Got ‘bad knees’? Why osteoarthritis is misunderstood.

Almost 120,000 Australians had a hip or knee replaced last year because of osteoarthritis. Most were women. But there’s still a mythology around the disease.

That figure represents a 95 percent increase in the number of new hips and a 139 percent increase in new knees compared to 20 years ago.

Jill Margo, health writer for the Australian Financial Review, noted in February that 75,000 people were waiting for one or other of those operations.

Why such demand? Artificial joints have gotten better, and we boomers have gotten older, and importantly, fatter.

What’s often not recognised is that around two-thirds of people with osteoarthritis (let’s call it OA for short) are women. More on that later.

OA mostly shows up in the hands, spine, hips and knees, often with pain, stiffness or swelling.

The myth is that it’s wear and tear of cartilage. As a result, a lot of people who have it think their bodies are just old and going to rack and ruin.

While it does show up more often after middle-age and can be linked to repetitive work that overloads particular joints, that’s not the full story.

So what’s OA about?

First, it involves the entire joint, not just cartilage. Bones in the joint can become weaker, spurs can form around the edges, the tissues that hold the joint together deteriorate, and the inner lining gets inflamed.

The problem though is inflammation. Overuse (or wear and tear) is just one trigger for it in a joint. Others include our genes and injury.

Joints aren’t the only parts of us impacted by inflammation. Two-thirds of people with OA have other inflammatory health issues. For example, there’s a major overlap between OA, diabetes and heart disease.

But the single biggest risk factor seems to be excess weight. While extra kilos add to the load on weight-bearing joints, fat is chemically active, releasing proteins that travel around our bodies causing inflammation.

Even in a non-weightbearing body part like hands, OA is about twice as common in obese people compared to lean people.

This could be one reason why so many women are affected. While men tend to be more overweight or obese than us, we’re more likely to have a riskier waist size, meaning we carry more fat around our bellies.

Other factors contributing to the higher incidence in women could be hormonal and anatomical.

Estrogen is a wonderful anti-inflammatory, so when we lose the benefits of it after menopause inflammation ramps up.

It’s also thought that our wider-hipped female anatomy adds to the stress on our knees because our thigh bones angle inwards. Knee OA is a particular issue for women.

What can we do besides joining the waiting list for surgery?

It’s understandable that the idea of a new hip or knee would be attractive if your own hurts. But it’s important to recognise that, as a friend who acquired a new knee six months ago says, “it’s major surgery and bloody hard work”.

It’s a pity that many people in that situation either don’t know about or don’t pursue exercise.

For example, US data shows that nearly 80 percent of women with or at risk of knee OA don’t meet the guidelines for physical activity (roughly 150 minutes — e.g. 30 minutes times five — a week).

The trouble with so many women not being active enough to meet that guideline is that if we lose strength, we lose capacity, and our joint health can get worse. Our risk of falling also dramatically increases.

On the other hand, being physically active can help to reduce pain, and improve function, strength, balance, heart health, and weight.

In addition, it can boost our mood. Living with pain, feeling restricted, and having difficulty sleeping would eat away at anyone’s quality of life. About one-third of people with OA have depression, and exercise can play an important role in alleviating that.

A major stumbling block to encouraging people with OA to exercise though is the language we use around the disease, such as ‘bone on bone’, ‘wear and tear’, and ‘degeneration’.

Anyone who thinks their body is already falling apart is likely to worry that physical activity will make things worse.

But a team of European and Australian scientists last year published a study comparing exercise with drug treatment for arthritic knee pain. Exercise outranked anti-inflammatory and opioid medications. It’s not often appreciated that exercise itself is anti-inflammatory.

What kind of exercise are we talking about?

The two most beneficial types for OA appear to be aerobic and resistance exercise, though it’s fair to say that there’s been better quality research done in these areas than on other kinds of exercise.

Lower impact aerobic exercise such as walking, cycling or swimming minimise stress on joints while improving heart health and increasing energy and stamina.

The goal is at least 30 minutes on three or more days of the week. On top of that, it helps to do at least 6000 steps a day in general activity.

Exercise in the water can work well because the buoyancy allows us to move with less pain. If land-based walking is uncomfortable, we can try it in a pool.

Resistance exercise twice a week increases strength and seems to be the most beneficial for mental health.

While the research points to aerobic and resistance exercise, there’s an argument for all of us, whether we have OA or not, to practice balance. Tai chi or yoga might tick that box.

Regular stretching might help with pain and is worth trying, but research here is patchy.

If we have OA some joint pain with exercise is normal, but it should resolve by the next day, and in the long run can make a big difference on several fronts.

It’s wise to start small and gradually increase how often, how long and how hard we do it, according to what’s manageable. And try not to sit for long periods.

Surgery is vastly more successful than it once was, but it’s not always the fix we’re hoping for. And artificial joints don’t last forever — about 20 years is the current estimate. Another benefit of exercise is that it can help delay the need for surgery.

So it makes sense to give it our best shot before joining that very long waiting list.

Photo Source: Bigstock