Why Do My Knees Hurt?

“Bend the knee,” a triumphant Queen Cersei tells Eddard Stark after outfoxing the nettlesome Northerner in “Game of Thrones.” 

When the noble Lord Stark declines, at great risk to his health, it is usually chalked up to an excess of probity. But what if he doesn't bend the knee because he can't bend the knee? The guy is no spring chicken. Maybe, faced with the choice of forcing his achy knee to bend one more time or losing his head swiftly and cleanly, he figures, “Enough already.”

Some of us baby boomers would understand.

As people age, it is often the knee that puts them on notice that their body is not always going to cooperate with whatever they have in mind. It may be stiffness. It may be weakness. It may be pain. But whether you’re just getting out of bed or walking onto the court, you know something has changed.

To a generation used to coming into the office on Mondays and swapping war stories about youthful-sounding injuries like shin splints and rotator cuff tears, the diagnosis may be unwelcome: arthritis. Osteoarthritis, to be exact, which is the most common form of arthritis in the knee.

The condition occurs as the cartilage that coats the bones at the joints and eases their passage, known as articular cartilage, wears away with use. Part of the problem is that with age, the chemistry of the cartilage changes so that it retains less water, making it more susceptible to stress, doctors say. Being overweight can make it worse.

But in the end, genetics, and the kind of cartilage you got from your parents, may play the biggest role. It is a little like buying tires, said Dr. Frederick M. Azar, chief of staff of the Campbell Clinic in Memphis and an official with the American Academy of Orthopaedic Surgeons. “You can get nice treads or you can get retreads,” he said.

It is not terribly surprising that when orthopedists open their doors, they see more and more baby boomers in their waiting rooms. After all, there are so many of them. But there is evidence that boomers may be seeking knee treatment in disproportionate numbers.

Some have suggested that this may be because members of the first generation to grow up exercising have put a lot of wear and tear on their bodies. But that is not clear.

“We say that, but we’re not sure of that,” said Dr. Letha Griffin, a staff member at the Peachtree Orthopaedic Clinic in Atlanta and a team physician for Georgia State University. Dr. Griffin noted that one of the best ways to avoid arthritis is to keep fit — and that means exercise.

Another reason some boomers may be seeking help, often asking about knee replacement surgery, is that they have greater expectations of their bodies. Once, people did not see a doctor until they could barely get around. “Now patients will say: ‘I can’t exercise. I can’t ride my stationary bike or regular bike or go for walks of one or two or three miles,’ ” said Dr. Mark W. Pagnano, an orthopedist at the Mayo Clinic in Minnesota.

If trends continue, many boomers will, in fact, have the surgery. But some doctors caution that it does not help everyone. And since the replacement knees have a limited lifespan, it is not clear how someone who has the surgery in his mid-40s will do later in life.

So doctors encourage patients with knee problems to try other approaches first. The orthopedics academy offers a number of recommendations. These include weight loss, exercises to increase range of motion and flexibility and devices that offer support to the knee. Dietary supplements like glucosamine and chondroitin may relieve pain for some, it says, though there is no proof that the supplements actually slow degeneration.

Doctors also advise patients to switch to exercises easier on the knee, like swimming and running on treadmills instead of on pavement. But they, too, can take a toll. So Dr. Azar often has to use a word that boomers don’t like to hear: moderation.