Saturday, September 24, 2016

If Your Doctor Can’t Figure Out Why Your Knees Hurt ...

You might want to get a bone scan to  look for abnormalities.

The more I watch Dr. Scott F. Dye speak (thanks to TriAgain for yet another link), the more I’m convinced that knowing what's going on with the bone behind the cartilage is often critical to understanding knee pain. That’s what Dye thinks, and he makes a good case.

He attacks a lot of the received wisdom on what causes knee pain. He’s refreshingly unorthodox. For instance: what surgeon hates surgery? But he pretty much does, except for limited instances, and he appears to favor the least amount of surgery possible.

He’s also almost vitriolic in his dislike of structuralists. You know, the dozens of doctors who tell you your problem is because your kneecap is mistracking. I remember my first orthopedic doctor cited this as a reason for my pain, then when I queried him further on the point, he kind of mumbled it away. That’s probably because my kneecaps sat quite normally in their groove on my X-ray. So he probably realized that that standard argument was absurd.

Dye also doesn’t think much of blaming cartilage defects for your pain. On this, I’m not quite convinced – the cartilage does attenuate forces traveling through the joint, and if it’s damaged or missing, well, that seems significant. And Dye himself (through self-experimentation – now that’s dedication!) identified the synovium as being highly innervated, and a possible source of knee pain. So perhaps fragments of damaged cartilage could migrate through the synovial fluid to the synovium, irritating it?

Still, in his defense, he claims to have grade three chondromalacia in one of his knees – and it’s totally asymptomatic. So maybe I’m guilty of overselling the line “heal your cartilage.” Even so, I think my program for getting better would have fit a lot of his criteria for what makes sense for fixing bad knees: go slow, and stay within your “envelope of function.”

Curious about Dr. Dye, and what the heck I’m talking about? Check out these links:

Why You Need to Know About the “Envelope of Function”

What Implications Does “Envelope of Function” Have for Designing a Plan to Beat Knee Pain?

Scott F. Dye on Why Your Knee Pain Diagnosis Stinks (And Why You’re Not Getting Better)

Sunday, September 11, 2016

Decoding What Those Crackly Knees Mean

I found this research study interesting and wanted to share:
Engineers are developing an acoustic knee band equipped with microphones and vibration sensors that can listen and measure sounds inside the joint — and could lead to a way to help orthopedic specialists assess damage after an injury and track recovery progress.
Hmm. Apparently the listening device on the knee band was created by combining microphones with piezoelectric film, which is very sensitive to vibrations. The microphones are placed against the skin.

Of course all knees make noise: pops, creaks, crackling. Often these are benign. But when you have knee pain, they're called "crepitus" and take on a new significance. It turns out, even if the noises are hard to make sense of, there is at least one message in there:

An injured knee makes markedly different sounds than a normal knee. “It’s more erratic,” according to Omer Inan, an assistant professor of electrical and computer engineering at Georgia Tech. “A healthy knee produces a more consistent pattern of noises.”

Inan, in recording the sounds knees make, has encountered challenges. Fluid that surrounds the joint interferes with sound waves, and moving your knees causes its own kind of noise that can drown out other noises that are more important.

As someone who listened hard to his injured knees, I’m interested in what they find. I do think knee sounds are meaningful, but I also think it’s very hard to figure out that meaning.