This is a famous drawing:
What do you see?
Do you see the dainty, pert-nosed young beauty, her head turned away? Or the large-featured old hag?
If you see the young woman, and your friend sees the hag instead, your first reaction may be to scoff and say, “No way! Look again!”
Now, suppose you are studying cartilage defects in human knees and learn the following set of facts:
* Between 34 and 62 percent of people having knee surgery are found to have cartilage defects.
* Some 50 percent of athletes (from recreational to professional) who have cartilage defects don’t have knee pain.
* The vast majority of people with moderate knee osteoarthritis don’t have functional limitations.
What would you conclude?
Colin Hoobler, a physical therapist, connects the dots thusly in this Q&A:
“... it’s entirely possible that your knee pain isn’t caused by your cartilage defects, but something else (muscle weakness, inflexibility and/or lack of coordination).”
(A quick aside: the “lack of coordination” explanation for knee pain I find a bit odd; I’ve never encountered it before and it seems to make sense mainly if this lack of coordination causes you to fall on your knees a lot. :))
Now, if you remember back to last week, you’ll realize that on the matrix for knee pain treatment and beliefs, Mr. Hoobler probably belongs in the upper right corner (among those recommending treatment that is “Not Joint Focused”). He will work on addressing your muscle weakness, tightness and general klutziness.
That’s because, when presented with the group of facts above, he sees one picture. But might there be another picture here, if we look again?
It might be described like this:
“It’s entirely possible that your knee pain is caused by your cartilage defects, but you don’t have to get rid of them to become pain-free, as they’re actually quite common and don’t always cause problems.”
This is great news! This belief (that I didn’t have to restore my cartilage to a pristine state) sustained me during a long recovery from knee pain.
In fact, this was my thought process as I embarked on the journey:
“An MRI shows I have “mild” chondromalacia, but my knees are really crunchy and always inflamed. Any MRI is imperfect*, so maybe it hasn’t detected what’s really wrong with the cartilage (after all, chondromalacia starts with damage deep within the tissue). I’m betting the problem is with my cartilage. I can either despair -- oh no, it’s damaged and will never be perfect again -- or I can take solace in the fact that lots of people are walking around with defects and feel fine. I just have to strengthen the tissue slowly (and hopefully it will heal along the way, as it’s done in various studies). Yeah! I can do this!”
But why would some defects be painful while others aren’t? Recall that cartilage has no nerves. Hugely significant. So the tissue itself isn’t sending out pain signals, but rather nearby structures are. Pain may result when the cartilage becomes too thin or too soft or too ragged -- but it won’t be a problem with all lesions.
So when you look at your bad knees, what picture do you see?
* Serendipity! As I was writing this, along came this brief article saying that MRI exams underestimated the size of cartilage defects by 70 percent (compared with what surgeons actually found during an arthroscopy), according to one study. So that MRI that suggests you have a small problem, or no problem at all, may not be trustworthy.