Gretchen Reynolds
As an orthopaedic surgeon for almost 30 years, Howard Luks has come to dislike one string of words that crops up constantly in his work.
“Bone on bone,” he said. “I wish we could remove that phrase from medical discussions. I’ve seen it do so much unnecessary damage.”
Luks, 63, has built his medical practice, growing social media presence, and personal lifestyle and training around the idea that our joints, especially our knees, are capable of remaining strong and functional throughout life, with some basic care and feeding.
He often writes and speaks about how knee pain, stiffness, tissue tears and even bone-on-bone osteoarthritis “don’t have to limit you”. They “don’t automatically require avoiding activities” you enjoy or need. They don’t mean you’re just getting old.
But they may signal that it’s time to rethink certain aspects of our lives and health.
They almost certainly mean, Luks said, that it’s time to go for a walk.
To learn more about how we can best protect and nurture our knees, I spoke to Luks about how knees work, why they sometimes fail, the surprising reasons they become arthritic – it’s not all wear and tear – the power of lifting and how he handles his own sometimes “cranky” knees.
Why don’t you like the words “bone-on-bone”?
Over my career, I’ve had so many patients come to see me for a consultation or a second opinion, carrying an X-ray or an MRI scan, and they’ve been told they have bone-on-bone arthritis. So they think their knee is done, nonfunctional and they have to stop using it. They’re ready to quit running, playing tennis, using the stairs, even walking. And some of them weren’t feeling much, if any, knee pain before their diagnosis. But now they think they’re broken.
They’re not?
No. I tell people, “You are not your scan.” Just because someone has a meniscus tear [in the cartilage cushioning the knee bones], that doesn’t mean they’ll develop arthritis. And if they have some arthritis, it won’t necessarily progress to bone-on-bone. And if it does, even that doesn’t always mean they have to restrict activities. I have patients who are runners with bone-on-bone arthritis. They’re still running.
But don’t running and other high-impact activities, even walking, wear away cartilage? I’m a runner, and people constantly tell me I’m ruining my knees.
We’ve all heard that, but it’s a misconception. Moving and using the knee aren’t wearing away cartilage. Movement nourishes cartilage.
How so?
Cartilage doesn’t have a blood supply, so it can’t get nutrients from blood. It gets nutrition only from synovial fluid [the viscous fluid filling the knee joint]. When you take a step, you bend and load the knee, which diffuses the synovial fluid around and through the cartilage, delivering nutrients. The same movement initiates cellular processes that prompt the cartilage to start building new collagen and repairing itself. Using your knees keeps them in shape. The biggest mistake people with knee pain make is not moving. Rest is a four-letter word for knees.
But if wear and tear aren’t causing arthritis, what is?
It’s fair to say that the vast majority of cases of knee arthritis are not due to wear and tear. Some are. Knee injuries, like a torn ACL [a knee ligament] can change how people move, which contributes to wear and tear and, eventually, arthritis. Genetics play a role, too, though studies show it’s generally small. Being heavy also isn’t a major promoter of arthritis, which may seem counterintuitive. But people with obesity develop hand arthritis more often than people without obesity, which doesn’t make sense if arthritis is caused by excessive loading from body weight.
Then what’s left?
For me, based on the latest [scientific] literature, osteoarthritis is primarily a metabolic disease. Remember, cartilage is replenished by synovial fluid. We now know that fluid reflects your metabolic state. If you have metabolic problems, such as diabetes or other conditions, your blood will contain inflammatory molecules. Some of them will find their way into the joint fluid and then into your cartilage and set off inflammatory processes there. They also change certain cells that line the joint. In a healthy knee, these cells release substances that help cartilage regenerate. But in an inflamed knee, they switch character and start pumping out substances that make it harder for cartilage to repair itself. Now you have a knee primed to deteriorate and become arthritic. That process didn’t start inside the knee, though. It began with whole-body metabolic issues.
So, what can we do to avoid or deal with aching knees if we do have them?
My first ask with my patients is for them to walk 10 minutes every day. I tell them that exercise, almost any exercise, loads the joint and has benefits for metabolic health. But it’s good to start with something easy and achievable that most of us could do on the busiest or worst day of our lives. And if it winds up being seven minutes, not 10, that’s OK, and if it’s 12, that’s even better. Ultimately, I want them to walk for 30 to 60 minutes a day, if at all possible. Walking is medicine for arthritis. It improves metabolic health, lowers inflammation and decreases pain.
I also want them to strength train, which helps to stabilise and take some of the stress off the knee.
Some of them worry they’re not capable of exercise, though. They’ll say, “Oh, I can’t do this; I’m old”, or they think it’ll hurt or make their joints worse. And I tell them the truth: that it may feel hard or uncomfortable. But that doesn’t mean they can’t do it, or that they’ll grind cartilage away. You can feel discomfort without causing damage. And getting older doesn’t mean you can’t still train and adapt and grow.
Is that true even for people whose knee pain is intense?
In that situation, I usually tell people that, with some work, their pain can probably get better. But it’ll take time. By the time we’re in our 50s or 60s, very few things get better in just a few weeks. But for most people, even those in pain, strength training or walking can pay huge dividends. And for those who tell me, “I did all that and my knee is still killing me”, that’s why we do knee replacements.
What does your workout routine look like?
Well, I’m a bit of a lunatic. I regularly do 500 to 600 minutes a week of aerobic activity, but everything counts towards that. If I take my dogs for a hike, that counts. So does a six-kilometre walk. And I run three or four days a week, six to eight kilometres. I used to do a long run on Sundays, 16 to 24 kilometres. I don’t any more. I never want today’s workout to ruin tomorrow’s, and if I ran that long, I’d be wiped out the next day. Instead, to get my aerobic volume, I do long bike rides once or twice a week on an indoor trainer. It’s set up in front of a TV. I put on a movie and ride for two hours. It’s easy.
I’m also a rock climber. I just love the functional movements when you climb. And the grip strength. I do that once or twice a week. That’s my treat.
And I weight train, three days a week, minimum. I focus on adding muscle mass and strength, along with rotational work, power, balance and quickness. You need all of that for joint health and to maintain balance and avoid falls.
Are your knees still in good shape?
I have meniscus tears in both knees. The first happened 11 or 12 years ago. Most people over the age of 50 probably have a meniscus tear, even if their knees feel fine. So far, there’s no significant arthritis in either of my knees. My right knee does get a bit cranky on long runs. That hasn’t stopped me from running. I also do exercises at the gym that involve twists, turns and jumps, though they’re not always easy on my knees. But they’re foundational movements. If you don’t practise them sometimes, you’ll probably start avoiding them in your life, and then the narrowing starts.
The narrowing?
I’m 63, and what I’ve seen in many people my age is that life starts to grow smaller as people rearrange their lives around what they see as limitations. They stop taking the stairs because stairs can be hard if you have sore knees. But then they don’t visit friends who have houses with stairs. Or they don’t go to the movies because they’d have to walk too far from the parking lot. Or they don’t take their grandkids to the park or play with them on the floor because they’re worried they won’t be able to get up. And their world starts to narrow dramatically. They may not see it at first. But the more you avoid things, the more you lose the ability to do them, even if you later decide you want to. You’re also not helping your knees because you’re moving less and less.
I’ve seen this narrowing in my patients, my friends. I was worried about it in myself. So I made a conscious decision a few years ago to change my workouts, to make sure I was doing things that I might have thought I’m too old to do. So now I’m jumping on and off boxes and hopping from side to side at the gym. I want healthy knees, sure. But, even more, I want to build and strengthen the capabilities I need to broaden my life and keep it fun and interesting for years to come.
This interview has been edited for length and clarity.
The Washington Post
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