What’s the difference between a sesamoid fracture non-union and a disrupted bipartite sesamoid sprain? Well, that’s what we’re talking about today on the Doc On The Run Podcast.
I recently got a great question from someone who was watching one of the videos I did on sesamoid fractures and if you’re not sure what that means, underneath your foot at the ball of foot, underneath the big toe joint, you have two little bones that are called sesamoid bones. And let me draw a picture real quick.
Basically, underneath your metatarsal bones, you have two bones that are kind of like the equivalent of tiny little kneecaps. They are sitting right here and sometimes you can get a fracture where the bone is broken. There’s a crack in the bone and if it doesn’t heal, well then it turns into what we call a non-union.
A non-union is just where the bone has not healed. By the same token, you can have a different thing entirely, which is called a bipartite sesamoid meaning that the two growth centers in that bone never actually fused together, never heal together completely. And so when you get a fracture non-union where that’s not healed, you have pain because the bone never healed together and the two pieces of fracture actually moving or rubbing against each other causing pain.
When you have a bipartite sesamoid, they’re not actually sitting there completely individually, but they’re connected by fiber strands of collagen or scar tissue and if you sprained that, if you actually get what’s the equivalent of a sesamoid fracture, but it’s really that you didn’t break either of the bones, you didn’t crack either the two pieces of bone but you sort of tore and disrupted the soft tissue in between. Well, that’s what I call a bipartite sesamoid sprain or a disruption of a bipartite sesamoid.
It can hurt the same way. So, are they different? Yes. That might actually be easier to heal in many circumstances, but they can feel the same and sometimes it’s very difficult for your doctor to tell just by looking at your X ray, which one’s actually bothering you. One of them is bone that never heal, the other soft tissue between two solid bones that’s actually disrupted and causing pain, like a sprained ligament.
Hopefully you found this helpful. If you did, please like it, please subscribe, please share the channel with a runner who needs to hear it and I’ll see you in the next training.