Is there an echo in here? Didn’t I have another item about this just recently? I did indeed: on July 8 I shared news that glucosamine made no difference for back pain patients, and here we are again with yet another F-grade for glucosamine, this time for knee pain (which is the problem that most people take the stuff for). If glucosamine were a student, its parents would get called in for a conference about little glucosamine’s poor performance. Perhaps there’s something going on at home? This is how the latest report card reads:

Over 2 years, no treatment [neither glucosamine nor chondroitin sulphate] achieved a clinically important difference in [knee] pain or function as compared with placebo.

(The conventional pain-killer celecoxib did not have any effect either.)

The pile of glucosamine failures is now getting rather tall. This morning Dr. Harriet Hall reviewed the evidence of absence of any glucosamine benefits in more detail at ScienceBasedMedicine.org and concludes that glucosamine proponents

… can always complain that maybe it works for knees but not for hips, or that a different dosage might have worked better, or that it works for some small sub-set of patients. There will always be “one more study” to do. … This new study confirms my opinion that we shouldn’t spend any more research dollars doing “one more study” on glucosamine.

Here’s the references for both of glucosamine’s recent epic fails:

• Sawitzke et al. Clinical efficacy and safety of glucosamine, chondroitin sulphate, their combination, celecoxib or placebo taken to treat osteoarthritis of the knee: 2-year results from GAIT. Ann Rheum Dis. 2010.
• Wilkens et al. Effect of Glucosamine on Pain-Related Disability in Patients With Chronic Low Back Pain and Degenerative Lumbar Osteoarthritis: A Randomized Controlled Trial. Journal of the American Medical Association. 2010.

Not that this evidence will actually stop people from “believing” in glucosamine and buying it in bulk! Glucosamine bottlers will really appreciate everyone’s continued gullibility.

Recently a reader wrote to me to point out that, in his opinion, recent scientific evidence has begun to support the “conventional wisdom” about chronic anterior knee pain (a.k.a. patellofemoral pain syndrome, or PFPS). That would make my e-book on the topic look bad. I pretty much roll my eyes at the conventional wisdom from the first word to the last.

I would be delighted to be wrong. Being wrong is good. I have an ego, but it’s invested in my intellectual integrity, not the position I held in 2009. (Just this Monday I cheerfully admitted some major wrongness about icing and heating therapy.)

So I went looking for recent papers that might embarrass me.

Super quick review of the conventional wisdom

The conventional wisdom is that PFPS is caused by biomechanical dysfunctions, and that they can be treated primarily with therapeutic exercise. The classic example: in patellar tracking syndrome, the kneecap slides unevenly, allegedly placing greater strain on the knee, which thus leads to pain; but the tracking problem can be fixed by selectively strengthening one side of the quadriceps muscle group.

My wisdom is that the conventional wisdom has resoundingly failed to help patients. Biomechanical problems are real but minor factors and largely untreatable in any case, and the characteristically stubborn character of PFPS is mainly due to a simple but vicious cycle: knees are extremely difficult anatomical structures to rest, with or without minor biomechanical dysfunctions, and once they have been aggravated by over-use they simply have a hard time calming down.

Correlations, schmorrelations

The paper the reader cited was “Concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain”, which I was already familiar with. It didn’t change my mind before, and it still doesn’t.

Yes, Boling presented some data in 2009 showing a modest association between PFPS and hip weakness, but it was hardly a smoking gun! The weakness could be either a symptom of knee pain and/or a cause of it. Having a painful knee probably has an impact on how you use your whole leg, and might well cause hip weakness. The literature is overflowing with studies like this, and they collectively produce no clear signal. This one doesn’t change the basic (confused) picture, and they continue to be blatantly contradicted by other studies. For instance …

One of the recent studies that I found when I went looking states that “factors related to physical impairments did not associate to function or pain.” They present a long list of the usual biomechanical suspects, including hip strength just like the Bolgla, but they found no correlation at all with chronic anterior knee pain.

(Interestingly, they did find that “psychologic factors were the only associates of function and pain in patients with PFPS.” Now that’s odd, isn’t it? I’ll have to write an article just about that!)

Not-so-conventional conventional wisdom

Here’s another interesting point: Boling doesn’t particularly support “the conventional wisdom,” but rather a new variation on it. Their evidence (vaguely, weakly) suggests that it’s all in the hips. They found “weakness in eccentric hip abduction and hip external rotation.” This is certainly conventional wisdom in spirit (i.e. some biomechanical problem is to blame). But it’s also a whole new biomechanical bogeyman, not one of the usual suspects. This new fascination with hip function is a bit of a fad, an attempt to replace the old usual suspects. Many authors are claiming that there is an “emerging body of evidence” that hip function is critical to knee health. Bollocks. This is highly debatable, especially because most of that alleged “body of evidence” is emerging from one researcher’s public relations efforts: he loves doing press conferences and interviews for glossy running mags, but has yet to actually produce any evidence that any kind of runner’s knee pain is caused by hip weakness. I have criticized the hip strength thing quite strongly and thoroughly.

If the hip-weakness hypothesis is eventually proven — which is possible, despite my objections — it will result in therapists prescribing something new (hip exercises), and not something old (quadriceps exercises). That would really be validation of the conventional wisdom. But I’m not holding my breath.

Gait retraining results are significantly insignificant. Or something.

Also in the not-so-conventional wisdom category is “gait retraining.” If PFPS is all in the hips, then maybe learning to walk again will help your knees? A brand-spanking new study, not even in print yet, offers the closest thing I found to a surprising clash with my previous beliefs. I would not have expected these results:

Gait retraining in individuals with PFPS resulted in a significant improvement of hip mechanics that was associated with a reduction in pain and improvements in function.

Sounds straightforward and good, and they have my attention.

On the down side, the abstract is painfully vague (and buying the whole article would be a bit expensive), and I suspect some hanky panky. In particular, I’m troubled by the fact that their findings about two of their three “variables of interest” were not found to be statistically significant (which they admit), and then they don’t mention the third! Translation: “We measured three important things, and two of measurements were not stastically significant.” And the third? “No comment.”

But then they conclude with “significant improvement of hip mechanics!” What gives? Eh? What was significant?

They don’t say.

Another red flag is the curious statement (very unusual for an abstract) that one measure of improvement was “very close to significant.” This is an abuse of statistics. That phrasing tries to put a positive spin on bad news: there was actually a fairly high chance that the result was just a coincidence. It’s kind of bad form to say “almost” statistically significant instead of “not” statistically significant. I do not think that this word “significant” means what they think it means!

All of this pretty much reeks of researchers who really wanted a pro-gait-training result, and they did some mental gymnastics to make it sound like they got it.

Perception of knee pain is everything

Another experiment which had the potential to make me wrong was a comparison of “supervised exercise” versus “usual care.” I would never recommend supervised exercise, which is very much in the conventional wisdom camp, and a total waste of time in my opinion. But, at first glance, this paper looks like it’s displaying a fat thumbs up for supervised exercise: “Supervised exercise therapy improved patients’ pain at rest and during activity, and self-reported function improved faster than with no supervised intervention.”

Wow! Goody gumpdrops! Get me some supervised exercise for my knee pain, stat!

But wait, read the next sentence:

“The patients’ perception of recovery from patellofemoral pain syndrome was not greater among the supervised exercise group.” My emphasis.

Er … what? “Perception of recovery”? “Not greater”? Isn’t that kind of, um, a total letdown?

You bet it is! Simply put, you can measure as many “functional” improvements as you like, and while it might be interesting to the lads in lab coats, it doesn’t matter a tinker’s damn to the patient if they aren’t improved enough to feel better. You can’t say that a treatment “works” when the patient doesn’t perceive recovery. Basically what these patients said was “sure, maybe it’s better in a couple ways, but basically I still have a @!&^$% frustrating case of knee pain.” Patients who can’t preceive recovery regard the therapy as total bollocks.

So in some ways this study showed that (supervised) exercise is good for PFPS. But mostly it showed that it doesn’t do anything that matters. And when you consider the cost of hiring a physical therapist to supervise your exercise …!

Conclusion

Nope, my face is not red. I do not feel embarrassed by my anti-conventional-wisdom position on patellofemoral pain syndrome. It’s not time to change my mind on this yet. And, of course, even if I did change my mind I wouldn’t actually be embarrassed by it.

Perhaps of note is that the polite, constructive criticism that inspired all of this has not amounted to much. A reader raised a concern, but cited only a single example of relevant science (the Boling), and has not responded to my request for additional examples. This is what I would call a “hit and run” criticism: a perfectly good criticism in spirit, but where’s the beef?

But I still took it seriously. I always respond to such criticisms with an earnest spasm of self-doubt: what if I’m wrong? What if I’m publishing something incorrect? It was a good exercise to go trolling through the recent research looking for evidence that I might be wrong about knee pain.

Alas, not this time.

References

• Boling et al. Concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. Journal of Athletic Training. 2009.
• Hart. Supervised exercise versus usual care for patellofemoral pain syndrome. Clin J Sport Med. 2010.
• Noehren et al. The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. British Journal of Sports Medicine. 2010.
• Piva et al. Associates of physical function and pain in patients with patellofemoral pain syndrome. Archives of Physical Medicine & Rehabilitation. 2009.

Corticosteroids are hormones that are produced by your adrenalin glands. (Not adrenalin itself — that comes from another part of the adrenal glands, and it’s a catecholamine. Quiz later!) Broadly speaking, these hormones suppress immune function, dancing and balancing constantly and intricately with other hormones that stimulate immune function. And inflammation is a product of the immune system, so corticosteroids have a nearly miraculous effect on inflammation, pretty much nuking it wherever the two meet. But like nukes, they have a dark side: some harsh side effects. You can’t just willy-nilly soak your system in corticosteroids without paying a price. Many readers may have heard of the many unpleasant effects of the common corticosteroid, prednisone.

Targeted injections, on the other hand, are quite a bit safer. The small amounts of corticosteroids involved are just not enough to be a problem for the whole system. And so steroid injections are a handy way of delivering a potent anti-inflammatory effect right to the source of the problem — think of them as ibuprofen on, er, steroids.

This can work great when you know where the source of the problem is. The evidence showing that they work well for targetable inflammation is acceptable, and one injection is often enough in the case of iliotibial band syndrome (see Noble, Gunter) where the target is fairly clear and accessible, where the target is fairly clear and accessible. Unfortunately, this is precisely what is often not known about PFPS. Where do you put the stuff?

There is no research at all about the effectiveness of steroid injections for PFPS, and no wonder: there’s too many possible injection sites, too much uncertainty. Corticosteroid injections are usually suggested only by doctors who don’t really know what else to do, and think it might be “worth a shot.” Does that physician know where to put the needle? Probably not.

I’m all in favour of using steroid injections when there is a reasonably good reason to believe that you can target an inflamed tissue. But the problem with recalcitrant PFPS is that you almost never know what tissue the pain is coming from — and in many cases it’s deep inside the knee — so where do you inject?  It becomes not so much a shot in your knee as a shot in the dark, with risk factors.  I’m not completely opposed to it in dire cases where nearly anything is worth trying, but it’s a weak option at best.

There’s no harm in discussing it, but ask your physician for his or her thoughts on the location of the injection and the reasons for it, and be skeptical if there isn’t a healthy respect shown for the uncertainties. If you do try injections, and three of them do not pretty clearly do the trick, you should probably stop trying, as steroid injections can permanently damage connective tissues near the point of injection. For this reason, some doctors will refuse to do it at all, but most agree that 1–3 injections is no cause for concern.

• why injuries go bad
• how to temporarily destroy your nerve endings with chili pepper (and why this is a good thing)
• the pain of being a drama queen

“Bio-psychosocial determinants of persistent pain 6 months after non-life-threatening acute orthopaedic trauma”

Clay et al. Journal of Pain. Volume 11, Number 5, p420-30. May 2010.

How often does injury lead to chronic pain? Why do some injured people develop chronic pain and others do not? Researchers kept tabs on 168 patients who suffered non-life-threatening orthopaedic injuries.

54% reported persistent pain six months after the injury and 87% reported that this pain interfered with their normal work activities.

Long-term pain was more likely to the extent that pain was acute at the beginning (independently of injury severity), if patients felt responsible for the injury, and if they were pessimistic or emotionally traumatized. “Psychosocial factors strongly predicted persistent pain, pain-related work disability, and pain severity,” the researchers concluded, and noted that “many of these factors are potentially modifiable and should alert the clinician about the need for interventions in order to prevent the development of pain chronicity.”

“A Randomized, Controlled, Open-Label Study of the Long-Term Effects of NGX-4010, a High-Concentration Capsaicin Patch, on Epidermal Nerve Fiber Density and Sensory Function in Healthy Volunteers”

Kennedy et al. Journal of Pain. Volume 11, Number 6, p579-587. Jun 2010.

Ever wish you could get rid of some nerve endings? It turns out that you can — just apply chili peppers! This experiment showed that nerve endings shrivel away from an application of capsaicin, the active ingredient in peppers. The effect was quite dramatic.

Healthy volunteers took one for the team: a single application of highly concentrated capsaicin on their thighs, for just one hour. The density of nerve endings and sensitivity to various stimuli was recorded before and after, and then checked again after 1 and 12 and 24 weeks. The results were amazing: nerve ending density was down 80% after a week, and pain sensitivity was also reduced (though much less). Touch sensitivity reduced slightly, and heat and cold sensation remained normal.

Over the next several weeks, the nerves regenerated and sensation returned to normal. Given this surprisingly potent effect on nerve endings, capsaicin may be an effective and safe way to treat some pain problems.

“Emotional Regulation and Acute Pain Perception in Women”

Ruiz-Aranda et al. Journal of Pain. Volume 11, Number 6, p564-569. Jun 2010.

This experiment presents clear evidence that “pain is an opinion”: an experience modified by mental and emotional factors.

I don’t think anyone will be surprised to learn that being a drama queen actually hurts. (“Drama queens,” of course, is exaggeration for comedic effect — please don’t actually call anyone in pain a drama queen unless you want to get smacked around.)

Two groups of women were tested for pain tolerance with the traditional, unpleasant method: immersion of the hands in ice water. One group was rated with better emotional coping skills, and (predictably) they were more tolerant of pain than women with poorer coping skills.

Although the results seem unsurprising, the authors say that “currently there are no experimental investigations of the relation between emotional regulation and pain.” Based on this study, it can be assumed that emotional state and skills are relevant to pain management.

People out there in on the interwebs often write to scold me for this — how dare I criticize writing when there’s a tipo off my own on the very same page? Why don’t I just stick to the idees?

Of course, whenever I make criticasms of sloppy writing, I do open myself up to a charge of hypocrazy, because there are certainly scattered errrs on my website, probbly even on this veru page. But it’s a matter of dagree. I only criticize someone’s communiation skills when their writeing problem are signicifant and revelant : when the errors are thick and nasty and thick and nasty, when they arre combimed with style problems like SHOUTING IN CAPS!!!, or abusing “quotion marks”; or just horrible spellung and grammer and sentense structure, and and whn they betray ignoranse of the subjet matter,, like a chiropracor who writes the “veterbra” three times in the same short email but incests “I’m a proffesional”.

(I’m not making that last bit up. I actually got that message.)

Not everyone’s a writer, but writing that bad is much worse than just lacking a knack — and it exposes a lack of mental rigour and maturity. There is such a thing as a minimum literacy required for one’s ideas to be taken srsly.

Patients with great anxiety, pain and frustration are especially vulnerable to persuasion, or “therapy by charisma.” This is why I really make an effort in my work to be reassuring without offering miracles, to be knowledgeable without claiming to “know” what the problem is. All too often, patients in pain will cling to whatever ideas you throw at them… so you have to be careful what you throw at them! Structuralists rarely seem to show such restraint, and consequently many patients emerge from therapy feeling much too sure of their diagnosis. There is no zealot like a convert! In this context, clinicians can be more like clergy than health care professionals.

Your Back Is Not “Out” and Your Leg Length is Fine: The story of the obsession with crookedness in the physical therapies

Once again I will be travelling to Las Vegas this summer to participate in “TAM” — The Amazing Meeting, a critical thinking and (who are we kidding) geek convention. I went to my first TAM last year, and wrote a bizarrely long and cheeky account of the experience that was strangely popular. This year I am particularly looking forward to, roughly in order of importance:

• Beers with like-minded friends from around the world.
• The blisteringly dry canned air in the hotel that will relentlessly rip into my mucus membranes. Oops, this is the positive list …
• Richard Dawkins (I’m a huge fan) of God Delusion fame
• Adam Savage (I’m a huge fan) of MythBusters fame (dude is awesome: listen to his great interview with Desiree Schell of Skeptically Speaking)
• Simon Singh (I’m a huge fan) of giving a legal whuppin’ to litigous chiropractors fame

But the main professional attraction is the science-based medicine workshops, presented by the the team of doctors that created the Science-Based Medicine blog, especially Dr. Steven Novella, Dr. David Gorski, and Dr. Harriet Hall. I have had a working relationship with SBM since I met them all last summer, and I volunteer my time doing some copyediting for SBM. If I were to rename my website, I would probably call it Science-Based something or other.

Extremely concise SBM primer

“Science-based” medicine is a conceptual upgrade to “evidence-based medicine” (EBM) that emphasizes that ideas in health care must make a reasonable amount of sense and clearly pass fair scientific tests before we take them seriously. For more information, see Why Science-Based Instead of Evidence-Based?

I am excited about SBM as a movement because I see a dire need for its sensibilities in health care and health information. I predicted that SBM — the idea and the blog — would become a big deal, and I was right. It’s really taking off, and I’m really proud to be involved. It will really be a treat to meet with the SBM writers at TAM8!

So what a happy coincidence that Dr. Harriet Hall, the The SkepDoc, recently let me know that my new article about Traumeel (homeopathic arnica) had come up in fifth place on a Google search for Traumeel. Today it’s second only to traumeel.com, well ahead of any other critical review, and indeed the only listing that isn’t promoting Traumeel. That’s a search engine home run, and it happened practically overnight: only a handful of my articles have ever gotten such a strong showing on a major search term. Traumeel is the world’s most popular homeopathic product, so the search volume is huge.

As people set out to learn more about Traumeel this week, a great many of them will find and read my heavily-researched article. In the months and years to come, it will be seen by tens of thousands of people, and probably continue to be the most prominent source of information available about Traumeel. Even more remarkable is that there’s a strong possibility that SaveYourself.ca supporter can push it to the top of the search listings — or least ensure it keeps a hold on spot #2 — simply by linking to it. Since that goal is in reach, I’d like to encourage anyone with a website to link, link, link. Here’s the permalink for copying and pasting:

http://SaveYourself.ca/traumeel

Does Traumeel Work? A detailed review of Traumeel®, a homeopathic remedy (not herbal) widely used for muscular pain, joint pain, sports injuries, bruising, and post-surgical inflammation

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Are weak hips a major factor in running injuries like IT band syndrome? It’s unlikely, despite the gushing of running magazines over the theory.

From time to time I like to point out that hype about hip strengthening — it will save your knees, it will find your lost socks! — continues unabated in the absence of any respectable evidence. In December, Running Times uncritically reported on Dr. Reed Ferber’s opinions, confidently declaring the very precise alleged mechanisms by which hip weakness does its dirty work (every bit of which is speculation), saying definitely that “this is when misdiagnosis often occurs” (as if hip weakness isn’t a dubious diagnosis itself), and concluding that “Ferber drives the point home.”

No, he doesn’t. Dr. Ferber’s public pronouncements continue to champion the theory by making too much of scanty evidence, and it’s still just another theory in a long series of theories about the One True Cause of running injuries. Nothing has changed. No compelling new evidence has been published. But the hype machine is still churning this stuff out.

Not that I expect quality science journalism from running magazines, but this is the kind of language that results in the exasperating and constant churning of “the truth” in science. Patients and media consumers are bombarded with so-called “conclusions” … which are then inevitably replaced next month because there was never really enough data to say anything with confidence in the first place.

Does Hip Strengthening Work for IT Band Syndrome? Despite its popularity, “weak hips” is a weak theory, and there is no compelling evidence that hip strengthening can treat or prevent running overuse injuries of leg

Between 1992 and 2006, seventeen hundred dancers were evaluated at a dance medicine clinic; only 24 of them had stress fractures (quite low), and conservative therapy had failed in only 7 cases. Those dancers were operated on: their fractures were stabilized with “drilling and bone grafting or intramedullary nailing” — good old carpentry-style surgery! They did well — shins that had previously refused to knit finally knitted. Recovery was slow but steady in all cases, and they were all dancing normally again by about the six-month mark.

“Surgical treatment of refractory tibial stress fractures in elite dancers: a case series”