All right, everyone, welcome to our session. We have our annual installment of Musculoskeletal ... Fundamentals of Musculoskeletal Radiology, and this year we will be talking all about the elbow. We have a great panel with us today, so I hope you all enjoy. I have no financial disclosures. Oh, just to introduce myself, I'm Jen Suhu, I'm one of the sports medicine attendings at Cornell, and the sports fellowship director, and I will be today's moderator. Just to give you an outline of what we will be going over in today's session, we'll be first going over elbow x-ray, then some elbow ultrasound, elbow MRI, and then any remaining time for a good Q&A. This is our fantastic panel here, so first we will be talking about elbow x-ray will be Dr. Katie Bartolo. She's an assistant professor in the Department of PM&R at the University of North Carolina School of Medicine. The next talking about elbow ultrasound, we have Dr. Zachary Bailowitz, who is a sports medicine physician at Kaiser Permanente. He also serves as head team physician for Cal State East Bay, and is also the director of the ultrasound curriculum for the UCSF Primary Care Sports Med Fellowship. As happens with post-COVID, we unfortunately were going to have Dr. Martin Lazarus, who is a clinical associate professor of radiology at North Shore University, and director of the Musculoskeletal Radiology Fellowship, and team physician for the Chicago Bears, but unfortunately he got COVID and was not able to join us in person today. However, he has very nicely taped his presentation, so we're going to play a video of his presentation. He is unfortunately not able to join us for questions today, but hopefully ... He's a really great teacher, so hopefully his presentation on elbow MRI will be something that has no questions at the end. All right. So then I'm going to turn it over to Dr. Bartolo to get us started here. Just give us a little 30 seconds to switch in between. All right. Good morning, everyone. So, to start off this session, we're going to be going over elbow x-rays. A little bit of a disclaimer here. It's not intended to be a comprehensive session on interpretation of elbow x-rays, much more intended to be the basics, fundamentals of things that you should be able to recognize and interpret on the elbow x-ray, once again, like a foundation. I'm going to do my best with a pointer to point things out when it's behind me, so let me know if I'm not pointing in the right spot. Okay. No relevant disclosures. So our objectives for today. Radiographs are often the first thing you're obtaining when a patient presents with an elbow complaint, especially if they report a history of a trauma, which is why it's important to be familiar with elbow radiographs. So we'll review commonly obtained views when getting x-rays of the elbow. We will also look into normal anatomy and the skeletally mature and skeletally immature elbow. Particularly for the skeletally immature elbow, we'll be reviewing the secondary ossification centers that are present around the elbow. These are really important to recognize, and so you don't over-call them as pathology. We will also be reviewing different techniques for assessing bony alignment, particularly the anterior humeral line and the radiocapitellar line. And finally, I've peppered in common elbow pathology throughout the talk while reviewing the things that I just mentioned. So starting off with the commonly ordered views, your two workhorse views when getting elbow x-rays are going to be your AP, or anterior-posterior view, and the lateral view. And then one that I sometimes get as a secondary view if I'm more concerned for radial head fractures or pathology, which we'll go into more, is going to be the external oblique. So starting with the AP view, so when you're obtaining this, the patient is seated. They're usually seated for most elbow x-rays. They're going to have their arm extended out like this in full elbow extension with the forearm in supination. And then you're going to have the beam passing anterior-posteriorly and obtaining the view that you see here on the side of the screen. So this is going to be your best view for visualization of the medial and lateral epicondyles. They're going to be in profile, so you're going to be able to look if there are any enthesiophytes or things like that. It's also going to be a good view for assessing the radiocapitellar joint, although we'll get into how there's a slightly better view with that external oblique. And additionally, it's going to be a view in which we can look for any radial head dislocations. So this is an example here. So I've got the one side of the screen where we're going to look at the articulations, which I've highlighted here. So there's the three bones that make up the elbow, really basic anatomy, but I feel like we should be all on the same page. So we've got our, let me see if I can, there we go. So humerus, and then we've got our radius here, and then we've got our ulna here. And so there's going to be articulations between all three of these bones. So we're going to have the radiocapitellar joint, or the humeral radial joint, where the humerus is meeting with the radius. We've got the humeral ulnar joint, also called the ulnar humeral joint, over here. And lastly, there's an articulation of the radius and the ulna, creating the proximal ulnar radial joint. So then over here, we look at all the different aspects of the AP view, and so you can look at all of those, but the main ones I wanted to point out here are recognizing the capitellum over here, and how small it is compared to the trochlea over here. We've got the coronoid at this aspect here, which is the articulation of the ulna with the distal humerus. What's interesting in this view, too, is to recognize how the electron process and the electron fossa look, because they are basically going on top of them, so it's really not a good view for assessing this aspect of the elbow. And then, another thing I wanted to point out here is also the lateral and the medial supracondylar ridge. These will be important when we talk about fractures, as the supracondylar fracture is the most common elbow fracture in general, and especially in the pediatric population. So it is important to be aware of that bony landmark. Next view will be our lateral view. This is obtained, once again, seated. You're going to have your shoulder in abduction, anywhere between 80 to 90, depending on your shoulder range of motion that your patient can achieve. Sometimes people are also going to have shoulder pathology in addition to their elbow pathology, so you have to be cognizant of that. So we're going to have it here in abduction. We're going to have our forearm in neutral with the thumb up. Then we're going to have the medial aspect of the forearm and the palm against the table, and the projection going like that way. And so this is going to be with our elbow at 90 degrees of flexion. So this is going to be our best view for looking at supracondylar fractures. This is going to get into one of our lines for assessing bony anatomy and bony alignment later in the talk. It is also great for identifying occult fractures for that reason. We can look for radial head dislocations in this view. We can look at four in any view. More on that later. And it's also a great visualization of the radio, sorry, the humeral ulnar joint, as well as the coronoid process, which you can see in right here, and also visualization of the olecranon process. It's right there. So what's important to check is that you've actually obtained a true lateral view. So sometimes it'll be slightly rotated, and then a lot of our assessments can give us false negatives, especially when we're looking for occult fractures. So they call this the hourglass sign or the figure of eight sign. And so you're looking at the anterior coronoid fossa, the posterior olecranon fossa, and that is creating this hourglass sign. And you want to also look to see that this looks symmetric here as this figure of eight. If it's not a true lateral view, you really should be obtaining an additional view and should not be obtaining the bony alignment assessments we will talk about shortly. So reviewing normal anatomy here, we went over a few of them just a minute ago. But just doing here, I have a color-coded diagram as well here. And the key thing is being able to recognize there's a lot of superimposition in this view. So being able to recognize the trochlea and differentiating it from the capitellum. So it's that pink compared to the light blue. And also being able to recognize the coronoid, which is in yellow, and differentiating that from the radial head in green. And here we can see that our humeral ulnar joint is highlighted in yellow and that this is a nice clear view in a really young patient, 16-year-old who doesn't have any evidence of osteoarthritis. So also in the lateral view is going to be a great opportunity to evaluate for soft tissue signs, specifically for elbow effusions. So we've got two fat pads in the elbow that are really pertinent when looking for pathology in the lateral view. We have an anterior fat pad and a posterior fat pad. So that anterior fat pad is going to look like a radiolucent shadow. The anterior portion of the distal humerus, I'm going to highlight it here for you in green so you can see it and then take that away so you can try and see it when it's not highlighted. It's a little hard to see if you're really far away. So we'll see it here in green and then take that away. So the anterior fat pad can be normal if it's looking like this, if it's parallel with the distal humerus. The problem arises when it starts to look more like a sailboat sail and it starts bowing out and that's when it's problematic because it's being lifted up and that signifies that there is an intraarticular joint effusion and that can be suggestive of an occult fracture. So if we turn to the right picture here, I'm going to highlight the, here, once again highlighting them in light blue is going to be the sail sign at the anterior part of the humerus. So right here if you can't see it and you can see that shape that it's looking like that sailboat sail. So this is going to be abnormal. Whereas the posterior fat pad sign, if you see that posterior fat pad at all, it's automatically abnormal. Definitely means that there's something going on there. It can't ever be normal. And so the posterior fat pad is going to be the yellow located posteriorly here. And this is important because a lot of times in the elbow, because of the superimposition of all of the bony articulations and the bony prominences, you don't want to miss an occult fracture. And so if you see these, you have to think fracture and you should be looking to either obtain additional views or more advanced imaging such as MRI or a CAT scan. And in different populations, you want to think of different fractures. So in the pediatric population, as I mentioned before, that supercondylar fracture is going to be the most common. And in the adult or skeletally mature patient, it's going to be more of the radial head fracture. One other view that is commonly obtained, maybe not quite as commonly, but still a pretty good view is going to be the external oblique view. This is going to give you a better view of that radial head and that radial neck, better assessment if you have a concern for a fracture, especially for an intra-articular fracture of the radial head. So you can notice here I've included, I've included here, this is that external oblique and you can see here the radial head and the radial neck looking quite clear and there's no superimposition with the ulna over here. But if we look at the AP view, you can see there's a lot of overlap happening here and we might miss a fracture at that location. So for this view, it's very similar to the AP view. When you're going to obtain it, patient seated again, just like all the other views, and your elbows fully extended like this, the difference will be that you will then have the entire arm externally rotated in this degree here, so you're moving that radial head over, so it's getting a nice clear picture. And so now I've moved it over, so now this is going to be our normal. And here I have a picture right there, you can see that there is that radial head fracture and interarticular radial head fracture. So now to talk about pediatric elbow and the skeletally immature elbow. It's really important to be aware of the differences here because fractures, particularly in pediatric patients, can lead to chronic pain, deformities, loss of function in the joint, as well as neurologic compromise. And 10% of all fractures in general are found in the pediatric population. Elbow fractures of the pediatric population, let me rephrase that, pediatric elbow fractures represent 10% of all fractures, there we go. And so the most common being the supracondylar fracture. And so we want to be able to recognize the six secondary ossification centers that are present in the skeletally immature elbows, so we're not over-calling pathology when there isn't pathology, but also being able to recognize when there is a problem or a fracture and not chalking it up to being a growth plate. So there's a mnemonic that has been developed to help us both remember all six of those ossification centers and help us remember the general predicted pattern of their appearance. So it is CRITO, and so when you're remembering this mnemonic, it's important to remember too that they call the medial and the lateral epicondyles, the external and internal epicondyles, because we don't really refer to them like that very often, so you just want to remember that and then you'll be able to use this mnemonic very well. So we have the capitellum is going to appear first, then the radius, then the internal slash medial epicondyle, then we've got our trochlea, the olecranon, and finally the external or lateral epicondyle. So why is this important? This is important because they tend to arrive at certain ages. So roughly the capitellum should ossify at about one year. There is a little bit of variability there, but at least certainly by two years. And the general rule of thumb is you think about one year for the capitellum and that every subsequent ossification center will tend to arrive or appear at about two years after. So you've got like one year, three years, five years old, seven, nine, and then 11. This is valuable because say you have like a seven-year-old coming in and you notice there is a like ossification or bony ossification density at the lateral epicondyle. And you think, oh, okay, maybe that's a secondary ossification center, but there are seven, so they shouldn't have an ossification center at the lateral epicondyle at that point. So that should definitely raise your suspicion there's something going on there and I need to look into this further. These will then fuse starting at about age 14 and then go on into late, in the late teen years. The last ossification center to fuse is going to be the medial epicondyle. This is really important to note, especially in our sports and athletes, our sports players and athletes is because especially our throwing players that as a result, the medial epicondyle is going to be the weakest portion of the elbow in the skeletally immature patient. That's especially true as they get stronger and then you've got a throwing athlete who's especially pitchers, they're putting a lot of strain through that area and be much more prone to pathology in this region. And so I've shown a picture here just to help you get familiar with what this would look like. They're highlighted, so it's easier to differentiate. One thing I do want to draw your attention to is that the trochlea does tend to look fragmented just at baseline, so you really have to be diligent when evaluating and not over calling a fracture there. Sometimes it's helpful to obtain a contralateral view if you're really not sure. We don't do that by convention, obviously, because it's increasing radiation exposure to a pediatric patient, but sometimes getting that contralateral view can be valuable because they should be symmetric. So talking about alignment, there are two important assessments we can do on an x-ray to evaluate the alignment of the bones in the elbow. First one's going to be the radiocapitellar line. This one's pretty cool because you can get it on every single view. It's not just one view. All the views, it should be helpful. So how we do this is we're going to draw the line through the radius, and then we're going to see how it intersects the capitellum. So the key here, if you look at a lot of papers, originally people were saying, well, it should go through the radial neck, it should go through the radial shaft, and then there were a lot of issues with that because depending on development, sometimes there could be an angulation to the radial neck. So instead, a lot of papers have started to suggest that we basically intersect the middle portion of the radial head. So if you look at here, right, so we've got that yellow line going through, the red is highlighting the capitellum, and we're seeing that this is intersecting the capitellum. You don't need to overthink it for the radiocapitellar line. As long as it's in a meaningful way intersecting the capitellum, good enough. Abnormal would be that it's not intersecting the capitellum, and this would be suggestive of a radial head dislocation. I'm just demonstrating here that we've got our two views, right? We've got our lateral view here and our AP view here, and it's still intersecting the capitellum the way it's supposed to, and this is normal. So I've collected a couple options here, a couple examples here of radial head dislocation in both skeletally mature and immature patients. It can happen in adults too. And so you can see here that we've got our capitellum here. This is the ossification center and hasn't fused yet because it's a pediatric patient. And you can see that this radiocapitellar line is intersecting the distal aspect of the humerus, but not the capitellum. So this is positive abnormal, suggestive of a radial head dislocation. And here is in a skeletally mature patient, capitellum is down here, and it's once again intersecting more at the distal humerus. Finally, the anterior humeral line is going to be helpful for us to assess for a supracondylar fractures. This is especially helpful in nondisplaced fractures that might be more subtle that you wouldn't necessarily see when looking at the cortex or other ways that we, uh, we diagnose fractures on x-ray. So this is going to be obtained by drawing a line along the anterior cortex and seeing all the way through to the ulna, and we want it to intersect the middle third of the capitellum. So different from the radiocapitellar line where I said, as long as it's meaningfully intersecting that capitellum, we're good. This one, it actually matters what part of the capitellum it's intersecting. It's that middle third. So on this picture here, that yellow line is going to be the anterior humeral line. The dashed pink lines are going to be separating the capitellum into those three thirds. And then the blue line is representing the capitellum. And we can see that this yellow line, even though it's not in the middle of the middle third, it's still in the middle third. So it counts, and this is normal. So, um, if it was abnormal, then we have to be concerned that there's a supracondylar fracture. Why is this? So usually these are Fuchs injuries. So someone falling on an outstretched arm with the elbow in extension. As a result, it causes the impaction of the capitellum, um, uh, into, I'm sorry, of the radial head, um, the corona or the coronoid, but usually the radial head into the distal aspect of the humerus and will cause displacement of the distal aspect of the humerus. And that's the capitellum. And so that will be posteriorly so that anterior line won't pass through it anymore because it's posterior to where it should be. Important to note that this can only be obtained on the lateral view. So once again, different from radial capitellar line, you could do that on any view of the elbow whatsoever, and it should be helpful. This anterior humeral line, it's only helpful on the lateral view. Additionally, this can sometimes be normally abnormal in children under four. Excuse me. I need a drink of water. Okay. And so just giving our abnormal examples here, normal is on the left side of the screen. And then here I've showed two examples, um, in a pediatric patient with the capitellum highlighted in the dotted white line. And we can see, even though I didn't do the dotted pink lines here to help you out, that this is passing through the anterior portion. I mean, it's very clearly in the anterior first third here and here. Thank you for your attention. And then we're going to move on to ultrasound, everyone's favorite, with Dr. Bailowitz. Good morning. Um, first of all, Dr. Bartolo, that was awesome. Uh, that was supposed to be a basics lecture and you really went into a lot of detail. So well done. Um, my name is Zach Bailowitz. Uh, it's really nice to see faces. Um, I feel like most of the lectures I've given lately, I have this on and some basketball shorts. So it's, uh, nice to see people. Um, yeah, so we're gonna be talking about basics of, uh, ultrasound today. Um, similar to what Dr. Bartolo mentioned, you know, this is not a comprehensive review of, of all of elbow ultrasound. Um, there are plenty of great resources online through AAPMNR and AMSSM that, that go through this stuff in a lot of detail. And, you know, we've got 20 minutes, so I'm going to try to get through some basic stuff, uh, show some pathology and, uh, uh, certainly welcome to have questions at the end. Um, I have no disclosures. Um, so today, uh, goals, we're going to discuss the basic protocols for all four anatomic regions. I'm going to demonstrate some examples of pathology. Uh, really I'm going to try to highlight the utility of the dynamic exam because I think especially in the elbow that becomes valuable. Um, and then briefly discuss, uh, report writing. Um, so a lot of this is going to be based on, um, a few of these resources that AIUM in 2017 put out their practice parameters. Um, and, and that's a valuable resource, I think for a couple of reasons. It really highlights the things that we should be trying to view, uh, in each body region, but also, um, it is important for billing as well. So those of you that are actually performing diagnostic exams and billing them, um, you need to take a look at what they require. Excuse me. Um, The AMSSM in 2021, I believe, put out their sports medicine ultrasound curriculum recommendations. So this is not exactly the same as what's necessary for billing, but is a nice outline as well. And specifically the sports ultrasound scanning protocols that they highlighted are going to be what I'm going to kind of talk about today. So again, the elbow, every joint in the body, except the shoulders broken up into four regions, anterior, posterior, medial, and lateral. You know, a lot of this, if you can, let's see if this works, here we go. A lot of this as indicated, you'll see that. And that's because not every examination requires each of these structures. The as indicated is sort of, you know, just what it says, as indicated based on the pathology that you might be expecting or where the location is of their pain. But this is typically the kind of stuff that I like to follow. You certainly need to have a joint, a tendon, and a ligament in each of your exams. And then a lot of what I think we can provide, and I was hoping that Dr. Lazarus would be here, because I think a lot of the contrast here is valuable, but a lot of what we can provide actually is the dynamic exam and then evaluations of nerves. And so I'm typically scanning a decent amount of nerve pathology. And you can see in each of the regions there are nerves listed. One thing you'll also see is that there are some areas, like for example, the ulnar nerve, which is listed posterior, but also listed on the medial exam. And so these structures are not mutually exclusive. This is something that, you know, depending again on where the pathology is, you may do a posterior exam, but you might shove a little medial in there just because of where they're hurting. And so don't be afraid to overlap, but just making sure that you're checking at least some of the basic boxes. Now, again, Dr. Lazarus is not here to defend himself, so we get to all kind of beat up on him while he's not here. But, you know, advantages and disadvantages, right? So ultrasound, I think, again, a big thing. This is a dynamic exam. And especially around the elbow, there are a lot of dynamic pathologies. People come in with snappings and gappings and all these fun things. And we can really get a good evaluation of that with the ultrasound. As we know, it's portable. So whether that means a training room or whether that means, you know, going to a remote clinic where you don't have an ultrasound otherwise, it's inexpensive in real time. And patients, you know, as we all know, patients love, you know, what is that? No, that's the baby. And they love that joke and all that. Nerve visualization, again, we talked about that. And then, you know, this concept of provider-dependent is something that I struggle with a little bit because certainly experience with ultrasound is provider-dependent. The more hands-on time you have, the better you're going to become. But that implies that MRI is not provider-dependent, which, of course, we know is not true. We see radiology reports that might say something different from what another radiologist said or from what something that we see. And I miss stuff that the radiology catches, and they miss stuff that I catch. And so, you know, MRIs are just as provider-dependent as ultrasound, and it takes time to look at an MRI just like it takes time to look at an ultrasound. Now, MRI is great for looking at intra-articular structures. We don't have that ability with ultrasound. And bony pathology, especially things like bony edema, so looking for stress fractures and things like that, that's certainly an advantage of MRI. And I think the biggest thing is it's just more familiar to our surgical colleagues. You know, a lot of them are just more comfortable looking at MRI. And so, this is something that will continue to be a struggle until we can sort of get its comfort with some of our providers. And I've noticed that some of the newer, my surgical colleagues that I work with, they seem to be more comfortable with ultrasound. And so, you know, the hope is that that continues to progress. I just wanted to highlight this paper. This just came out. This is, you know, just a few months ago. But this big group from Europe, they put out this six-part dynamic ultrasound protocol for each body region. And the elbow one is amazing. There's these really, really cool diagrams. But if you go online and you actually look at this paper, they have all these videos of all these different pathologies that you can see dynamically. It's a really, really cool resource. And so, from a dynamic standpoint, definitely something to take a look at. So, we'll start my protocol. I tried to do some color coding of boxes here. So, blue, blue, green, green. Okay. We're comfortable with that. Oh, we got a mouse. Oh, thank you. Oh, sorry. Can you go back one slide? Thank you. Oh, yeah. Perfect. So, this is the kind of axial view of the elbow. This is sort of your home base. And the first thing that we see is we've got the trochlea and the capitellum here, and the articular cartilage, which lives over the top. The brachialis muscle is this sort of big thing here that takes up the majority of the screen, and usually not something that's all too often pathologic. The biceps tendon in cross-section sits up here. And then, again, a lot of what I'm looking at is nerves. And so, we've got the radial nerve here. And you can see it's already started to split the superficial and deep branches. And then, the median nerve lives here. In the kind of more sagittal view or long axis view of the joint, we see here the radial head and then the capitellum with the articular cartilage over the top. You can see a fat pad here. And this is a nice correlate to what Dr. Bartolo was speaking about earlier. This is a nice place where you might see a potential sale sign where that fat pad is lifted up. And you can see an anechoic or hypoechoic region of fluid here. And so, this is something where you might be able to identify a fracture, let's say a radial head fracture that was not picked up on the x-ray for whatever reason. And maybe you don't see the actual fracture on the ultrasound, but you see this sale sign and you know you need additional imaging or additional views. So, here... And sorry, I should have said this from the beginning. All of these normal, quote-unquote, pictures are my elbow. So, please excuse, like, the mild degenerative changes that you see in there. I thought I was going to get some good, nice, normal images, and it turns out I have some stuff. So, apologies. So, this is my distal biceps tendon. It's supposed to be nice and linear throughout. I do have a little bit of tendinosis here. So, apologies for that. But this image is taken through what's called the pronator window. And so, you start with your ultrasound just right in line with the humerus. And then, keeping it in line with the humerus, you kind of track it down a little bit till you get to about here. And that gives you this nice view of the biceps tendon coming down, attaching onto the radial tuberosity. Now, this is a tricky image to obtain, because not only do you have to stay in this weird kind of funky plane, but you also have to do a fair bit of heel towing. And so, this video shows that you're kind of... If you don't heel toe, you don't get those nice linear fibers. So, you can see how anechoic it is there, and then you heel toe and you get nice linear fibers. And so, that's an important technique when you're looking at that pronator window. Now, here I am on the medial elbow talking about an anterior structure. Why am I doing that here? Well, the biceps tendon lives anteriorly when you're on the anterior elbow. I actually look at this most when I'm doing my lateral elbow scans, because I think that there's a lot of mimics of tennis elbow with biceps tendon pathology. And so, just because you're looking on the medial side doesn't mean you can't include this in your anterior or your lateral exam. Here's just some examples of pathology. This is a patient that has a history of psoriatic arthritis, and you can see not only some biceps tendinopathy, but some fluid surrounding the biceps tendon in that pronator window view. And then, if we watch the video here, you can see starting in that anterior elbow view, there's that big area of kind of anechoic or hypochoic fluid. So, this was a biceps tendinopathy and biceps tenosynovitis. This case was a really interesting one, pretty much complete tear, but only of one of the two heads as it attaches down onto the radial tuberosity. So, this was a long head rupture. You can see the anechoic cleft right here indicating fluid. But if we look at this video, there certainly was some tendon that was, while tendinopathic, still intact. And so, understanding that you can get these kind of complete but partial ruptures of the distal biceps, he still was able to flex. He didn't have that kind of hook sign, and we ended up treating him without surgery. And so, this was a helpful piece of data for us. Again, I talked a lot about nerves. So, in the anterior elbow, we look at the median nerve. I usually, again, track it down from that anterior elbow view. Here, you can see it sitting just adjacent to the biceps tendon. We've got a cross-sectional area of about nine millimeters squared. But as I go distally, it really gets flattened and smushed right in here. This is deep to the pronator teres with a cross-sectional area of four millimeters squared. And so, if we watch the video here, you can see the nerve here. It comes down, looks fairly normal, and then right there, it gets very, very smushed. And so, this is an example of a patient with pronator syndrome, which I don't see too often, but I thought this was a really nice example of it and something to, you know, we think about this with our EMGs. And those of you that are doing EMGs, you know, I don't think I had any cases of pronator syndrome in my residency with an EMG. So, I thought this was a unique case. Okay. So, moving on. So, we're at the lateral elbow now. This is going to be your sort of typical lateral elbow view. Here, we've got the common extensor tendon coming over the top. And then, the radial collateral ligament lives in this sort of bottom 50 to, or 30 to 50 percent of the footprint is this radial collateral ligament. But you can see that they really do blend together. And oftentimes, it can be difficult to distinguish both in a normal patient and in a patient with pathology as well. The radial collateral ligament kind of comes over the top and eventually blends in with the annular ligament, which kind of surrounds the radial head. And that gives you your lateral collateral ligament complex. One thing to keep in mind is that we should still be looking at the joint in this view. I get a lot of patients referred for tennis elbow, and they've got some some degenerative changes of their elbow joint. And we do a diagnostic injection into the elbow joint, and they get good resolution of symptoms. And so, not every patient with lateral elbow pain is tennis elbow. And I'm going to say that about six more times throughout the talk, because there's other examples of that as well. When I first started doing a lot of this lateral elbow scanning, I wasn't getting this short axis view very often. But I've started to realize how valuable it is. Dr. Schrader, I don't know if she's here, she put out this cool paper a couple of years ago that really helps to sort of break apart the common extensor tendon into the various tendons that actually make it up. And you could see, for example, that there's this small little hypo-echoic area sitting in the ECU. And so, what that tells us perhaps is that, oh, this patient has some ECU pathology, or they're overusing this kind of ulnar deviation. And can that direct our physical therapy? Can that direct our trigger point injections? Can that direct our PRP or whatever it is that we're doing? So, this cross-sectional view or this short axis view actually is quite valuable. And I would encourage you all to spend some time kind of deciphering those areas. I didn't put any pathology of tennis elbow on here intentionally. I'm sure most of you have seen that. Sorry. Thank you for telling me. My apologies. So, I didn't put any examples of tennis elbow common extensor tendon pathology because I think we have all seen that quite a bit. But this is a nice example of a relatively normal common extensor tendon with this small hypo-echoic cleft right here, which is a sort of example of a radiocollateral ligament partial tear. Here, you can see there's quite a big anechoic cleft. And so, this is an example of a full thickness tear of the radiocollateral ligament, while the common extensor tendon again remains intact. And on a dynamic exam, again, you can see that gapping of the joint. If we can play that one one more time possibly. Yeah. So, you've got the gapping of the joint here with the anechoic fluid here. And again, that dynamic exam shows how gapping that gets. So, this is a valuable thing when you're examining these patients. And again, not thinking that all of these patients are going to come in just with your tennis elbow. Um, the last thing that I look at on the lateral elbow is going to be the radial nerve. And so, as we know, the radial nerve starts off more proximally. It splits into the superficial and deep branches and becomes the posterior interosseous nerve as it dives through the supinator here. And so, this is a typical view that I'll obtain. You can see it sitting here just at the entrance to the supinator called the arcata-frosch. And we see it sort of sitting here. It usually looks relatively flattened. Occasionally, you will see it look like this. And this is a nice example of what's called supinator syndrome where the radial nerve or the deep radial nerve is getting entrapped. And I do like to follow it down all the way from the distal aspect of the upper arm because there's a vessel that sits under here. And that's what's called the leash of Henry, the recurrent radial artery. And occasionally, that vessel can loop over the top and cause some irritation or entrapment of the radial nerve as well. Are you guys hearing me better? Okay. Thank you for pointing that out. My apologies. So, we'll move on now to the medial elbow. This is the common flexor tendon. It's quite a bit different from the common extensor tendon, much shorter, stubbier tendon. It doesn't have that broad attachment onto the sort of ski slope that we see. And it's a slightly different orientation from the collateral ligament, whereas on the lateral elbow, we can see the lateral extension and we can see the lateral collateral ligament at the same time as the tendon. So, here you really need to change your views slightly. So, here we've got our common flexor tendon orientation and then we move on to the common flexor orientation. Then we move on to our UCL orientation here. And so, here's a nice example of the UCL coming across and attaching right there onto the proximal aspect of the ulna there, sublime tubercle. There's been a lot of papers describing UCL evaluation with ultrasound. This was a nice example of some pathology, a patient I saw last year. You can see that the proximal aspect of the ligament is not here. It kind of ends right there. And then on the dynamic exam, we see a nice large gapping of the joint. And so, this was a patient that had a full thickness UCL tear. There's quite a bit of literature discussing the various ultrasound techniques and the different measurements that we should be considering. I think the consensus right now is probably 1.5 millimeters in terms of gapping, but I certainly think there are other papers that talk about two millimeters. And then there are some papers that talk about using a comparison. So, comparing from one side to the other. And so, you know, certainly if you have a patient where you're not quite sure if this is a full thickness tear, definitely compare to your other side. I think that the standard right now is one millimeter difference from side to side. And then the last thing on the medial elbow is, of course, the ulnar nerve. So, we typically see the ulnar nerve sitting here between the medial epicondyle and the olecranon. It's typically in kind of this orientation here. And again, starting to scan it above and below the elbow is important here. I'm starting distal to proximal. So, you can see it sitting here under the flexor carpi ulnaris. And as you go proximally, you'll see it sit in that groove there. And then you can continue to go proximally there up into the distal medial arm. Those of us that are doing EMGs, there is some data to suggest that the ultrasound exam is actually correlative. And so, this paper showed that we can actually break apart mild, moderate, and severe ulnar neuropathy based on cross-sectional area in addition to using the nerve conduction study. And so, this is something I'm measuring quite a bit, especially if patients have kind of mild to moderate symptoms. Unfortunately, our wait times right now for our EMGs are long. So, I'm oftentimes getting patients before they've had the EMG and I've found that for the most part I'm relatively good at being able to predict the severity of their conduction block on the EMG. So, it's been a neat thing to add to the practice. Clearly, this patient has a very enlarged ulnar nerve, 33 millimeters squared. So, this was a patient that was diabetic with severe ulnar neuropathy. But the reason I put this up here is because check out this thing. That's just a big vein. So, don't confuse the two of them. Make sure you track this down and make sure it's not compressible. Here's this nice longitudinal view. You can see more proximally the nerve is relatively normal in size. Sorry, more distally the nerve is relatively normal in size. But you can see it's quite thick and proximally and then you get to the entrapment site right here. I've had a couple of my hand surgeons start to send me these ulnar nerve patients after they've already had an ulnar nerve transposition. So, most of the time the surgeons I work with are doing submuscular transposition. So, they're taking the nerve, putting it under the flexor bundle. And this patient was presenting with ulnar neuropathy. They had already had a transposition a couple years ago. And we were able to show not only that the ulnar nerve was a bit flattened here, but that the common flexor tendon actually had some calcific tendinopathy. And so, this was a neat case to be able to say to the hand surgeon, hey, the reason that this ulnar nerve is so pissed off is that their common flexor tendon is irritated. And so, they were able to then go in and change the orientation. They ended up doing a subdermal. That's not what it's called. Underneath the skin, that's where they put the nerve. And then they were able to actually do a common flexor tendon repair at the same time. And so, this patient had some good improvement from that. Here's a nice video. Again, watching the nerve looks relatively normal, but then you saw it slip under that tendinopathic region there. One thing I do see a fair bit during my ulnar nerve scans is the presence of an anchoneous epitrochlearis. And so, you know, this is a little accessory muscle that lives here that can put pressure on the ulnar nerve. So, obviously, scanning both sides to see if it exists on both sides. And don't mistake this for the medial head of the triceps because the medial head of the triceps can come down into that retrocondylar groove there. But if this is there, oftentimes it can cause compression. And this is something that's relatively easy for the hand surgeons to release. The last thing is the dynamic exam. I've harped on this a couple times and this is, I think, really important. I'll play the video in a second, but this is an example of an ulnar nerve that subluxes up and over. But not every subluxing thing in the medial elbow is as an ulnar nerve. There's also subluxing or snapping triceps. And so, this is an example of the triceps tendon, that medial head of the triceps. And you can see it snap down right over the epicondyle there. And then on this video here, we see the ulnar nerve kind of snapping all the way up and over the epicondyle. So, again, the dynamic view coming into play. One of the important things about this is that you can't put too much transducer pressure. If you do, you're going to limit the amount of subluxing that the ulnar nerve is going to be able to do. Last but not least, we've got the posterior elbow here. Not as many structures or not as much pathology to see in the posterior elbow. Most of what we'll be looking at is the triceps tendon. The lateral and long triceps tendon heads coalesce into one, and that's the more superficial aspect. And you can see that correlates to number three here on the diagram. The medial head actually is a bit deeper and kind of comes in and attaches here. And that's number two on the diagram. And so occasionally you'll be able to distinguish the pathology. I haven't found too much clinical relevance from that, but it's still interesting to note in terms of when you're describing things. And then you can do your short axis view here. I typically like to go kind of back and forth along that fat pad just to make sure I'm not seeing any hypoechoic or anechoic fluid that would indicate a sales sign. This patient was referred for tennis elbow. They had this big kind of goomba that was really irritated and vascular on their lateral exam. And so I looked posteriorly, and this was actually an extension of... This was some tophi. So this patient had gout that had extended over to the lateral elbow. And so this is something you may see posteriorly, making sure that you're not... Don't go PRP that thing. That might make it more angry. So yeah, making sure you're scanning it. Look for the presence of vascularity and look on the posterior exam there. The elecronon bursitis... I don't have a picture of an elecronon bursitis, but if you do have a patient with elecronon bursitis, you know, making sure that you're using light transducer pressure so that you don't compress the fluid. And finally, real quick, the diagnostic exam. You can see this is just taken direct from my Epic templates. So typically I want to tell what part of the body ultrasound evaluation of the left medial elbow, for example. I like to tell what type of transducer I'm using and usually in the elbow it's a linear transducer. And then comparing it, as Dr. Bartolo said, comparing it to the radiographs and perhaps an MRI depending on if the patient has that. And then this is my template. These are obviously all normal descriptions and then I can kind of edit them when needed. The focus assessment, if you're just going to do a quick limited evaluation, is something I'll do if I just want to re-examine the lateral, you know, conic sensor tendon for whatever reason. But most of the time I'm doing a complete exam and this is my typical report. These are my references and thank you very much. And now I'm going to virtually introduce Dr. Lazaridis. Good morning everybody. My name is Marty Lazarus, and we will be talking about MRI of the elbow for the next 25 minutes or so. I'd like to start out by thanking Dr. Suhu for having me this morning, and I'd like to also apologize for not being present physically at the meeting, but we will see what we can do, and we have a lot to talk about, so why don't we get started. I'd like to talk about first the indications for why you would want to get an MRI of the elbow, and then briefly I'd like to talk about throwing mechanics, because I think it's critical in understanding the MRI images that you are going to be seeing, and I do believe that you should be reviewing all the MRI scans after the radiologist. We'll talk about anatomy, and we'll talk about pathology. Now the main indications, the reasons that you will be ordering MRI scans, there are really four separate categories that I like to talk about. The first and probably the most important one are medial side abnormalities, and what we're really talking about here is medial collateral ligament and medial epicondylar abnormality, common flexor tendon abnormalities, and ulnar neuropathy. If we go to the lateral side, the most common reason that you'll be ordering these exams is for common extensor slash lateral epicondylitis pathology, and then the third category is osteochondral abnormality or injury, and that's really DJD, loose bodies, OCD lesions, and occasionally occult fractures, and finally miscellaneous disorders, and actually miscellaneous disorders in this particular case are very important, because biceps injuries are going to be one of the top reasons that people will be ordering MRI of the elbow. So real briefly, let's talk about elbow mechanics and throwing mechanics, and the injuries occur most commonly during the acceleration of phase of throwing when the elbow is thrust ahead of the wrist into valgus extension, and you can divide the injuries into medial tension, lateral compression, and posterior or posterior impingement injury, and here's a schematic representation of what we're talking about here, and along the traction or distraction side of the elbow, and this is the medial side where most of the action is, we have injury to the soft tissues, whereas on the radial side or compressive side, we have osteochondral injury to the radiocapitular side of the joint space. So when we're talking about the medial aspect of the elbow where a lot of the injuries occur, we're really talking about ulnar collateral ligament injury, flexor pronator injury, and ulnar neuropathy, and we have occasional ulnar traction, osteophyte formation, and heterotopic ossification, which are more commonly chronic injuries within the soft tissues. So let's start with some anatomy of the medial or ulnar collateral ligament, and really it's the granddaddy of the ligaments in the elbow. It's the main stabilizer of the medial elbow during valgus stress, i.e. during throwing. It runs from the medial epicondyle to the coronoid process of the ulna, and more specifically, the sublime tubercle. It's thicker proximally and narrows down distally, and I kind of like to think about it as a reverse ACL, where the ACL is actually thicker distally and thinner proximally. It consists of three distinct bands or bundles, the anterior, the posterior, and the transverse. We see the anterior bundle here. The posterior bundle actually forms the floor of the cubital tunnel, and the transverse bundle is an ineffectual bundle that goes from the coronoid process to the olecranon process of the ulna. An injury occurs in throwing athletes, i.e. pitchers, quarterbacks, javelin throwers, anyone that's throwing. You can have a partial or you can have a complete tear, and we should be able to see these on the MRI scan. So let's start looking at some of these images. These images are called coronal images, and these are the images that you really want to focus on if you're looking at ligamentous structures in the elbow. It's as if you're looking at the elbow from straight on from in front with the hand in supination, and you can see here beautifully this dark thin rope of the ulnar collateral ligament, which runs from the medial epicondyle to the sublime tubercle. Notice the parallel margins in this particular ligament, whereas on the right, this is actually the more common appearance, which is a thickened proximal portion of the ligament with slightly increased signal intensity or slightly grayer or whiter than the distal part, which narrows down to a sharp point at the sublime tubercle. Now here's an MR arthrogram. We injected a cadaveric elbow with this contrast material, so all the white here is contrast material, and it beautifully outlines the undersurface of the ulnar collateral ligament, and we see that the undersurface can be very irregular at times, sometimes extremely irregular, but the most important thing that we want to see is that tight attachment at the sublime tubercle, so nothing gets by or below that sublime tubercle in this normal ulnar collateral ligament, and I also want to mention one structure that can be confusing when you look at an MRI scan within the capsule or joint margin, and that is the lateral synovial fringe, and we're seeing it out here. It's a small invagination of normal tissue, and having said that, it can become thickened irregular edematous and entrapped within the radial capitellar joint, and then it becomes symptomatic, but you have to know that it exists so you don't over-call these examinations, and here's a nice view of it. Again, coronal image, you see this invagination of synovium with a sharp point, which is normal, the lateral synovial fringe, and that's running just next to this structure here, which is the lateral ulnar collateral ligament, which runs from the lateral epicondyle, bypasses the radial head, and inserts on the ulna approximately and laterally. We also see the ulnar collateral ligament again, the common flexor tendon, nice thin dark structure, common flexor, excuse me, common extensor tendon here, nice thick dark structure, common flexor tendon here, and then another coronal image. Remember, the most important for looking at these ligaments, and we see the radial collateral ligament here, nice thin dark structure, just deep to that nice thin common extensor tendon, and we see the common flexor tendon on the ulnar side of the elbow here, and now an axial image. Axial image is like if you're cutting through a sausage in cross-section. This is what we're looking at. We're going to be going counterclockwise here, and we're going to start with this little round gray thing in here, which is actually the ulnar nerve, and that sits within a fat plane between the two heads of the flexor carpi ulnaris muscle. As we go counterclockwise, we see the pronator teres muscle. We see another small dark circle, which is actually the median nerve, which runs within a fat plane beneath the pronator teres and superficial to the brachialis muscle, and then as we go more counterclockwise, we see the radial nerve just deep to the brachioradialis muscle, and finally, we continue on to the anconeus muscle, if you will, posteriorly, and now we have an axial image on the left and a sagittal image on the right. The sagittal image, if you're looking at the elbow from the side, and if we're looking at coronal images for ligaments, we're looking at the sagittal image for biceps tendon, and this is the best image to look at it on the right here. So, we see the biceps in cross-section superficially, this round structure, dark black structure here, sitting on top of the brachialis muscle, and on the right, we see this nice long biceps tendon extending down from the myotendinous junction to its insertion on the radial tuberosity. Deep to that, we see the brachialis, and this is the intramuscular portion of the brachialis tendon, and you see the entire myotendinous junction running deep to the biceps towards its insertion on the proximal ulna, and here's one small anatomic point of the distal biceps tendon, and we can often see really nicely with an MRI scan, and this is separation of the two main heads of the biceps tendon. So, we see the shorthead on the left, and actually, the shorthead is kind of a misnomer, and it's kind of counterintuitive because it actually runs longer than the long head, inserts distal to the long head on a larger footprint on the radial tuberosity. On the right of the shorthead is the long head, and there you see it actually inserts more proximal on the radial tuberosity, and then the sagittal images. On the right, you see the superficial portion of the triceps tendon, and you see it inserts nicely and tightly on the olecranon process, and this superficial portion is made up of the lateral and long heads of the triceps, and that's superficial to the deep portion, which is made up of the medial head, and the entire myotendinous unit will insert on the olecranon process just deep to the superficial portion. The image on the left, again, is a sagittal image, and you see this curvilinear low signal, which represents the subchondral bone plate. Just superficial to that is this grayish-whitish area, which is actually the articular cartilage of the capitellum, and superficial to that, we see the anterior joint capsule, and if we extend that anterior joint capsule distally, we see it becomes the annular ligament, which wraps around and stabilizes the radial head. So let's start looking at pathology. This is a 21-year-old collegiate baseball pitcher who felt a pop, and we know now the normal anatomy, or the normal anatomic appearance, of the ulnar collateral ligament, and we see that there's a rupture of the distal aspect of the ulnar collateral ligament. There's a small amount of fluid that's extravasating through that rupture, and just as importantly, at least in my mind, is that there's a cyst in the distal capitellum on the radiocapitellar side. So this 21-year-old kid already has chronic valgus overload symptoms and cartilage degradation, i.e. early arthritis in the radiocapitellar side of his joint at the age of 21. Now here, I apologize for this image, it's not the best, but the story is compelling, so I always like to show this. This is a 20-year-old professional baseball pitcher who'd been having on-and-off pain, he said, since the age of 12. He felt a sudden pain while throwing a 99-mile-per-hour fastball, and we see there's a gap filled with fluid at the proximal aspect of the ulnar collateral ligament. So this is a complete rupture of the proximal portion of the anterior band of the ulnar collateral ligament, and the sad thing about this is this kid was over-pitched from grade school, high school, and college, and he said he felt since the age of 12 that his elbow would explode at any time, and it finally exploded, and it was actually not long after he pitched one of the greatest games, if not the greatest game in the history of Major League Baseball. Here's a 14-year-old football player who had his elbow hit by a helmet on the radial side exactly at the moment that his arm was fully extended on the ground in a foosh kind of position, and you see here all this white area within the bone marrow is edema representing radial neck and head fracture on the compressive side, or what has become the compressive side of the injury, and he has an avulsion of the medial epicondylar apophysis on the distraction side with a strain of the common flexor pronator group. So this is actually interesting because he has classic radial compression ulnar distraction injury without throwing, and this is probably the only case I've ever seen with it, but he was just unlucky enough to get his elbow struck on the radial side exactly while his arm was on the ground. Now let's go on to partial ulnar collateral ligament tears, and here you see a 17-year-old high school pitcher with medial elbow pain, and we see a nice normal appearing ulnar collateral ligament, thicker proximally, narrower distally, but the problem is there's some linear high signal white fluid just deep to the distal half of this tendon, and as we know now, this ligament should be attaching at the sublime tubercle, and it's not. It's distal to that, so this represents a partial undersurface tear of the ulnar collateral ligament. And this same kid had posterior pain also, and this is the same images I was using before for anatomy, but here we can look at pathology in this kid, and we see that his synovium, because his ulnar collateral ligament was not stable, he had a little bit of motion every time he threw the ball in his olecranon process until it started to pinch his posterior synovium, causing inflammation, thickening, and edema that we're seeing here. So this is evidence of posterior impingement in this picture. And another look at partial undersurface tears, we sometimes get people that ask for MR arthrography, and this is an MR arthogram, and you see that there is white signal fluid here. All this white is fluid that we injected, and it goes distal beyond the sublime tubercle, so this is another way to look at partial undersurface tears of the ulnar collateral ligament. And this actually is termed the arthrographic T sign, and you can kind of use your imagination to say that here's the cross of the T, and here's the other part of the T, and it's tipped over about 90 degrees, but the arthrographic T sign was originally described by James Andrews and his group at Alabama Birmingham. And if those symptoms persist and aren't taken care of, we can actually have a disruption of the entire ulnar side of the elbow and all the primary constraints. And that's what we see here. So on the right, you see there's a hole in the entire ulnar side filled with fluid or blood, and there's no ulnar collateral ligament. There's no common flexor tendon. And on the left, you see the tip of the torn, ruptured common flexor tendon. And if you look surgically, once you open up the skin, you look right through the hole in the common flexor tendon, you can grab the ulnar collateral ligament in the forceps, and we're looking directly into the joint space through that massive hole. Let's move on to osteochondral injury. Osteochondritis dissecans or OCD lesions are seen in young pitchers and gymnasts and unfortunately they carry a poor long-term prognosis particularly in gymnasts, particularly in female gymnasts. Panner's disease, which we don't have time to go into today, is a self-limited entity which has very similar imaging findings but usually seen in the younger population than OCD or true OCD lesions. And then we'll look at osteoarthritis as well as some other arthritis as well as loose bodies that these patients can get. So here's the classic appearance of an OCD lesion of the capitellum. We see this biconvex focus of gray area in the distal capitellum and it's replacing a portion of the marrow fat that we see normally in this part of the capitellum. On the right you see this white line which represents a small amount of fluid at the base of this lesion. So this indicates that this is an unstable OCD lesion of the capitellum. And here's another case. These are sagittal images. Again we're looking from the side a large amount of fluid. This white stuff is all fluid and we see this OCD lesion and this is actually a hinged OCD lesion. You see it opens up posteriorly where the arrow is and anteriorly it's attached. So you can just fillet this thing open hinged anteriorly and on the right a couple images over towards the radial side. Again you see the white line at the base of this lesion indicating that this is an unstable OCD lesion. And if these aren't taken care of then we can end up with loose bodies within the joint space. These are two sagittal images. You're looking at it from the side and you see here a round loose body within the olecranon fossa of the elbow and on the left you see a wafer-like disc-shaped loose body within the olecranon fossa and this will mechanically obstruct full extension in the elbow. And as you go from high school to college to professional many many many of these pictures have extension lag because of these loose bodies. And we wanted to find out in this case exactly how many were we dealing with in this young picture. And so we did a CT arthrogram and you see multiple small rounded gray loose bodies floating around the joint. So this kid had a ton of loose bodies related to his pitching. Here's a different kind of arthritis. Here's rheumatoid arthritis. This is a 41 year old male with elbow pain and swelling and there was a joint diffusion on the plain films but we still didn't know what was going on with this guy. So we got an MRI and the MRI shows you that there's joint fluid but there's also this grayish area throughout the synovium and this is massive synovial thickening and irregularity and synovitis throughout his joint. In addition he has very early erosive change at the posterior aspect of the capitellum on the right and the posterior aspect of the base of the olecranon process on the left with surrounding prominent bone marrow edema throughout. And so this is a 41 year old with rheumatoid arthritis joint diffusion and severe synovitis. Now let's go on to an important important entity and that's biceps tendon injury. Clinically this results from acute eccentric overload, tears distally at the radial tuberosity insertion and clinically you'll feel a palpable defect and bulge due to the retracted muscle belly. But before we get the full rupture oftentimes you'll get biceps tendinopathy and radial bicipital bicipital or bicipital radial bursitis and that's what we're dealing with right here. So you see fluid within the radial bicipital bursa but you also see thickening of the biceps tendon with edema throughout and it's still attaching normally. There's no tear, there's no retraction and certainly if this continues on we'll get what we see here which is complete rupture of the distal biceps tendon. You see the nice tendon margin, you see all the white area around it representing edema and or hematoma and in this particular case it's not retracted significantly more than about one and a half centimeters or so. Another thing I want you to take note of on the left as we said previously this is a sagittal image and for biceps injuries and triceps injuries sagittal images are where the money is and you should be looking at those images specifically. Here's another case these are a coronal image and a sagittal image and you see this accordion black snake-like structure representing a retracted biceps tendon distally. You see the surrounding edema and hematoma around it. Another case we see even better this snake-like retracted biceps tendon and then the best way to look on the left sagittal image of the biceps tendon you see the entire torn retracted tendon but the important thing about looking at the sagittal images is you can actually measure the amount of retraction of this tendon on the same image that you're looking at the biceps itself so this is really helpful and gives you a ton of information. And this is the last bit of anatomy I just want to point out before we go on and you see this curvilinear dark little rope-like structure that attaches at the distal biceps and fans out to extend over the flexor pronator group and this is called the lacerdis fibrosis and this is critical in these cases because it holds down the biceps tendon distally. Without this when you rupture the biceps tendon you can have tremendous superior retraction of the tendon margins into the arm and here we see complete distal biceps tendon rupture. There's a hole where the biceps should be filled with fluid but we also notice that there's no lacerdis fibrosis on either of these axial images. T2 weighted image on the left, T1 weighted image on the right. And we pointed out anatomically the separation that you can sometimes see with MRI between the short and long head of the biceps tendon. Well here's a case of a 44 year old male who moved a computer, felt a pop, and if we look on the sagittal, excuse me, the coronal image on the right you see a nice thin taut dark long head of the biceps but we really don't see the short head but we really don't see the short head and this is where it's supposed to be inserting on the radial tuberosity just distal to the long head. And on the axial images you see that a nice insertion of the long head of the biceps on the radial tuberosity on the left but on the right there is no insertion of the short head. So this is a tear, partial tear really, of the short head of the biceps with preservation of the long head. Let's go on to triceps tendon injuries now. We know some of the anatomy. Let's look at some pathology. Here we see the tip of the superficial portion of the triceps tendon which is made up of the lateral and long head and it's completely ruptured and it's retracted about four to five centimeters but we still see that the medial head or deep portion is attached normally at the olecranon process. So this is a partial thickness tear of the superficial aspect of the triceps tendon. Here's a 25-year-old National Football League offensive lineman with sudden posterior elbow pain while he was blocking a D lineman and you see here there's a rupture of the distal aspect of the superficial portion of the triceps and on the right you see the deep portion of the medial head, nice, dark, taut and attaching normally at the olecranon process. So this is a partial thickness tear involving only the superficial portion. Here's a 31-year-old NFL cornerback and he had a previous rupture of his triceps tendon with repair and he had a new injury and the image on the right actually these kind of dark things hard to see but these dark areas are actually the suture anchors that were put in for the initial repair of his ruptured triceps and on the new study you see that at the ulnar aspect he has a nice post-operative appearance that's attaching normally to his olecranon process but if we go a little bit to the radial side you see that we have a full thickness partial width tear of that radial portion completely macerated retracted with surrounding edema and or hematoma. So this is a full thickness partial width re-tear after triceps repair. Now let's go to the lateral side and what we're really going to be talking about with the lateral side is the common extensor tendon because that's the one that you'll probably be seeing most frequently clinically and ordering most MRI scans for. We'll touch on the radial collateral ligament as well as a lateral collateral ligament. So here's a coronal image and now we know normal anatomy of the common extensor tendon and we see here how thickened the coronal ligament is. And we see here how thickened the proximal aspect of the common extensor tendon is here with abnormal increased signal intensity. This is the classic appearance of common extensor tendinopathy or tendinosis. Note that there's no fluid in here there's no partial thickness tear at this point and if this isn't treated and goes on then we'll get to fluid forming within the tendon in a partial tear of the common extensor tendon. And if this patient continues to play tennis and still has issues this can eventually lead to complete lateral complex injury and that's what we're looking at here. These are coronal images and you see the high signal fluid through a hole of the lateral complex. So the radial collateral ligament should be deepest here then we should see the common extensor tendon as well as the lateral ulnar collateral ligament and all three of those structures are gone in this particular case. Now this really doesn't fit into any category but I love this case so much that I always talk about it. This is a 22 year old pitcher who while tagging out a runner at the plate after a wild pitch slammed his elbow into the teeth of the runner subsequently developed pain swelling and a fever. And you see here that there's fluid in the olecranon bursa and there's also abnormal increased signal intensity in the triceps tendon with a full thickness rupture of the triceps and there's cortical destruction of the olecranon process with bone marrow edema throughout the olecranon process. So this poor guy had infected olecranon bursitis insertional triceps tendinopathy with full thickness infected tear and osteomyelitis of olecranon process all because he couldn't throw a strike so it's a pretty sad story. And of course we briefly discussed occult fractures. Oftentimes if the x-rays are negative we'll get an MRI scan and here we see the kind of classic appearance or pathognomonic appearance really of fluid within the joint space. In fact there's a fluid fluid level indicative of a lipohemarthrosis on the left and on the right you see this impacted radial head fracture that we and on the right you see this impacted radial head fracture that we were unable to see on plain films. Let's finally go on to ulnar neuropathy. The ulnar nerve is the most frequently injured nerve within the elbow. It lies superficial in the cubital tunnel and the most common cause of ulnar neuropathy is cubital tunnel syndrome. So what are the causes of cubital tunnel syndrome? Well we can have over chronic overuse from multiple causes. You can have an acute external compression from a single traumatic event. We can have chronic external compression as in on the operating room table. You can have physiologic compression i.e during sleep. If you go from an extended elbow to 90 degrees of flexion you can open up the medial elbow as much as 10 millimeters stretching the ulnar nerve stretching the arcuate ligament over the ulnar nerve and decreasing the space within the cubital tunnel up to two to three millimeters. You can have space occupying lesions i.e a a cyst. You can have post-operative causes of a cubital tunnel syndrome and ulnar neuropathy either within the cubital tunnel or extrinsic to the cubital tunnel such as in an ulnar nerve transposition that you might see with Tommy John surgery. So what are we going to see on an MRI scan that you can be looking for? We'll see increased signal on T2, a somewhat whitish appearance, increased cross-sectional area, visualization of the individual fascicles and you can see perineural edema as well. And so here's an axial image on the left and the coronal image on the right. You see fluid representing a ganglion cyst within the cubital tunnel but looking at the ulnar nerve itself you see it's markedly enlarged and if you look closer you can see the lines of the individual fascicles on both the axial and the coronal images representing neuritis. Here's a 24-year-old NFL defensive tackle, staspost elbow dislocation and again you see thickening in the ulnar nerve within the cubital tunnel on both the T1 and T2 weighted axial images and you also see especially on the image on the right the individual fascicles within the nerve. And if we look further, coronal image, the entire extent of that nerve within the cubital tunnel is thickened and edematous and on the right you see again the thickened nerve but just deep to the nerve you see the posterior band of the ulnar collateral ligament which actually forms the floor of the cubital tunnel. It's thickened, edematous and partially torn so we have a high grade sprain of the floor of the cubital tunnel in addition to ulnar neuritis related to the elbow dislocation and that traumatic event. So MRI is a sensitive way to assess the soft tissues and osteochondral structures of the elbow. Knowledge of throwing I think is critical when you are interpreting these images and coronal sequences are best to evaluate the ligamentous restraints and saggial and or axial images are best for looking at tendinous structures. So thank you very much for having me. All right so hopefully that wasn't too bad as a last minute switch up as he couldn't join us today. I think we have like one minute before our session officially ends if anyone has any specific questions for our panel or else feel free also to come up afterwards if you want to ask any of our esteemed panel questions. I'm guessing with everyone walking out of the room that no one has any questions so we will end for today but feel free to come up if you have any specific questions. Thank you.

elbow x-rays

different views

anatomical landmarks

elbow ultrasound

pathology examples

ultrasound as complementary tool

dynamic imaging

ligament tears

osteochondral injuries

nerve entrapment

MRI images