So we'll move along to elbow dysplasia. So the takeaway for elbow dysplasia is that this results from asynchronous growth of the radius, the ulna, the humerus, multiple bones. The elbow is a complex joint. There's three bones, they're a weird shape, they have to fit together perfectly. And so if, during development, the shape of the bones do not match one another, then, like we've been talking about, that's going to result in poor congruity. So the bones are not going to fit together well. And that will set them up for inappropriate weight transfer across the joint. And so then that sets them up to be painful to develop articular cartilage damage, to develop progressive DJD. So there are four things that we commonly include in the syndrome of elbow dysplasia. Syndrome is just a collection of abnormalities that tend to present together. So the four things that we'll usually include in the syndrome are ununited anconeal process, fragmented medial coronoid process, or sometimes we'll refer to that is medial compartment disease, medial humeral condylar osteochondrosis, and overt joint incongruity. Again we think that many of these animals have some degree of joint incongruity. But if it's definitive enough that we can identify it on our imaging, often that will be something that we will pull out and kind of mention specifically. Some dogs may only have one component, in which case it's usually medial compartment disease. But many animals will have multiple components present. 

Once again, this tends to be a disease process that affects large and giant breed dogs. You know, your golden's, your labs, your rotty's, all of those friends. They are typically going to present, as you might expect, with signs of elbow arthropathy. So they are painful. They are lame. It can be sometimes a little difficult to evaluate their lameness because they're often bilaterally affected. And then the other thing to kind of keep in mind with the pain and lameness, when they have elbow dysplasia, they'll often hold their limbs kind of abnormally abducted because they're painful. And so they're trying to offload the more painful part of their joint that then puts stresses on their shoulder. And so a lot of times when these dogs come in, they're painful in their elbows and their shoulders. We call them shelbow pain dogs. And that, that pain in the shoulder is just secondary to the abnormal way that they're holding their limbs when they're ambulating. Okay. So pain, lameness, often in the elbow especially, they lay down a lot of periarticular fibrosis to the joint will feel kind of thicker than it should be. And that periarticular fibrosis, as well as the degenerative changes that they tend to get, often leads to, restricted range of motion. So if you flex the elbow of a normal dog, you should be able to really acutely flex it, you know, just like you can your own elbow. And very often dogs with elbow dysplasia, you'll find that you can get them to about 90 degrees and then it's like you hit a brick wall and they can't flex any further than that as a result of all of the change around their joints. And then they'll typically have joint effusion as well. 

Generally when we see animals come in with elbow signs, we'll start with screening radiographs. Because, you know, we can see things like fractures, you know humeral condylar fractures are pretty common. Weird things like radial luxations and all that kind of crazy stuff. But a lot of times our radiographs are more for ruling out other causes than for definitively evaluating this animal for, components of elbow dysplasia. Because unfortunately, a lot of the pathology that we're dealing with for animals with elbow dysplasia is very small. It's very subtle. And so radiographs are actually quite insensitive. If you look at this rad that I have here, this is indicating and, you know, a tiny little fragment that you can make out associated with the, medial coronoid process. You know, that's going to be challenging to see. Like, frankly, the fact that we can see it at all probably means that it's actually a pretty big fragment. Often we can't see this whatsoever on radiographs. And so, you know, radiographs again, mostly we're ruling out other abnormalities. So that we can kind of plan for how best to treat this dog. And then the thing we can see on our radiographs is we can get an idea of how bad are the degenerative changes, because that we can see, we can see osteophytes, you know. And so we can definitely appreciate if the animal has significant elbow arthritis maybe secondary to its original elbow dysplasia. But if we have a relatively clean joint especially, and we don't see things like those tiny, subtle little fragments, very often when they come in to see us, we recommend CT'ing them. And so if we, CT them, that's going to eliminate a lot of those issues with superimposition, which is a big issue with radiographs of the elbow. We can eliminate that superimposition. And we also have better resolution. We can take those tiny, tiny little slices with our CT machine and so we can really see very well these tiny structures that are often affected in animals with elbow dysplasia. That's said, even CT isn't perfect. Some animals, especially like more minimally affected animals, can have pretty normal appearing bones but actually have cartilage damage. And so the gold standard for diagnosis of elbow dysplasia is arthroscopy. And so we can arthroscopically evaluate the joint. This is a picture of actually a human wrist. But you can see that normally the articular cartilage should be nice and smooth and, you know, wide and fairly regular. If you put a probe in alongside your arthroscope, you can palpate it and appreciate that it's, you know, nice and sturdy. And so if we scope the joint of the dog with elbow dysplasia, we might appreciate that there's abnormalities of the articular cartilage. And those unfortunately, we can't see even with CT. So in a perfect world, all dogs with potential elbow dysplasia would get a scope. The other nice thing about arthroscopy is that we can simultaneously, treat these guys while we're in there. 

So we'll go through the individual components of elbow dysplasia and chat a little bit about them. So the one that is easiest to diagnose on radiographs is an ununited anconeal process or UAP. The anconeal process of the ulna, remember is this little like beak of the ulna. The anconeal process should fuze to the rest of the ulna by no later than 20 weeks. In most dogs it should be fuzed by 16 weeks. But German Shepherds again tend to be a little bit delayed compared to other breeds. So we'll give them up to 20 weeks, but certainly by 20 weeks everybody should have fuzed. And so if we are still seeing a persistent, ununited anconeal process in a patient that is greater than 20 weeks of age, that's when we can make that diagnosis. And there is a specific view NAVLE® likes to ask questions about things like that. There is a specific view that will make identification of a subtle ununited anconeal process a little easier. And that is a flexed lateral. So in this bottom picture here, this is a neutral lateral view of the elbow. And you can see that the medial epicondylar ridge superimposes with the anconeal process. I would say in this case we can still see that it is ununited. But if it's subtle, you know, if it's got a fairly small little cleavage line, then you can acutely flex the elbow, really flex it as much as you can, and take another radiograph. And that will help to pick this epicondylar ridge off of the anconeal process and make it more readily apparent. So if we identify this in a very young dog again around that 20 week mark, we can potentially fix this specifically. And so generally what we will do is we will fixate this anconeal process to the rest of the ulna with something like a lag screw. But important to consider, this is probably not unifying with the rest of the ulna because there is underlying joint incongruity. And so simultaneously, a lot of times people will recommend releasing the ulna. So doing what's called an ulnar ostectomy. Removing a little section of it. And that way when the animal is in weight bearing, that weight bearing will be able to kind of push the ulna into the position that it needs to be. So doing those two together gives you your best shot at being able to get this anconeal process to heal to the rest of the ulna. However, if that does not work out or if you identify this in an older patient, you know, once they're older than like 24, 28 weeks, we think that trying to fixate the anconeal process is less likely to be productive, and so in those cases, we can consider fragment removal. But the anconeal process is, you know, it is ideal to keep it there because when the animal is in extension, the anconeal process will lock into the condyle of the humerus, and really helps create a lot of stability. And so if we remove it, we could predispose that animal to joint luxation, which is not ideal. So if we can get it to heal either by doing just an ulnar ostectomy or by more commonly fixating it and doing the ulnar ostectomy, that certainly is ideal. 

Next section is fragmented medial coronoid process. So the coronoid there's a medial and lateral coronoid. I think of them as kind of like the little arms that the ulna have that are like hugging the radius. Essentially the medial coronoid process forms that most medial aspect of the joint. And so in a normal elbow, the weight bearing from the across the elbow joint should be, if anything shifted a little bit more on to the radius. Because remember the radius the radial head has this nice wide area for articulation with the humeral condyle. But over on the, the ulnar side, if the ulna's say a little bit too long, we really just have this little small medial coronoid process. And so if that is shifted a little bit above the radius such that it is articulating, kind of first or primarily with the humeral trochlear, then the concern is that that narrow little region of contact, remember that pressure equals force divided by area, and so if we're concentrating all those pressures from, weight bearing right over that small area, we can overload that medial coronoid process and potentially cause damage to the articular cartilage at a minimum, and then often fragmentation of that little area of bone. So if you see here there's this is a CT image being taken, kind of, you know, slicing through the elbow at a location where we can see the medial coronoid. So this structure right here, that's, wrapped around with the circle, that is the medial coronoid. And you can see that there's been a lot of degeneration. It looks like maybe a little fragments come off here. So this bone is being damaged by seeing these higher than normal pressures. Because of this joint and this underlying subtle joint incongruity. Okay. Like I said, these can be very hard to identify in plain films. CT and arthroscopy are going to be the, much better, much more effective ways at picking up on the fact that there is a FMCP present. Treatment wise, we generally will recommend going in surgically, ideally arthroscopically and removing the fragmented area of bone as well as debriding any damaged cartilage. If there's marked joint incongruity that we can appreciate on our, scope, we can actually remove the entire medial coronoid via a process called the coronoidectomy. And so that should help to shift more of that weight back onto the radial head where it belongs. 

Osteochondrosis, we've been chatting about a little bit already. But when we see it in the elbow, most commonly we see the subchondral bone defect located in this medial humeral condyle. There are often pretty subtle lesions, especially on radiographs. You know that's why I had so many pictures of the humeral head because it's, you know, so much easier to see OCD lesions in the shoulder. In the elbow, you can make out I think this is a really nice radiograph of one. You can make out this like subtle little divot in the subchondral bone of the humeral condyle here. it's easier to see on CT very often. So this is the CT image again showing that there's a defect in the subchondral bone. So that's key. You know that there is actually a bone lesion here. Very commonly if you are scoping elbow joints, in an animal that has a fragmented medial coronoid process, if you look at the humerus directly above the, coronoid, which is the region of the medial humeral condyle, you'll very often see cartilage damage that can look somewhat similar to an OCD lesion. We'll call this a kissing lesion. But the key of a kissing lesion is that the underlying subchondral bone is normal. And so if we have an actual bony defect that is an OCD lesion, not just a kissing lesion. And so in those cases, again, we'll have the same set of options like I talked about when we're talking about OCD, specifically. Palliative options versus much less commonly in the elbow, joint resurfacing. 

And then again, I think pretty much all these lesions are likely due to some degree of joint incongruity, but sometimes it's significant enough that we can see it. So both of these radiographs show pretty marked joint incongruity. So in this case this radius is like way shorter than the rest of the ulna. In this lower picture, it's kind of the opposite. This ulna's way shorter than the head of the radius. And so, generally, if we can appreciate it and, you know, we can actually measure a little step in between the radius and the ulna, and if that's greater than, like, two millimeters, it's likely to be clinically significant. And so that animal may benefit again from something like an ulnar osteotomy or ostectomy, something to allow weight bearing forces to help normalize the difference, the mild difference in height between those two bones. If it's really extreme, potentially we might even need to do, either a radial lengthening or radial shortening. It just depends on exactly what we are, identifying. But most of the time we try to leave the radius intact and just address the ulna because it is, responsible for less of the weight bearing than the then the radius, ideally should be. And then occasionally I feel like this is something I've seen mostly in Basset hounds, occasionally we can also appreciate incongruity between the ulnar notch and the humeral condyle. And so that's just a little bit different, obviously. That is not an area that's quite as important for weight transfer. But it is still important for, you know, normal function of the joint, and changes in the way that the, the ulnar notch and humeral condyle fit together can still be associated with pain, with joint degeneration with signs of elbow dysplasia. 

In general, I would say dogs with elbow dysplasia, especially if it's, you know, pretty severe, I would say that their prognosis is fair at best. Most animals will be more comfortable following surgical treatment, and it just makes sense. You know, if you're walking around with like, a little chronic fracture of your, your coronoid process and we go in and we get rid of that fractured area, you're probably going to feel better. But the joint is never going to be normal again. And so our long term prognosis is going to be limited by progressive osteoarthritis. Again the elbows are relatively unforgiving joint. And so these are the cases where really I would pull out all the stops for management of osteoarthritis. You know this animal needs to be kept lean. these guys might benefit from a joint diet or fish oil supplementation. You know, I like them to stay active, but try and avoid really heavy, like, high impact activities that involve a lot of running and jumping, instead focusing more on, you know, kind of things like slow, controlled, leashed walks or swimming is great. You know, we want to maintain their range of motion. We want to maintain their muscle mass. But they absolutely are going to be, you know, dogs where I prep owners that managing this dog's, arthritis is going to be critical for them lifelong to keep them as comfortable as possible. And then sometimes we only identify these dogs later in life. And by later in life, I probably be like, you know, three, four, not like 12 usually. But sometimes we'll identify these guys when they are, you know, younger to middle aged adults. And unfortunately, in those cases, they often have really significant DJD, you know osteoarthritis already. And so in those cases, surgical therapy unfortunately may not have as much of a benefit as if we were able to get in there a little bit earlier and do something to, to help them, before they developed all of those, secondary changes. All righty.