Using an Ultrasound to Diagnose Foot Pain

"Today we’re going to talk about use of an ultrasound machine in diagnosing and treating certain conditions. The beauty of an ultrasound machine is as opposed to an x-ray that just shows us a two-dimensional video of the bones and the alignment of the foot and ankle, an ultrasound is a live imaging, so I can see the bones but also the ligaments and the tendons and when we move those structures, we can see the exact areas where they might be inflamed or sore. So it helps us diagnose sprains and strains and tears right here in the office.

Have you ever had an ultrasound performed before? No, okay. So it’s an interesting technology, such that out of the probe here, we see a small amount - a small sound wave comes through the probe and it penetrates into the structures of the foot.

That sound wave is going to bounce off from various structures in the foot, based on how thick they are or how dense they are, and then come back to the probe. What we see on the screen is the reflection of the sound waves. Very much the way a radar gun works. 

When we’re able to see that, we can see areas of fluid versus hard areas like bone and we can tell if there’s any inflammation in there. In a lot of conditions, like plantar fasciitis or achilles tendonitis or even in stress fractures or neuromas, we’ll be able to see that increased size or the thickness caused by the inflammation and some of the fluid surrounding it.

Let’s take a look at your left foot plantar fasciitis, and again, ‘itis’ at the end of any word means inflammation, so we’re looking at the left foot plantar fascial band. An ultrasound is non-painful, so we do not feel any heat emitted or any pain on that area. When we look at the screen here, I will freeze it for a moment and show you exactly what we’re looking at. That’s the beauty of an ultrasound. You can actually see some of those structures in the foot that don’t get picked up on an x-ray. When we look at this screen, to orient yourself, the back of your heel is here, and the bottom of your foot is on the top of the screen. Essentially, your foot is sitting like this, the toes are up this way. Do you see this white ridge extending right here? It comes down in a sloping pattern - that’s the bottom of your heel bone. As you can see, everything underneath there is dark, because the ultrasound cannot penetrate through the bone. Like we talked about, that plantar fascial band stems right off the heel bone and runs along the plantar aspect of the foot. Do you see this wavy structure coursing through there? That’s your plantar fascial band. If we measure it, coming right off of the heel bone, we can see that we’re measuring about 4.2 millimeters. That shows us that there is some inflammation, because the normal plantar fascial band runs about 3 millimeters of thickness.

As we are able to trace that further out we can see that there is a decrease in the inflammation and back to our normal size. The beauty of having this in the office is not only will it show us and give us an exact diagnosis, but it shows me exactly where that condition is the worst. It’s diagnostic, but if we needed to do an injection into there, we could localize right on the spot that’s the most inflamed through visualization under the ultrasound. 

The other nice thing is that we can continue to check on that fascial band if we need to, to ensure that we’re making progress as we treat this."