Sunday, January 15, 2017

On Skepticism About Cartilage Healing

Recently I’ve seen some comments popping up questioning the idea that cartilage can heal. So I wanted to devote a post to that. Some of what I’m about to say will sound a bit different from what’s in Saving My Knees, because my thinking has changed somewhat. However, my belief that damaged cartilage can improve remains as strong as ever.

First, what’s changed: I don’t see knee pain through such a cartilage-centric lens anymore. Knee pain sufferers often do fine with some cartilage defects, and curing these shouldn’t become an obsession. I did note in the book that some people with cartilage defects have no knee pain; others that appear to have fine cartilage have lots of knee pain. Cartilage flaws and knee pain certainly don’t correlate perfectly.

Do I still think my problem was my knee cartilage? I think that was at least some of it, yes. My knees made awful crunching noises; they are much quieter now. But how much of that could be from improvements in the synovial fluid and how much from better cartilage? On that, I honestly don’t know. What’s changed in my analysis: I think some of my problem lay in the bone endings and could have been detected with a bone scan.

Again, these are just theories. What I do know is I had knee pain that the best doctor I saw said would never get better, and I smiled outwardly and inside I said, “Screw you, I think you’re wrong.” And I devoted more than a year of my life to proving he was. Recovering from chronic knee pain was the hardest thing I’ve ever done, and the achievement I’m most proud of (getting into Harvard was only about doing well on some tests and writing a good essay by comparison; I am extremely proud of my children, but they are their own accomplishment).

Occasionally – and I must say very occasionally, because this blog has some really terrific followers – I catch a whiff of a newcomer probing, trying to figure out what kind of fraud I might be. “Hmm, cartilage can heal? Curious that this fellow says so, when my doctor says it can’t, and my physical therapist says it can’t. But I bet you can sell a lot of books that way. So let’s see if he can produce some evidence that his cartilage regrew.”

(Please check out this post where I address head on the question “Why don’t you get a second MRI to show all the cartilage healing that you claim occurred?”)

My more expansive reply to a skeptic is: Don’t get distracted by thinking your end goal is to walk out the other end of the tunnel with pristine cartilage. That’s a waste of time. You need for the cartilage to get stronger, more resilient, more capable of handling day-to-day loads. Whether it’s once again as smooth as a baby’s bottom ... that’s not the main issue.

Today, I feel confident that mine is much stronger than it was than when I had constant knee pain.

But let’s backtrack for a moment and tackle the tough question directly. Can cartilage improve? Can it be restored in spots where it’s vanished? On this, don’t waste your time looking at my knees. Just consider the studies I cited in the book. There were two that I recall; they’re in the bibliography for anyone to track down.

Let’s consider one briefly. It’s called “A Natural History of Knee Cartilage Defects and Factors Affecting Change.” You can find it here (at least until it disappears behind a paywall, which I hope it never does, but one never knows).

What amazed me about this study, and I hope this came across in the book, is that researchers found that cartilage defect scores got better at about the same rate they got worse. Also, this was the same for knee pain sufferers as for pain-free subjects. At the time, the implications seemed mind-blowing. Changes in cartilage are a two-way street. You don’t just get worse.

So you may wonder: Well, those that got better, what were they doing differently? Answer: we don’t know. Notice this study is called a “natural history.” That means the point wasn’t to test whether walking or Pilates is better for rehabilitating bad knees; it was simply to observe the knees of more than three hundred subjects over a longish (two-year) period and see how they changed naturally.

Do you get why that’s so great? Think about it for a moment. People who weren’t trying to do anything in particular to “save their knees” saw an improvement in cartilage defects over this period. Imagine what they might have accomplished had they actually been trying to save their knees! I can’t tell you how much this study buoyed my hopes. I drank it down like a thirsty man with a glass of cold water and, once I fully grasped the implications, thought to myself, “Damn, I really can do this.”

And then there's also this other study (“Factors Affecting Progression of Knee Cartilage Defects in Normal Subjects over 2 Years”). It showed five cases where researchers saw bare bone on an MRI and two years later, in four of those cases, some cartilage had appeared (Rheumatology 2006, 45:79-84, page 81). That table I reference is in the upper left; an image showing improvement is below. Check it out.

Could it be that all these MRI readings were wrong, that the researchers are fraudulent, that the whole thing is some lousy hoax? Of course, but it’s also possible that my mild-mannered mother is secretly a Russian agent. Lots of things are possible. But what makes more sense: that we’d be created with bodies containing some tissue that just wears out, and that’s it, or that it have some capacity to heal, at least slowly? (After all, most of the rest of our body can heal; even neural networks can rewire after damage.)

I operated on the optimistic premise – not because I’m some dumb Pollyanna. I actually skew more toward the dark-humored pessimistic end of the spectrum. I operated on the optimistic premise because, at the end of the day, it seemed most rational. And it was.


  1. Richard, this is well written and a great example of how knowledge evolves with time, life experience and continued research.

  2. The other important point I learned after years of researching, and which needs to be brought out is that there are essentially 3 main areas of cartilage in each knee:

    1. The 2 meniscus (menisci?), one on the medial and one on the lateral side of each knee. These are C-shaped shock absorbing pads of cartilage which stop your femur and tibia (upper & lower) leg bones from banging together. Many parts of the meniscus have poor blood supply, so healing them if they tear is a problem. It can be done (Doug Kelsey did), but often if they are jamming in the joint or rubbing away other cartilage (like mine was), surgery is needed. BUT if you are young, ask about having the meniscus repaired rather than trimmed. Or if you are very patient and not too restricted, try healing it yourself by taking it easy for 6-12mths (wish I'd known that) - try to preserve as much of your meniscus as you can, as removing it definitely accelerates osteoarthritis (i.e. the nasty bone on bone action).

    2. The cartilage on the back of your patella (kneecap). When this gets damaged they call it 'patella chondromalacia' and I suspect that is the main source of cartilage damage in the knee which leads to the classic Dr Scott Dye 'loss of tissue homeostasis' when damaged. You get pain from the damaged cartilage (well from the underlying bone actually), and if you push that damaged patella hard enough, you get chronic inflammation of other knee structures like the synovial lining - this I'm sure was the source of most of my burning/aching pain and stiffness. Not cartilage damage per se, but other things triggered by cartilage damage and/or overload. This cartilage can definitely heal, but it is slow and takes care - you need to get on 'cartilage time' (think years, not months in my case). The things you do to heal it can also assist heal the synovial inflammation, though in my case I was so far gone and could not rest enough, so anti-inflammatory drugs were also required.

    3. The cartilage on the end of your femur & tibia. This can also heal with 'cartilage time' and I suspect could also cause other symptoms like in 2. above.

    So when people say their knee cartilage is stuffed, it is not as simple as that. Depending which cartilage is stuffed, the treatment options and outcomes can be very different. You should educate yourself on this before letting a surgeon open you up, as that might make you worse.

  3. TriAgain, I think you are absolutely right that patients must educate themselves before accepting surgical interventions that might not benefit them. Also, I have different take on chondromalacia. Dr Dye told me himself that his severe chondromalacia is totally asymptomatic. Apparently, many people have chondromalacia without being aware of it. The more I read, the less likely it seems that chondromalacia is a factor in most knee pain cases.

  4. Fascinating stuff. In the second study you cite "Of the five grade 4 defects, four (80%) reverted to grade 1, 2 or 3 (Fig. 2) and one (20%) did not change. Severe cartilage defects (grades 3 and 4) were more likely to revert to less severe lesions". I guess this could be because as you get closer to the bone then there's more potential for the "stuff" (bone marrow stem cells?) to come from the bone to aid the healing process.