Amount of arthritis, pain often don’t correlate

Maybe you really won’t need that knee replacement

While giving an address to students at Harvard Medical School in 1944, Dr. Charles Burwell, the dean of students at the time, made a statement that has been re-quoted over the years. He said, “Half of what we are going to teach you is wrong, and half of it is right. Our problem is that we don’t know which half is which.”

While intended to be humorous, one could interpret that phrase to mean that as research evolves, what we once believed as fact is often proved untrue.

One area that Burwell’s wisdom is proving to be correct is osteoarthritis, commonly known as wear and tear arthritis. Historically, when osteoarthritis was discovered on an X-ray or MRI, it was thought to be the source of symptoms if someone had pain in that area. While that may be the case, recent research paints a different picture.

Because osteoarthritis is prevalent in knees, extensive resources have been dedicated to increasing knowledge over the past several decades. As a result, we have been enlightened with several fascinating facts.

The first is that 50% of people with radiologic findings of knee osteoarthritis do not have knee pain. The second is that the severity of imaging findings often doesn’t correlate to the severity of pain.

For example, some people with severe osteoarthritis may have minimal or no pain, while others with mild osteoarthritic changes may have significant pain.

To bring that to life, I often use a scenario consisting of 10 people with varying levels of osteoarthritis in their knees, ranging from very mild to more severe. If you lined those people up side by side according to their degree of osteoarthritic changes and then lined them up based on their level of pain and disability, you would likely get two different lineups. Some people with very mild osteoarthritis (or even no arthritis) would have severe pain and disability. Others with more advanced osteoarthritis would have minimal (or even zero) pain and disability.

The research tells us that there is a poor correlation between imaging findings and pain. Since painless and painful findings can look the same on an image, it is often difficult to determine if (or why) someone hurts based on their image alone. Because of that, recent guidelines have suggested that we shouldn’t use imaging as our primary focus when guiding treatment in osteoarthritis patients. And it doesn’t apply to just knees. These same principles apply to every joint in the body, whether that be the hips, shoulders or the spine, to name a few.

When you take that information further, osteoarthritis might not even be the pain generator in those with symptoms since osteoarthritis isn’t always painful. This opens the door for other pain-producing mechanisms, which can often be treated without addressing the osteoarthritic changes. For example, one study shows that 40% of patients with osteoarthritis on a waitlist for a knee replacement responded well to movement in a specific direction, termed directional preference. Intervention was not directed toward osteoarthritis in that subgroup of patients. Therefore, jumping into interventions to treat osteoarthritic changes is unwise without first identifying other causes for symptoms.

Now, some joints need to be replaced, but that number is smaller when you consider other pain-generating mechanisms even significant osteoarthritic changes. That is excellent news, as patients are often given a grim prognosis once osteoarthritis is discovered, especially if it is more advanced.

Dr. Jordan Duncan writes a monthly online health column for this newspaper. He is with Silverdale Sport and Spine.