Wellness Wednesday: All About Condylar Fractures

Mary Phelps pays extra attention to her 3 rockstars to keep them in peak performance and notices any signs of lameness (Photo: Picsofyou.com)

Lou Barton: There’s a topic that’s on everyone’s mind: Mastery, of course, one of the favorites on the derby trail, a possible contender. Certainly, Jimmy Barnes, assistant to Bob Baffert, said he was a horse to watch. We met him at the Breeder's Cup Classic last year. Lovely horse. Sadly, he had to have surgery this past Monday for a Condylar Fracture. When Jimmy texted me he said he was absolutely gutted...he didn't see it coming. I don’t think you can really see those things coming, and I know Jimmy, being the horseman that he is, if there were any signs he certainly would have noticed. So, Dr. Lynch, tell us what a condylar fracture is.
Dr. Lynch: A Condylar Fracture is a fracture of the condyle or the distal end of the front or hind cannon bone. It’s usually to either one side of the center of the leg, at the bottom of the cannon bone. They can be of different configurations...they can be medial and complete, meaning they go up the medial side of the leg and they break out. Or they are incomplete and they go up through the medial side of the leg or even the lateral side and they don’t break out and you just see the lines. The bone responds to the pressures applied to it, meaning the bone will remodel and through training will try to heal itself or make it stronger. The problem is that the healing and the repair process falls behind the training and the pressure applied to it. So now it's out of balance. As far as healing the bone, of course when you run at high speeds, the bone will undergo some strain, stress and some microfractures, and then it needs to heal to get stronger so it can take the next training bout. Unfortunately, most of condylar fractures are due to repetitive bone strain or repetitive bone trauma. They either take a bad step or they load it beyond its mechanical abilities and they fracture through that weak spot.

Lou Barton: Now is this most typical or likely to happen in a younger horse?
Dr. Lynch: I think it’s when most of them happen, but it can happen to any horse. Meaning that it can be a racehorse, or a jumping horse, it’s typical of either...the bone not being able to keep up with the training schedule. The bone only needs so many cycles to get strong; it doesn’t need any more cycles than what is really necessary. Younger horses are still more prone to it because they’re still growing. So it's kind of a mixture of all sorts of things, it could be the horse itself, the training, the surface, the cumulative distance that the horse has trained - - things like that lead up to a condylar fracture.

Lou Barton: Are there any signs or any symptoms that you can look for? In the case of Mastery, he ran the entire race, the San Felipe, he won it beautifully! Actually right after the finish line and Mike Smith who is an absolutely incredible jockey noticed something immediately, felt like a bad step...and he pulled the horse right up immediately and jumped off. And they said that it probably saved the horse's life, had he gone on and finished cooling off that possibly the horse might have had to be put down. Is this something that can happen suddenly like that?
Dr. Lynch: Absolutely, the signs to watch are certainly lameness and that's what everybody watches for. There could be heat, pain and swelling in the fetlock joint and typically it's not a super lameness initially, like this horse that pulled up, he ran the whole race, and they pulled him up at the end. It's one of those things; it can all of a sudden be an acute injury.

Lou Barton: Can you talk a little bit about the surgery and what the possible outcome of that is. We were just discussing recovery, this horse Mastery, just came out of surgery very well and is going to have 90 days of rest. Are the chances pretty good that the horse will be able to at least do something in the future and possibly even race?
Dr. Lynch: So that's, all dependent on the fracture itself, there's a lot of energy that's released when they break a bone. This joint unfortunately suffers the most damage, the articular cartilage. So if there's just one piece, and you put it together with screws, some of them require plate and screws. But if the joint is relatively unharmed and it’s clean and the bone heals perfectly or back together with the joint surface being pretty even or flush. A lot of these horses can come back and race and they can have other careers, hunt, jump, event, and those types of things. Its arthritis eventually that holds them back. If the joint really does suffer a lot of damage and the cartilage is now damaged beyond any repair, they’ll become an arthritic horse over time. But a lot of them depending on the fracture, they are saved for breeding; like a stallion or broodmare, but others...the whole point of fixing them is to make them a comfortable horse and if they can do athletics after that, it would be great.

Lou Barton: We very much hope that Mastery can come back and race again, but whatever is best for him is what will happen in that barn. But really it was sad, he was my favorite for the Derby. Is there anything else Dr. Lynch that you want to share with us about this condition?
Dr. Lynch: Well, there are many ways to try to diagnose them before they happen. There are a lot of racing jurisdictions are thinking of putting in pre-race MRI’s, and that is still a debatable thing. Other ways to find them are bone scans, you have to use radioisotope to identify a crack of the newly formed bone because you can’t see it on a plain radiograph, and it’s a difficult thing. It can sneak up on you and then you have this terrible accident. So being careful paying attention to the horse, paying attention to the lameness, heat, pains, swelling, changes to the horse's legs are certainly the hallmark of good horsemanship and how to head those things off.