#486 What is talar beaking on x-ray of a runner? - DOC

#486 What is talar beaking on x-ray of a runner?

What is talar beaking on the X-ray of a runner? Well, that’s what we’re talking about today on the Doc On The Run Podcast.

 

Today’s episode comes from a discussion I had with a runner in person who had some foot pain, it was kind of weird. He’s an elite runner and he started developing this symptom that he couldn’t figure out and it was in a weird spot.

He got an evaluation and part of his evaluation was X-rays of his foot. When we got the X-rays of his foot and we were looking at him, he had this thing that we call talar beaking and he wanted to know what that was. And that’s obviously a weird term, but it is a pretty simple thing.

The talus bone is one of the main bones in your foot. This is the talus here and it sits on top of your heel bone. When you pronate and supinate, it’s really motion at that joint underneath your talus that we call the sub-talar joint because it’s underneath the talus.

Well, when you get talar beaking, what that means is that right here, right on the top of the talus where you have this little, bitty ridge that the cartilage attach to, it actually starts forming excess bone. And so, right there, on the top of the foot right there, you start getting what looks like a little shark fin and it actually points up and over and forward over the navicular bone.

It’s an odd thing to see on the X-ray and it looks like a bone spur and sometimes doctors will say, “Well, you have this own spur on the top of your talus. Maybe that’s causing your pain. Let’s go take it off. Let’s go to the operating room and remove it so it’s not causing pain.”

But that is something that does not often cause pain directly and talar beaking is a classic secondary sign of something called a tarsal coalition and tarsal bones are the bones in the foot. You have the metatarsals, they get stress fractures a lot out here. Then you have the lesser tarsal bones, which are the little ones in your midfoot and the greater tarsal bones are the talus and the calcaneus, the big ones in your rear foot.

The tarsal coalition is just a thing where you get an abnormal union between two bones. When you get that abnormal union, if it causes pain and stress, because your normal biomechanics would allow that motion to happen and it causes stress and strain and discomfort, your body responds by trying to stop any motion that might be painful. And the way that happens is by forming bone around a joint to block and prevent that motion in the joint.

If you start developing a big lump of bone on the top of this joint right here that extends forward over the navicular, it actually stops the motion in the talonavicular joint. When we look at your foot and we think about the talonavicular joint, the naviculocuneiform joint, the met-cuneiform joint and so on, they’re all components of the medial longitudinal arch and the part of your foot that actually helps hold up your arch.

But we know that when you actually fuse just this joint, just the talonavicular joint out of all of these joints, between all the 26 bones in your foot, that when you actually fuse that one joint, it actually blocks 85% of your sub-talar joint motion.

So when we do flat foot reconstructions on patients who have really flat feet and they’re painful, because their tendons are stretched out and stuff, many times doctors will only fuse the talonavicular joint because it stops so much motion that it basically prevents you from collapsing into what we call a flat foot position.

The reason I mention that is that, that really explains why talar beaking happens. If you have this abnormal union or you have something that’s very painful in your foot, even if it’s not a coalition, if you have a cyst in the bone or some damage in one of the joints and you’re running in your training and it causes stress and strain and discomfort, then your body will start to naturally form excess bone near one of those joints that will stop that painful motion.

That’s part of the natural progression of any kind of arthritis is you get excess bone spurring or formation of bone to try to block and stop that painful motion. And that’s really all it is, when you start to get this bone forming on the top of the talus, on the head of the talus that we call talar beaking.

If you have an X-ray and your doctor says, “Well, you have talar beaking,” you definitely want to do something else to assess what is really causing the problem. Is it a tarsal coalition? Is it a cyst within the bone? Is it damage to the cartilage in one of the joints? What is it? Is it post-traumatic arthritis? Why are you getting that problem?

If you just go and take off the bump, you’re not really fixing the problem. You’re just fixing one of the things that happened as a consequence of some other problem. And that hopefully helps you understand a little bit more about what talar beaking can be on your X-ray if you’re a runner.