Friday, August 30, 2013

Chronic Knee Pain: The Great Impostor (and Mystifier)

In the comments section, TriAgain (a regular reader) recently asked me an interesting question. Do I think I might have had “complex regional pain syndrome” when I was struggling with a pair of knees that often burned?

“Complex regional pain syndrome” ... it faintly rang a bell. My curiosity piqued, I looked up this definition:
Complex regional pain syndrome (CRPS) is a chronic pain condition most often affecting one of the limbs (arms, legs, hands, or feet), usually after an injury or trauma to that limb.  CRPS is believed to be caused by damage to, or malfunction of, the peripheral and central nervous systems.
Yeah, but what are the symptoms, I wondered. So I read on:
The key symptom is prolonged pain that may be constant and, in some people, extremely uncomfortable or severe. The pain may feel like a burning or “pins and needles” sensation ... The pain may spread to include the entire arm or leg, even though the precipitating injury might have been only to a finger or toe. Pain can sometimes even travel to the opposite extremity.
Okay, with you so far. Then I hit this section:
People with CRPS also experience constant or intermittent changes in temperature, skin color, and swelling of the affected limb ... The skin on the affected limb may change color, becoming blotchy, blue, purple, pale, or red.

Other common features of CRPS include:
* changes in skin texture on the affected area; it may appear shiny and thin
* abnormal sweating pattern in the affected area or surrounding areas
* changes in nail and hair growth patterns
* stiffness in affected joints
* problems coordinating muscle movement, with decreased ability to move the affected body part, and
* abnormal movement in the affected limb, most often fixed abnormal posture (called dystonia) but also tremors in or jerking of the affected limb.
Uh, nope. Pretty sure I didn’t have that.

So why did I describe TriAgain’s question as “interesting” if this syndrome appears to have no relevance to my former condition? Because I know exactly what’s he’s going through.

When I had knee pain all the time, I Google’d everything under the sun, trying to figure out what was going on with me. I skimmed articles about conditions with long Swedish names that contained funny-looking vowels. I even had a blood test for rheumatoid arthritis (which I passed with flying colors), as a I recount in my book.

Why so much confusion about a pair of damaged joints?

Here’s my best guess as to what happens with a lot of chronic knee pain patients (note: of course some may have complex regional pain syndrome, or rheumatoid arthritis -- or some other condition -- as their primary problem; I don’t mean to discount that possibility).

You start out by having simple knee pain, but as time goes on -- and as your body enters a long-term inflammatory state -- you notice other problems that seem more systemic, or not related to your original localized pain, and you discover your knees seem sensitive to non-physical stressors, such as emotional stress or depression.

Okay, I’m kind of spitballing here, making a guess based on my own experience and personal accounts I’ve read by others. But it seems this progression, from basic knee pain to something more elusive and insidious, is not uncommon.

Now, what if this is indeed true? What if many of us suffer from bad knees + something systemic that is weird and hard to figure out? (note: again, this assumes that the systemic stuff isn’t your main problem -- e.g., you don’t have a disease like rheumatoid arthritis). What to do?

Well, I’m not sure what you can do about the systemic issues or even what they are exactly. However, fixing the damaged knees -- that (once again) I think requires a long, slow program of gradually increasing load on the joints.

My best guess is that, if you fix the bad knees, the weird systemic stuff (the nettlesome “ghost in the machine”) will go away, at least in most cases. It did for me anyway!


  1. Well, here's something interesting. Went to my
    GP today. Told him the whole story of the past 16mths & he agreed my symptoms do actually correlate with CPRS (now called RDS - Regional Dystrophy Syndrome), though compared to many suffers, my symptoms are quite minor.

    RDS follows an initial injury (or surgery), where the sympathetic nervous system goes haywire & sends pain signals to the brain which are in excess of the damage in the knee (or other limb).

    A few other things about RDS:

    *Icing makes it worse (even though it might make it feel better) because it damages the myelin sheath around the nerves. I iced the Hell out of my knees in the years before the chronic pain started....there's a clue!
    *Immobilising the joint makes it worse.
    *Passive motion machines are often used to mobilse the joint and help the condition.
    *Due to the lack of physical damage on x-rays etc, sufferers are often labelled as hypochondriacs (my tri coach suggested as much).

    So Richard, perhaps you & I had/have a minor form of RDS.

    Moreover, my GP fully agrees with you that knee cartilage can definitely heal - he cited the case of a German woman who was told she needed knee replacements, but instead started running very very slowly and now runs ultra-marathons!

    cheers, TriAgain

  2. I'm still very doubtful I had this syndrome. My symptoms don't really match well at all. Plus, I definitely had some sort of damage in the joint -- my knees made a terrible crackling, and I could hear a ripping sound when I stood up from a deep squat. The damage to the cartilage didn't look bad on my MRI, but my belief is that my knees were on the verge of falling apart fast, but I acted quickly enough to prevent that -- and had I not, and gone in for a second MRI a year or so later, the results would have been much different.

    Anyway, whether RDS or PFPS or chondromalacia -- sounds like a similar program helps, if your doc says immobilization is bad and CPM machines are good. Easy motion ... it's a winner.

  3. Yes, my knees also make some ugly noises coming out of a deep squat. I avoid them like the plague.

    My Doc also ordered some basic knee X-rays (because apparently RDS can cause bone deterioration). However, the unofficial word from my OS (who just happened to be the guy at the hospital who reviewed them) was that they looked really good, very little sign of osteoarthritis....but I don't believe straight X-rays tell you much about the cartilage, other than perhaps it's thickness.

    But here's the worrying Doc has got me doing very shallow (not to the point of pain) single leg squats, and has asked me to try running (well, slow shuffling for 5 mins) again. His theory is that with RDS, you need to re-train the muscle proprioception and the nerves (and there is a Norwegian study to support this). Of course the danger is if it is not RDS, it might send me backwards. Stay tuned!

    cheers, Triagain

    1. Definitely, keep me updated. It'll be interesting to see if the new exercises help or hurt.

  4. Wow, Tri, that is a surprising diagnosis. Please keep us updated!

    As for me, after returning from vacation, I realized that my knee was a bit irritated after doing TOO much walking during my vacation: all those museums and palaces and basically walking walking walking all day every day seeing the sites. But, once I got home and was doing less walking, my knee seemed happier! It was happy to do SOME walking for sure, but, not as much as I had been doing on vacation.

    What I've been doing lately is "living life" rather than embarking on a focused knee-healing campaign. For me, this means I've not been doing knee-healing-specific exercises, but, I've just been making sure to incorporate walking into my daily life. For example, instead of taking the bus the full distance to work, I get off early and walk .5 miles to the office. I often take about 1 one mile walk at lunchtime, and then I walk at least part of the way home, so, 1 - 2 miles. So, each day I'm getting in about 3-4 miles of walking, but not all at once! It's spread out over the day.

    What I've found is that this seems to be agreeing with my knees and everything seems to feel calmed down.

    THUS, just about now I feel that my knee are in a good enough state for the next stage which will be (slowly!) starting up my water therapy again and some light joint-friendly activities -- the same way that I had "healed" myself last summer year, except this year I will be MORE CAREFUL and I will not get fooled into thinking "I'm healed" when I actually still need to just keep on the slow and steady program of careful incremental increases in activity.


    1. I don't think it is a firm diagnosis Knee-pain, but it is something he's not ruling out. I forgot to say as well as shallow knee bends & trying to shuffle-run, he's put me on glucosamine-chondriton with MSM, but the powdered form not the capsules (he swears by it). Again, the jury is out on that supplement, but I'm happy to give it a try. I think he's having a bit of a punt three ways - doing things that can assist RDS, also doing some of the old muscle strengthening & joint nutrition stuff and also doing stuff that will be good for my head (resume running). Not exactly a controlled experiment, but I know enough now to monitor it all like a hawk & stop anything that seems to be sending me backwards.

      I still reckon the one form of 'movement' that my knees always seem to benefit from is gently wandering about & regularly stopping to stand fly or lure fishing for a few hours. Just as long as I don't crouch down on scramble up and down any steep banks. But is it the gentle movement or is it because it really takes my mind off my knees...or is it perhaps the cool water settling the inflammation? Who knows?

      cheers, TriAgain