She needn’t have worried.
“The knee felt good, and it was definitely worth it,” says Samuelson, 65, who won the first Olympic women’s marathon in 1984 and has set several world and U.S. records during her long running career. “I wasn’t able to run at all before, the pain was excruciating. My surgeons knew that I would be running on the knee with the intention of running marathons.”
Knee replacement, the most commonly performed joint replacement surgery, involves replacing damaged natural knee joints with artificial metal and plastic components. An estimated 634,000 Americans underwent knee replacement in 2019, according to the American Academy of Orthopaedic Surgeons (AAOS).
In Samuelson’s case, she had the lateral — or outer — part of her right knee replaced.
The downside for her and other athletes, even recreational ones, is that engaging in high-intensity sports after knee replacement can cause excessive wear and loosening of the new components, and may require more surgery. Knee replacement doesn’t mean quitting exercise — in fact, doctors encourage physical activity. But it might mean switching to something that involves less “pounding” or adapting your workouts in ways that lessen the impact.
“Most orthopedic surgeons want you to be active but not abusive,” says Nicholas DiNubile, a Philadelphia-area orthopedic surgeon and spokesman for the AAOS. “High-load repetitive impact is not ideal. A distance runner who is coming down hard on one leg at a time might have to consider a mind-set change.”
In Samuelson’s case, more marathons could mean a total replacement. “It was said at the get-go that I probably would be a candidate for a total at some point,” she says. “I was willing to take that risk.”
Younger patients join the fold
Until recently, knee replacement was largely the province of elderly patients with osteoarthritis. But experts say more younger people are seeking replacements now.
“It’s not uncommon to have patients under 50,” says Mohamad Halawi, associate professor of orthopedic surgery at Baylor College of Medicine. “Also, as techniques and materials improve, surgeons are more comfortable pushing the envelope for younger patients.”
Mike Cook, 46, a heavy-equipment operator and mechanic who lives in Port Washington, N.Y., is one such patient. In April, he underwent a partial replacement on the inside of his left knee. Years of strenuous work had worn out much of the knee’s cartilage, and he had to give up mountain biking, his passion.
Before the surgery, he says, “I couldn’t walk. I had intermittent sharp pains that were crippling.” Even though he still is recovering, “the pain is gone, and I’m 100 percent better than before,” he adds. “I have no regrets. None.” As for getting back on that mountain bike: “I can’t wait,” he says.
Most people choose knee replacement when their pain becomes unbearable. “I tell patients: You are ready if your knee starts making your plans for you, or breaking plans for you, when you start giving up the things you love,” DiNubile says.
Bernie McCabe, 54, of Haverford, Pa., underwent total knee replacement in both knees when he was 48 because of osteoarthritis and sports-related injuries. “I’d reached the point where I couldn’t do anything,” he says. Since his surgery, he still can’t run or play pickup basketball, but he plays tennis, hikes and walks 18 holes on the golf course. “I could never have done that before,” he says. “Getting this done was one of the greatest things in my life.”
Eddie Frank, 71, a high-altitude trekker and founder of an adventure travel company, agrees. Hobbled by osteoarthritis, he underwent partial replacement of both knees in 2018. After recovering, he climbed Mount Kilimanjaro for the 54th time. “The surgeries gave me my life back,” he says. “I have no pain whatsoever. My knees will probably outlive me.”
Recommended sports and exercise post-surgery
Experts encourage knee replacement recipients to exercise, but they recommend activities such as cycling, brisk walking, swimming, doubles tennis (which involves less stress because two people on each side of the net share the effort), elliptical machine workouts, gentle downhill skiing and hiking, among others. Repeated pounding can take a toll on a new knee, which is why basketball and long-distance running post-surgery can be problematic. But surgeons recognize that many athletes will be reluctant to give up such sports.
“For someone whose whole being is running or playing basketball, you have to have an educated conversation,” says Christopher Annunziata, an orthopedic surgeon and the head team physician for the Washington Commanders football team. “You have to explain the potential risks. It’s not something we would necessarily recommend, but we are not naive to the fact that some people will keep doing it.”
Halawi agrees. “I usually advise them to use caution and moderation,” he says. “They feel amazing after surgery and want to resume what they were doing before. My goal as a surgeon is not to restrict them but advise them.”
Jacqueline Hansen, 74, who won the women’s division in the 1973 Boston Marathon and, in 1975, became the first woman to break a time of 2 hours and 40 minutes in a marathon, had total knee replacement in both knees because of osteoarthritis, the first in July 2021, the second in February 2022. (There is no evidence to suggest running causes arthritis; in fact, research shows it actually may protect the knees.)
Her doctor, too, told her to forgo high-impact workouts, and she listened.
“My doctor said if I do not run or jump, there’s no reason these knees won’t last 20 years. If I do run, he will see me again in five to 10 years,” she says. Hansen had already stopped running several years before because of pain and swelling in her knees and had shifted to taking long walks or hikes. But “when those became too painful, and walking was only possible on a cane, and I was totally bowlegged, I had to face the inevitable and decide on surgery. I am so grateful to walk again without pain that I am not missing the running.”
Becoming just ‘partly bionic’
Those who have partial replacements such as Samuelson probably can keep running for a time, because the procedure removes only the affected knee parts but leaves some of the ligaments and natural shock absorbers intact. In a total replacement, however, the surgeon removes all three knee compartments — the medial, or inner side of the knee; the patellofemoral, or front of the knee; and the lateral, or outer side of the knee — and replaces them with parts made of metal and plastic.
“The ability to run with a partial is different from having a total,” says Thomas Muzzonigro, a Butler, Pa., specialist in knee and hip replacement. “You’re running partly bionic and partly yourself.”
Partial knee replacements remain far less common than full replacements. In 2019, there were only about 28,500 partial replacements, according to the AAOS. That’s partly because many patients don’t see a surgeon until the damage worsens, affecting the entire knee, or even both knees. In addition, says DiNubile, only certain patients are good candidates for partial replacements — specifically, they should be relatively young with “very specific wear patterns” and arthritis that affects only one knee compartment; they can’t be too knock-kneed or bowlegged, and they should be pretty lean.
But for some people, partial replacement is the answer. Because it is less invasive than a complete replacement, “people tend to feel more normal,” says Annunziata, who no longer does knee replacements. “We have seen people with partial replacements get back to the higher level with no problems, but we don’t know how long they can keep doing that before the knee starts to break down.”
Caution is important for those with partial replacements, because going from a partial replacement to a total one can be complicated. There often is existing scar tissue and debris from metal or plastic that has become worn, experts say.
Samuelson’s right knee had been problematic for years, starting with a ski racing accident in high school. She broke her right leg, leaving it shorter than the left and causing a biomechanical imbalance in her stride. She won the 1984 Olympic marathon trials race only 17 days after arthroscopic surgery in the same knee, also on the lateral side. By her estimate, she has put about 150,000 miles on her knees.
She knows she must be careful. She ran the London race on only about a third of her normal marathon training mileage (and still won her age group), and she is uncertain about whether there will be more marathons in her future.
“I won’t say yes, and I won’t say no,” she says, adding that she still hopes to earn the Abbott World Marathon Majors Six Star medal, awarded to those who complete the six major marathons: New York, Boston, Tokyo, London, Berlin and Chicago. She has run all of them except Tokyo.
“I don’t expect to be able to run marathons forever,” she says. “If I do have a total [knee replacement] at some point, I won’t consider any more marathons. But, with less mileage and cross-training, I’d like to think I can still do an occasional 5K or 10K, so I don’t have to stop running entirely.”