visit your home to help you start an exercise program. After about two weeks, you’ll begin outpatient physical therapy. This involves another six to 10 weeks of exercises to strengthen your leg and restore knee movement.

“By the time you finish physical therapy, you’ll be able to walk without a walker, crutches, or cane (if that was your baseline before worsening arthritis); navigate stairs; and return to a normal exercise and walking program,” says Mercuro.

How long does recovery take after surgery?

“Complete recovery can take six to 12 months, but you should be back to your normal daily activities within the first three months,” Mercuro says.

Some people choose to get a jump on rehabilitation by doing physical therapy before surgery, an approach often called prehabilitation, or prehab. Prehab involves working with a physical therapist to strengthen muscles and improve joint flexibility.

This can mean better function after the surgery. “Some studies show that your range of motion before surgery predicts how well you’ll be able to move after surgery,” says Mercuro.

After knee replacement: Regaining mobility

After surgery, it’s important to have realistic expectations. If you couldn’t walk more than a block for the past year, you won’t suddenly be hiking five miles, even if you were able to do that a few years ago. Your muscles have weakened, your aerobic capacity has declined, and your movement patterns have changed to adapt to pain. Reversing these changes requires time and effort. But it can be done.

“I had a patient return to high-performance biking events within a year of two knee replacements,” says Mercuro.

Whatever your personal physical activity goals are, be sure to communicate them to your physical therapist, who will help you achieve them. Age itself is not always a major barrier. “You can always get stronger, and you can always build your activity tolerance,” says Mercuro.

“Our main goal for people when they finish outpatient physical therapy is to be able to do around 20 minutes of daily activity such as walking, along with exercises to strengthen all major muscle groups two times a week,” she says.

It starts with simple goals like walking to the mailbox and back. Each day, you add a little more — another minute of walking, a few more repetitions of strengthening exercise. Over time, small steps add up to meaningful progress.

Safe exercises to return to fitness after knee replacement

Recovery doesn’t end when outpatient physical therapy concludes. In fact, this is just the beginning. “Remaining active after a total knee replacement is important for your success — motion is lotion,” says Mercuro.

You’ll be advised to engage in lower-impact activities such as walking, hiking, biking, swimming, golfing, strength training, and aerobic activities. If you want to swim, wait until the incision has completely healed.

Most surgeons recommend avoiding high-impact activities, such as running and jumping, to improve the life span of the joint implant. But this is not absolute. If you want to return to a particular sport or activity such as running, pickleball, or tennis, discuss it with your surgeon and physical therapist. This may require specialized training.

Some surgeons encourage patients to use a stationary bike daily, indefinitely, to preserve knee flexibility. Mercuro suggests finding forms of exercise that you enjoy and making them a part of your daily life. “Senior centers often have great programs for general exercise, flexibility, and balance to help with this,” she says.

How long does a knee replacement last? Recent data show that about 82% of total knee replacements last 25 years. With advancements in joint replacement technology and surgical techniques, newer implants may last longer.

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