Saturday, November 10, 2012

What Causes Patellofemoral Pain Syndrome and Chondromalacia?

I got this question recently.

It’s a good one because, unfortunately, the answers aren’t easy. But they are important to seek out. As I mention in Saving My Knees, my first law of healing is:

Before devising a plan to heal, you need to know what’s wrong and what’s causing it to be wrong.

So let’s start with what causes patellofemoral pain syndrome (often abbreviated “PFPS”).

Ah, that’s easy! It’s psst ... psst ... psst.

Seriously: there are two ways to answer this question.

One is that no one knows what causes it. No one knows because no one can know. There is no such thing as PFPS. PFPS is an overly broad, useless pseudo diagnosis that, when translated to its constituent parts from the bewildering medical terminology, means:

You have knee pain (of unknown origin).

An analogy: Your elbow hurts. You see me, a learned doctor, and I say, in tones most grave and dignified, that you have “humeroulnar pain syndrome.” You leave my office, distraught, then do some research, and find out that I’ve told you:

You have elbow pain (of unknown origin).

Not too helpful, huh? Same with PFPS.

The second answer is a bit more sophisticated. PFPS does mean “knee pain,” but it does align with a certain set of symptoms (difficulty sitting and walking up and down stairs, for example). So what’s the most likely cause of that symptom set?

In a moment, I’ll offer an, um, “unified theory of chronic knee pain.”

But first, let’s look at chondromalacia in the knee joint. What is that? It’s an abnormal softening of cartilage. That literal definition is rather abstract though. More commonly, it can be thought of as “a condition in which the cartilage ... becomes worn from age or is damaged from injury.”

Now there's one more thing to introduce at this point: patellofemoral pain syndrome and chondromalacia are often used interchangeably. They are NOT the same thing, but the fact that this confusion exists is very interesting. It suggests that one (chondromalacia) may have something to do with the other (PFPS).

Which brings me to a unified theory of chronic knee pain.

Cartilage problems are involved in much of this kind of pain. So bad cartilage would be implicated in many cases of PFPS. What causes bad cartilage, or chondromalacia, in the first place? I doubt there’s a simple answer. It could be anything from an injury to overuse to obesity -- whatever causes wear or damage to the tissue.

Next week: Objections to the unified theory. A response to each objection. Finally, even if bad cartilage isn’t causing your knee pain, why it may not matter in terms of what you need to do to get better.


  1. Hello Richard,

    Thought you would find this article interesting. It seems to go with many of the things you were saying:

    1. Thanks for the link. Yes, some good observations here. It's a pro-prolotherapy site, and I'm curious whether anyone out there has had good experiences with these treatments they'd like to share. I know Doug Kelsey, whom I admire very much, likes prolo. Anyone?

  2. Hi Richard,
    In the time frame 1993-2000, the doctors who saw my condition called it Chondromalacia. None of my doctors (I saw about 3-4 during that time frame) used the PFPS term that i remember. Then I had a period of about 5 years in which I did really well. Then starting in 2006 when I had what I call a major relapse, but this time the doctors called it PFPS.

    So, my point is that perhaps the term PFPS is a relatively more recent term

    But, anyway, thanks for tackling this topic and I look forwarded to hearing your thoughts.

    PS. At this point I have recovered from my Oct 23 setback sufficiently to walk normally without pain. I'm just about ready to start a reattempt at self physical therapy (beyond ice and rest.) for example, start by trying 1-2 minutes on the stationary bike without any tension.... See how that goes. A bit frustrating because as of Oct 13 I had been biking outdoors 13-20 miles including hills!! Why why why having this setback. However, my best guess is that I overdid it on Oct 13 and then continued to aggrevate it during the week ... And More.... Then it reached it last straw.

  3. "
    Exercycle Program

    We feel that this is the single most important part of the rehabilitation program for patellofemoral pain. The idea is to set the bike up so the saddle is a little higher than you would normally like. This limits the amount of knee flexion you are working with. Aim to spin on the bike at a very low resistance (easy) and high cadence (aim of 80-90 revolutions per minute) for 30 minutes. Think 'polishing the knee' rather that getting a big cardiovascular workout. Try to do this everyday if possible. You can increase the resistance as you get comfortable with this. Keep the resistance constant rather than doing repeated intervals of higher intensities."

    1. I like that "polishing the knee" imagery. That's quite similar to what I was thinking when I began gentle cycling as part of my knee recovery program.

    2. Love the "polishing the knee" imagery! Great! Also, this not only emphasizes that you ate not aiming for cardio workout, it also emphasizes that it's not tying to max out the quad. It's just "movement."

      I find watching a movie on my iPhone o listening to an audio book are great ways to help make this boing activity moe fun.

  4. Looking back at my own PFPS I would say lack of knee activity causes it. Specially load bearing activity like walking, squatting, kneeling and forefoot running. Why do some people get it and not others? I think some people are just more prone or delayed in getting it like cancer can be. Our ancestors were on there feet all day long farming, hunting, and foraging. Look at the people that moved out west in wagons which many walked that trip. As a society we are probably the least active than we have ever been in history. Something heals and maintains the knee when moving the knee weather its the synovial fluid or something we have not figured out yet. The studies are out there that prove that activity works. I have a desk job. I have a pretty strong suspicion that caused my PFPS. A tree that is subject to wind is stronger than one that has not.

  5. Wiltser, that is an interesting idea to look into history to see if anyone complained of debilitating knee pain or if this is more a problem in our more sedentary society. I have no idea.

    How are your knees now? Were you able to cure your PFPS?