Old, Bad Beliefs Die Hard

I came across this Internet article on the VMO (vastus medialis oblique), one of the four muscles that, collectively, are known as the quadriceps. About halfway through, I noticed an interesting assertion:

... patellofemoral pain syndrome. A misaligned patella results in pain on the front of the knee, ultimately caused by a weak VMO.

My initial reaction was along the lines of “Whoa, back that truck up!” For one, if you read a lot of the literature on patellofemoral pain syndrome (PFPS) from informed sources (as I’ve tried to do), you’ll discover there’s much confusion about what indeed does cause PFPS. (Actually, to take a step back, it’s not even clear that this is a meaningful diagnosis in the first place.) So this article’s pat suggestion that your knee pain is caused by a misaligned patella that in turn is caused by a weak VMO is venturing way out on a limb.

For starters, the role of a mistracking kneecap in causing pain may have been oversold. This study (rather small but intriguing) found no relationship between the amount of patellar mistracking and reported knee pain.

Then there’s the problem of strengthening the VMO in isolation. That, by implication, is what someone with a weak VMO in this scenario needs to do. After all, if your problem is maltracking, and you strengthen all the muscles equally, then it seems you would have the same amount of maltracking, only with stronger muscles causing it.

So how do you strengthen the VMO in isolation?

Well, you can’t, as Doug Kelsey has observed a number of times, such as in this passage:

The VMO is one of four muscles which all share the same nerve: the femoral nerve. Muscles contract when nerves tell them to contract. Since the VMO has the same nerve as the other three thigh muscles, it will contract along with the others. You cannot make the VMO contract by itself.

Strengthening the VMO to correct a mistracking patella is a typical old school recommendation for treating chronic pain from achy knees. Tease the reasoning apart, bit by bit, and it falls to pieces. Yet the advice lives on in many corners of the Internet.

Of Goats, Noses and Knees

Here’s a novel location to pinch a little cartilage for rejuvenating a worn-out knee joint:

Your nose.

Apparently a study on goats (I know, from weird to weirder) showed that the cells in their noses that make cartilage could perform the same function in their knees.

So now researchers are seeing if they can replicate the results in a human trial. Full results weren’t available when the summary linked above was written, though we were told the patients were doing “extremely well.”

This story somewhat surprised me. I would have guessed that knee and nose cartilage are from two different families, so to speak, and one wouldn’t be able to properly substitute for the other. But looks like I would be wrong. :) In any event, if you have bad (or no) cartilage in your knees, in another 10 or 20 years, doctors may be assessing your schnoz as a potential donor site.

Platelet-Rich Plasma Therapy Wins Some Fans

This article recently caught my eye.

A Utah doctor told assembled colleagues at the annual meeting of the American Society of International Pain Physicians that studies are showing the efficacy of platelet-rich plasma (PRP) therapy for various conditions, including knee osteoarthritis.

Dr. Richard Rosenthal cited for example a paper showing that patients (the subjects were age 45 to 85) had a significantly smaller chance of reinjuring their rotator cuff after a massive tear if they received PRP gel. A different study demonstrated a salutary outcome for lower back pain sufferers.

Caveats are in order of course, as the article notes. PRP is still a relatively young procedure. Issues remain to be sorted out, from the proper protocol for treatment to identification of differences among some 40 products currently on the market.

One voice of caution, Wellington Hsu of Northwestern’s school of medicine, notes that there are “holes in the evidence for PRP in the management of osteochondral lesions and knee osteoarthritis.”

So, expect further studies. The good news is, if PRP continues to shine in clinical trials, insurers may agree to pick up the tab for the procedure -- some $750 per injection -- which (at least in the U.S.) they won’t do now.