 Hello and welcome to noon conference hosted by MRI online noon conference connects the global radiology community through free live educational webinars that are accessible for all and is an opportunity to learn alongside top radiologists from around the world. We encourage you to ask questions and share ideas to help the community learn and grow. You can access the recording of today's conference and previous noon conferences by creating a free MRI online account. Today we are honored to welcome Dr. Stephen Pomeranz for a lecture entitled MRI of the elbow. Dr. Stephen J. Pomeranz is the CEO and medical director of pro scan imaging chair of Naples Florida Community Hospital Network and the founder of MRI online. He's authored numerous medical textbooks in MRI, including the MRI total body atlas. Dr. Pomeranz is also an avid conference lecturer and chairs the fellowship training program in MR and advanced and imaging. At the end of the lecture, please join Dr. Pomeranz in a Q&A session where he will address questions you may have on today's topic. Please remember to use the Q&A feature to submit your questions so we can get to as many as we can before our time is up. With that we are ready to begin today's lecture. Dr. Pomeranz, please take it from here. Thank you, Jackie. Let me see if I can share my screen appropriately. I think I've got it. Does that look right? Looks great from here. Great. Thank you everybody and welcome to MRI online now known as Medallity. We're talking MRI of the elbow and we're going to focus initially on anatomy and then get into some additional details which will break down for you in a moment. You know, the octopus is flexible with an infinite number of movements. It's configured with three joints, including an elbow to perform essential functions. So that's three joints per tentacle. So that's eight tentacles times three joints. There are 24 joints in the arms of an octopus. So in anatomy, we're going to focus on some key checkpoints, specifically the skeleton. We're going to look at some signs of dislocation like the Osborne Cotter lesion. We'll look at some basic anatomy, ruse, bumps. And then we'll talk about ligaments, the medial and lateral collateral ligament complexes, the fat pads, the tendons. And we'll show you where some of the major nerves live in order to diagnose and trap neuropathies. The cubital tunnel, pronator teres tunnel for the median nerve, the posterior interosseous nerve or radial tunnel and the anterior interosseous nerve. I'd like to start out a little bit with technique. The patient can lie with the arm at the side in a much more comfortable position using either a rigid or flexible coil. I like to have my patients with their hand in a thumb up position, which is most comfortable for them. So somewhere between pronation and supination. Some patients when you have to have very high resolution imaging with microscopy coil scanning may have to go into the Superman position arm over the head. But this is only sustainable for about 30 minutes. There are some unique issues with the elbow that are often present that require some prompt intervention. First of all, the fractures may be quite complex. They may involve the interosseous membrane and the nature of the fracture may indicate the nature of the injury and the presence of elbow dislocation. We've got the Essex lopesti fracture, the Montague fracture, coronoid fractures with the odriscal classification, fractures of the distal humerus and radius. And some of these, like these first two are often bored questions. Now let's begin with some gross anatomy. The elbow is composed of three bumps and two grooves. One of the bumps, the capitellum, and it fits very nicely into the concavity of the radius. So the radius should be pretty balanced at the apex of this concavity. For when it starts to shift out laterally, you may have postrolateral instability syndrome. You've got an ulno-humeral articulation right here. You've also got a radial ulnar articulation right here. Another variation that you're going to see in the elbow is something called the lateral synovial fringe. And the fringe is this sort of ill-defined tissue right here. And sometimes with that fringe is a more condensed band. You know, it's like a plica that you might see in the knee. Some people have even called it a lateral plica. Then posteriorly you often have these very small vertically or obliquely oriented vascular grooves that are hyperintense, not to be confused with capitellurostocondylvifex. Now many injuries that occur in the elbow occur with a fall on an outstretched hand, also known as a bush mechanism of falling. You get axial compression and bending of the elbow. And sometimes when you try and get up, your arm is on the turf or on the ground and somebody hits you from the back of the elbow, pushing the elbow forward. And this may give you a varus deformity. On the other hand, if you have a hyperextension injury, you will have a valgus deformity. You can also have supination type injuries, etc. So the mechanism of injury is easily ascertained by looking at the pattern of bone anatomy and this is going to become more clear in a few moments. So on the left is a diagram showing you grossly the skeleton with the ulna, the coronoid process. Here is the humerus and here are the teardrops on either side of the humerus. And most of you are familiar with the teardrop sign, especially when the fat pad anteriorly is displaced forward on an x-ray. You know that you have an effusion. Here is why that occurs. Here is the fat pad with some of the fibers of the brachialis distended superiorly and anteriorly by a large effusion. You can see a microchobacular injury of the radius and for those of you paying close attention, you can see the osborn cotteral fracture of a dislocation that has occurred in the elbow. More on that in a few moments. So here is an example of an eight-year-old with a joint effusion. This time the joint effusion is small enough so that you see the posterior fat pad, but not the anterior fat pad. Here is another patient with a larger joint effusion. Now you see both the posterior fat pad and the anterior fat pad that is lifted up and of course buried in there somewhere is the attachment of the brachialis. Now we said the relationship of the humerus, ulna, and radius is divided up into two grooves and three bumps. And here are those bumps. Here is the capitular bump. Here is the medial and the lateral humeral bump. This is known as the capitular groove. This is known as the trochlear groove. And there should be a best fit scenario where this part of the jigsaw puzzle fits into that part of the jigsaw puzzle and the same thing is true on the radial side of the articulation. When that best fit configuration is lost, then we refer to this as the sloppy hinge syndrome. Now if you drop your arm to your side, all of you will notice that your arm doesn't go straight down. Your arm comes down and goes off in a slight valgus orientation. So this is known as the valgus carrying angle. It's about six degrees. A couple of other interesting unique features to the elbow. The anterolateral radius is not covered by cartilage, so don't confuse this with an OCD. The anterior capsule is loose inflection and tight in extension. And the elbow, along with the humerus, this is vital information, have the tightest capsules for the size of the joint, which means that when you have something in these joints, like PVNS, you're going to get the largest pressure types of erosions. The synovium lies the inner aspect of the fibrous membrane and redundant synovial folds are very common, especially posteriorly in the electronon fosin. You've got synovial membranes, the paraelectronon in the back, the perihumeral in the front, and the periligamentus medial and lateral, and we've already shown you the synovial fringe. And here it is again. Here is the lateral synovial fringe. It can get pretty big, pretty deep, and pretty conspicuous. It can even masquerade as something akin to a plica. When they get symptomatic, they're usually thickened about three millimeters or greater, but the key is to see inflammation in this area, and that inflammation may extend into the cartilage of bone or bone. So while these reflections are normal, they can be symptomatic just as they can be symptomatic in the knee. Here's an example of a symptomatic one. Here's a diagram, short and stubby. There are some abnormalities in the diagram in the capitellum, in the radius, even though there is some bare area over here. And then if we go down here inferiorly to the MRI, look at how thick these tissues are with an effusion as a secondary sign. This is all part of the fringe right here. This is a bit too thick. And then when you look at the gross specimen arthroscopically, you can see quite a thick synovial fringe projecting inward. Let's take a 21-year-old with elbow injury after being positioned in a sling for quite some period of time. The trauma was relatively minor. Now, when the patient came out of their sling, which was put on the patient for medial symptoms, they ended up having more central ill-defined symptoms. And because of the restriction of this sling and the alteration in pronation and supination, this patient developed from the sling, from the restriction an erosion that occurs right at the radio trochlear bump right here, the central bump. And so here's an erosion that occurred as a result of elbow restriction. You can also see that the elbow is normally dry and there's a small amount of what I call trace effusion of the elbow. So in a young individual, the elbow should be dry. Here is the sagittal or lateral projection demonstrating what is a pretty substantive erosion in the back of the humerus in this patient. There's also a little bit of thickening of the posterior perelectronomplica, but do not confuse this object right here, this defect, which is a normal defect that occurs in the trochlea in the sagittal projection. We also said earlier that there are normal areas of irregularity and vascular grooves in the back of the capitulum. So those are two important variations. Back of the capitulum irregularity and right in the trochlea groove seen in the sagittal projection almost exclusively. Here's an example of somebody with an abnormal elbow, so-called sloppy hinge syndrome. Look on the right at the T1 weighted image. You could be on your fourth pint of Jack Daniels and you can easily see these osteophytes projecting on either side, but look at how the ulna does not sit directly into this groove right here. That apex is off from that depression very slightly. So everything is starting to shift. So despite the fact that there is OA, there is already the development of sloppy hinge syndrome so that when the patient flexes and extends, their range of motion is diminished. The friction between the structures is enhanced and eventually they knock off a piece of cartilage anteriorly, which is where cartilage likes to go here and here near the electronome. Here's another example of somebody with a sloppy hinge not shown, but that friction has also irritated the posterior perelectronome plica. Remember we have several plica, one in the front, one in the back, one medial, one lateral. The most famous one is the lateral synovial fringe. The second most famous one is the electronome fringe. Or plica, and here it has induced synovial hypertrophy. No, this is not fluid. It's too spectrally looking to be simple fluid. It's inflamed fluid with synovial hypertrophy. Bursa. Primary bursa are often flat. They're subcutaneous. They usually are over bony protuberances and they are synovial line. They may be tethered to the skin of the periosteum. Example, the electronome bursa, the annular or sacroform recess bursa. Locations for bursa, subcutaneous, submoscular, peritendinous, periligamentous, and subfacial. You can have secondary bursa that form. So-called pseudobursa, like adventitial bursa that form in the first and fifth metatarsal head callus. Causes of bursa, bursitis include acute or repetitive trauma, gout infection, tumor-like processes, and inflammation. If you see electronome bursitis in a 40 to 50-year-old man without a history of trauma, it is gout till proven otherwise. The differential diagnosis of bursal distension includes hematoma and degloving, fascial-de-gloving, so-called Morel-Lavallee syndrome. There are a few eponyms in bursitis, including electronome bursitis, which is sometimes called minor's elbow, and sometimes it's also called student's elbow because the student leans on their elbow while studying for the amcater, for the big pathology exam. There's an example of electronome bursitis, but no, not just any bursitis. Look inside it. It's got this funny-looking heterogeneous tissue. It's in a man. The man is in his early 40s and has stated, this is gout till proven otherwise, and it was gout. On the other hand, this is a woman in her 40s. There is distension everywhere, in the back, in the front, but there's also these large confluent areas of intermediate siglintensity. Well, I suppose they could be TOFI, but with a capsule markedly distended, it is a woman. And the extent of synovitis, you have to choose rheumatoid arthritis as the first choice, and it is. There is a focal area of panis formation in this patient with RA. Now let's turn our attention to elbow instability. We've got static and dynamic stabilizers of the elbow. The main static stabilizers are the lateral and medial collateral ligaments. The lateral collateral ligament can be broken down into a proper anterior short-study collateral and a slightly more circuitous, thinner lateral ulnar collateral ligament. The medial collateral ligament can be broken down into three segments, but the most important one by far is the anterior bundle of the MCL. The dynamic stabilizers include the common extensor on the lateral side and the common flexor on the medial side. Common extensor, lateral, common flexor, medial, and it makes this triangle almost like a fortress, and this is further supported by the conformity and the fit of the trochlea, sorry, the trochlea, the humerus, and the radius. So now let's begin with the lateral side of the elbow. Let's begin with the medial side of the elbow. My apologies. The anterior bundle of the UCL is the most important stabilizer, the floor of the cubital tunnel formed by the posterior bundle, the roof of the cubital tunnel formed by the transverse bundle, and these hardly ever tear unless you have a massive dislocation. The transverse superficial bundle in the back is sometimes referred to as the ligament of Cooper. Now the reason these are important is because they house the ulnar nerve. The anterior bundle of the UCL is fan shaped. It spreads out a little bit distally. It also spreads out proximally, and this spreading phenomenon may reduce the signal intensity as you go more distal or go more proximal from that more tight dark signal intensity that you see in the mid-substance. Now like the knee, like the knee, the UCL, the anterior bundle of the UCL is a three layered dragon. It has a superficial layer which is very subtle. It's very hard to see. It's the flexor digitorum superficialis aponeurosis, which I can only show you here as this little whitish area because it's inflamed. This is what a grade one UCL sprain looks like. Then the next layer which is analogous to the tibial collateral ligament is the anterior bundle of the UCL. Then the next layer which is analogous to the menisco femoral and menisco tibial ligament is the capsular layer. So layer number one, layer number two, layer number three. I'm not going to go through the gross anatomy on this specimen due to time constraints. Let's take this world famous, nationally famous quarterback who had a deceleration injury while trying to throw the ball. He went back into the game. His deceleration injury occurred when the hand struck another player's helmet. He could throw, but he could only throw 30 to 40 yards. Normally he could throw 60 yards with only 60% velocity. He came out of the game and we performed this mighty mouse superman position, prone position, arm over the head, high resolution microscopy image using a specialized coil, and on the T1 weighted image it doesn't look too bad. However, look at this little space here. I really like this to snuggle up all the way onto the sublime tubercle of the omen. I don't like to see any space here at all. I can't allow half a millimeter or a millimeter as long as there's no inflammation. Now let's go to the proton density fat suppression image. We've got three findings here. I've got two of them labeled one and two. Labeled one, swelling of the flexor digitorum superficialis aponeurosis. And that arrow below it looks like it's pointing to the same thing, but it's really not. It's pointing to this little divot right here. And then wanted to get too close, a partial tear of the mid substance on the outside surface, but also on the inside surface. We're talking microns of resolution. And finally, the last finding, which I have labeled number two, is this separation, this stripping of the distal bundle of the UCL from the sublime tubercle of the omen. In a consultation in New York City, the aggressive physician said this must be repaired. However, we said that based on our 20 or more years of experience that this would heal, he decided to get a second opinion from Peyton Manning's doctor over in Indianapolis who also said it would heal and the injury occurred in November by May. He was throwing full force without an operation. Had he had an operation, he would have been out for over a year. So the microscopy coil and its high resolution and the experience really saved the day on that one. Here's a coronal projection showing you one that's much easier. Band shaped proximal UCL anterior bundle. The distal bundle is separated. You can see the space from the sublime tubercle of the omen, a fairly easy one. Elbow dislocations. Here you see anterior dislocation of the humerus relative to the ulna and the radius. Best appreciated on the true lateral projection, although I have multiple obliquities here for you. You already saw this example showing you the teardrop sign with diffuse swelling and blood in the joint fracture of the radius, the Osborne caudal dislocation fracture, analogous to the heel sax injury in the shoulder. Let's take a look at something that could easily be misconstrued for this, a look-alike. This is not an Osborne caudal lesion because those are acute. Those occur with dislocations. This patient has never had a dislocation. So knowledge of the history is your friend, especially an orthopedic MRI. Sclerosis is also helpful, right? We got sclerosis dark on MR, dark on CT. The abnormality is markedly etched. You can see an erosion higher up off to the side. So no, this is not an Osborne caudal fracture lesion. It's a chronic posterior and trochlear osteocondrial erosion secondary to abnormal friction and valgus extension overload in somebody with a sloppy HIN syndrome. Here's a trochlear abnormality in another individual that also has sloppy HIN syndrome, another thrower. This one is also etched and chronic, and the patient also has never dislocated. Look how sharp-edged it is. Let's talk about the stages of posterior dislocation. I don't want you to memorize these zero through three. Some people go one through four. I'd like you to just think about it with a little bit of common sense. They've subluxed or dislocated. All the collaterals are intact. They've subluxed or dislocated. The next thing you do is you check the lateral side, both ligaments. You check the medial side, all three components of the ligament. And then finally, the last thing you do is you check the skeleton. If you just do that and describe, you don't need to go to these stages unless you're an MSK radiologist performing at a high level. And even then, the surgeon doesn't really care about your grade just so that you get the anatomic information right. And this is a diagram just showing you these grades zero through three. Not so important. Let's take this 23-year-old man with laxity of the medial collateral ligament and a type I coronoid fracture. And yes, there are. There are types of coronoid fractures that you can think about a little bit like dense fractures. You know, you got the dense tip. You got the dense body. You got the dense base. Coronoid fractures are a lot like that. Sometimes you may see the coronoid break off and you may get loose bodies floating around within the joint that have come from the coronoid. Here's a sagittal T1. Here's a sagittal PD. Here are some fibers, some superficial fibers and some fibers of the brachialis, the deep fibers of the brachialis attached to the coronoid. So that's a problem. There's the capsule right here attaching to the coronoid. That's also a problem. But where is our coronoid? It has taken a vacation. So the tip of the coronoid has come undone. Now these areas that are located in the joint which is distended with fluid represent coagulated blood. The fragment of the coronoid is right here. So-called loose bodies. Here's another dislocation. If you went back and looked at the grading system usually the dislocators with UCLs are kind of a higher grade. But sometimes you get them both. Sometimes you get both the lateral side and the medial side. Here's an easy one. All I want you to do is figure out where the collaterals are. I'm not going to show you the lateral side just yet but the medial side, fan shaped, that's okay. A little gray, that's okay. It comes down and it does not snuggle right up onto the sublime tubercle of the illness. So this is a distal UCL tear in a patient with a known clinical dislocation. Now here's the same patient. We're not done yet. We said the UCL was torn. But we said you can get them both and this patient had them both. Here's the proper collateral ligament. It might be a little space there but here clearly there is not abutment attachment. There is delamination of the proper radial collateral ligament from the radius. So he's got it on the medial side. He's got it on the lateral side. Now a kiss in cousin of the proper radial collateral ligament is the lateral ulnar collateral ligament also known as the luckle. It comes off from the back and wraps around the radius to insert on the supinator crest right here. The supinator crest of the ulnar. This shows it coming out and around under the ulnar but not so well. You can't really appreciate how it ducks underneath the radius. Sorry, how it ducks underneath the radius and inserts on the supinator crest. So here's the takeoff of the luckle coming around behind the radius and here's a double takeoff right here which isn't too common. Here's again a view of the luckle it has a circuitous course rather than a straight thick stubby course that we see with the proper collateral ligament. Another stabilizer is the annular ligament and there's a small recess in here known as the saciform recess. Let's look this time at the sagittal projection. Do not confuse the common extensor mechanism which is a little more superficial from the lateral ulnar collateral ligament which sometimes has a funnel shaped takeoff right here usually single bundled around the back of the radius to insert on the supinator crest not shown but this area of distention in the proximal radial neck is known as the saciform recess. Here's an example of both the proper short stubby anterior proper collateral ligament with nice snugly attachment to the radius and here's the takeoff the funnel shaped takeoff of the lateral ulnar collateral ligament we don't see the rest of it because it's just simply going out of plane from this one slice but it'll make its way over to this crest which is known as the supinator crest. Nurse maid's elbow we all learned about that in medical school if you're a little older like I am we used to say well what is that well they said well it's a pulled elbow well what is that well we're not sure what the anatomic abnormality is but maybe it's an injury to the annular ligament and maybe the radial head slips out of there we now know that to be true so our positing about what it was was correct wasn't my positing people much smarter than me posited it at children's hospital and here we have the swollen bloody interrupted annular ligament you can't appreciate that the radius is subluxed but it is so another type of lateral collateral ligament insult is a 50 year old female who complained of persistent lateral right elbow pain with crepitus and right hand numbness since a motor vehicle accident that occurred in July this one's quite easy look at our gorgeous ulnar collateral ligament anterior bundle band-shaped and comes down and attaches snugly and neatly on the sublime tubercle of the ulnar but not not the radial collateral ligament that is stubby and never reaches its position onto the distal humerus superficial to it is the common extensor mechanism let's take this 39 year old man with posterior chronic pain rule out ligamentous injury with elbow dislocation here is a sagittal view showing a much bigger coronoid fracture there it is there's the big chipper right there and every time I think of chipper I think of the movie Fargo that's maybe not such a healthy thing but there inside the joint is an effusion and there inside the effusion that is blood that is actually not a fragment it's not dark enough to be such if you see this now you've got to search for the position of the capsule which looks pretty good attaching to the tip you might search for the attachments of the brachialis which looked pretty good that wasn't the point of the study now there is an adriscal classification of coronoid fractures and generally the higher the grade the more violent the dislocation it's pretty easy because the tip is grade one if you get deeper down more posterior on the coronoid the fractures get bigger the fragments get bigger and the dislocations get worse so it's not so fancy the adriscal classification of coronoid fractures but here is really a key fracture along with the coronoid fracture that helps you decide you've had a dislocated elbow and that is the osborn caudero lesion which is the trigger of the hilsax lesion in the shoulder it's on the posterior aspect of the humerus and an anterior dislocation and it's often a sign of a medial or collateral injury as well now don't confuse this sort of undulation in the back right here which is more superficial not associated with edema and unfortunately I'm not showing you the edema with this much deeper more etched defect there are two edges to it this is a real osborn caudero the regularity and the one on the left is not here is an example of a patient that has sustained a varus insul there is your collateral collateral ligament it really never makes it to the humerus and here it's clear here's the T1 weighted image this is the lateral owner collateral ligament it looks like this it should look like this kind of funnel shaped and then continuing on and then right around the radius on its way to the supinator crest it is clearly not doing that so that is a local tear now compare that, you're in the back now these are both pictures of the local it's a little clearer on the T1 that it is on the stirrer but then have a look at a more anterior slice the more anterior slice shows you the fat stubby cigar in its mouth of the radial collateral ligament the proper collateral ligament going from the humerus to the radius so that one's intact so this was a pure local injury here's a patient with postural lateral recurrent instability syndrome frequently in that phenomenon both the common extensor mechanism which it is the under surface of it is injured the common extensor may be swollen it is, it is here again but where is your proper collateral ligament you don't really, the space is completely empty and as you go back a little bit, I mean where is your local the local is peeled off right here you have this smoky high signal intensity tissue on the T1 you see virtually nothing because it's filled in with granulation tissue and inflammatory tissue so that one had both a proper and a posterior lateral ulnar collateral ligament injury or luckle both components of the LCL 46 year old female fell on 5.1.21 she had a dislocation and this one was flat out nasty this is a low field 0.3 Tesla machine T1 coronal PD, sorry stir sequence at low field and this is your water and fat weighted image where is your lateral collateral ligament you're pretty far anterior so that's the proper it's just truncated and cut off but where is your ulnar collateral ligament anterior band it's reduced to a pile of dust that's what's left of it right there never makes it to sublime tubercle so both of them are torn it's a complex instability and with cases like this now you really have to worry about the rest of the medial collateral ligament you know the posterior bundle and the transverse bundle I mean look at that thing right there the posterior bundle goes on the road to perdition it goes nowhere it's truncated right there the transverse bundle superficially goes nowhere it's just floating out there in the breeze the anterior muscle groups are interrupted and the the ulnar nerve is right here fortunately the ulnar nerve isn't really much involved it is a little bit of damage but this patient has all three components of the medial collateral ligament that are trashed let's turn our attention now to tendons and muscles we've got anterior posterior medial and lateral on the tendon side on the muscle side we've got biceps brachialis trisepsiconeus flexors and extensors let's talk a little bit about tendons now tendons are usually oriented in the long axis there are tendon subunits known as fascicles or bundles and within these bundles are microfiber units so there's units upon units upon units you can get infiltration of tendons without interruption of these subunits aka gout you have endotendon the surface of the tendon is connected to epitinon epitinon but that does not equal a sheath you can also have epitinon the common extensor and flexor tendons have epitinon you have the anterior and posterior biceps the brachialis and the triseps they all have epitinon then you have peritinon this is loose aryler connective tissue that's applied to the epitinon it's the outer most layer the epitinon is seen most classically in the achilles and the patellar tendon in the achilles you absolutely get peritinonitis and then you have true tendon sheaths which replace the peritinon and most of these not all but most are synovial lined they're less fibrotic than their peritinon counterparts the nomenclature is based on depth orientation the sheath and also when you're describing tendon injuries delaminations versus splits that's probably a story for a little bit later or another day you can have tendon infiltration you can have tendon retraction and the descriptors can get very complex and I get complex when we're talking about the shoulder but I don't have time to delve into all the nomenclatures for tendon injuries in the elbow but let's start out with a little bit of simplicity here there's the anterior bundle of the UCL it's not perfect it's got a little bit of signal between it and the sublime tubercle fortunately this is not a thrower it looks a little better on the T1 weighted image and the overwhelming majority like all of it is related to this large hypertrophic tear involving the flexor pronator mass which is how we would describe it on the MRI with globularity we'd give it a length a width and a depth and see if there's full delamination with retraction which in this case there is not let's look at this 43 year old referred for severe sharp and dull pain on the inner elbow since a work related injury this is a little more typical of what we have come to know and love as medial also known as golfer's elbow on the other side you've got tennis elbow and you usually see these focal five to eight or nine millimeter areas of deep under surface tearing that have a strong predilection for the extensor carpe radialis brevis or E, C, R, B we've also got a beautiful view of our local our funnel shaped local origin coming around going to the crystal supernatoris of the ulna that's beautiful and there's the common extensor mechanism that is also beautiful and there's our anterior bundle of UCL also beautiful with medial epicondylitis syndrome the pronator teres its origin is above the medial epicondyle humoral head and it has an ulnar head that attaches to the coronoid process so the coronoid process is a busy beaver you've got portions of the pronator you've got portions of the brachialis going there and you've got the capsule going there so evulsing it is not a good thing then you've got insertion on the tendinous lateral aspect of the radial shaft of the pronator teres so the pronator teres has an origin of the medial epicondyle but the coronoid as well the median nerve is separated from the ulnar artery by the ulnar head of the pronator teres and it lies between the two heads and can get compressed between those two heads and this is known as pronator teres syndrome or honeymoon paralysis 14 year old man with injury from pitching a baseball about a week ago here is the frontal coronal projection we've got swelling of the apophysis swelling of the underlying bone because the apophysis is doing a little bit of wiggling, some interstitial tearing of the adjacent musculature and generalized swelling and this is what advanced apophysitis looks like in the immature elbow but do appreciate the integrity, the intact appearance of the anterior bundle of the UCL even though it's swollen secondarily it is still there there's an 11 year old male injured in playing baseball two weeks ago he was pitching I don't know what an 11 year old is doing pitching but they all are these days I think we're overusing these children in some of these repetitive sports but this one was landed on the elbow when catching the ball so it wasn't while he was pitching and he's got posterior elbow pain so we'll cut him some slack there is the distal anterior bundle of the UCL there is a little slit right here hard to know whether that's just a recess or a tear because it's only about a half to three quarters of a millimeter I suspect it's a normal one but all the abnormalities are up here where the patient has a bulge a piece of bone there's swelling of the proximal UCL now this is a real proximal UCL injury with a bulge bone with diffuse swelling in the adjacent flexor pronator mass here's a 13 year old female gymnast with lateral elbow pain this one's interesting because she's got remember she's 14 look at her osteoarthritic spurring these gymnasts take an incredible beating on the balance beam and on floor exercise and unfortunately she's developed AVN of the elbow which almost always occurs in the trochlea not in the capitellum you get OCDs traumatic direct insults from impaction and valgus in the capitellum but the AVN occurs in the trochlea you see the sclerosis and the hyper intense reparative hyperemia around it with premature OA that is a potential career training problem let's turn our attention to the lateral muscles and tendons here's a patient with a lateral epicondyle tear now what's nice about this is one of the treatments for tennis elbow or lateral epicondylitis is to cut the common extensor mechanism so this patient has already done the job for us they've already cut the common extensor mechanism so there really isn't any treatment here other than physical therapy and to try and get the swelling and blood out of this elbow the other thing you should be doing is weighing in on the status of the radial collateral ligament which here's intact but here is not intact so it's an incomplete tear full depth there but incomplete tear the fibers that are more in the front are intact the ones that are more in the back are cleaved a little bit right there let's talk about the anterior tendons and muscles let's start out with the brachialis now we said the pronator teres has its origin from the coronoid the brachialis has an insertion on the coronoid there are superficial and d-pads the superficial head is larger and arises from the anterior lateral aspect of the middle third of the humerus and the lateral inter muscular septum the d-pad smaller arises from the anterior rectus and medial inter muscular septum the d-pad is slightly lateral to the superficial head by the way and it inserts on the coronoid process the brachialis has very broad contact with the capsule so in dislocations when the capsule is torn it is very common for the brachialis to be torn most of the time the surgeon will not try to repair the brachialis with sutures it's like trying to sew spaghetti so the superficial head has a circular terminus that inserts on the ulnar tuberosity the deep which is the main head has a terminal thin upon neurosis that attaches on the tip of the coronoid process and once again intimate contact with the capsule let's have a look at the brachialis here we're proximal here we're distal here's the big fat brachialis there's a little bit of the central superficial tendon there's the deep tendon it's a little bit wispy looking but it's going right on the tip right there there's the tip of the coronoid process and there's the slightly frayed deep portion of the brachialis here's a laid out view of the brachialis you can bend the arm and put the patient in the scanner in the mighty mouse position and here you're seeing very nicely the deep head of the brachialis as it attaches to the coronoid process this was a dislocator and there are areas of tearing involving the brachialis muscle here's another one this is a patient with a biceps injury it's very easy to confuse the biceps with the brachialis the brachialis goes to the ulnar the biceps goes to the radius so you've got to kind of tease them out the radius is on the lateral side so here's our biceps laid out there is a short head and a long head sometimes they insert together sometimes they insert separately the short head arises from the coracoid the long head from the superior glenoic tubercle you're more familiar with the long head they cross the elbow as a flat tendon and insert on the radial tuberosity you have a broad medial expansion right in your anti-cubital space this is known as the lecertis fibrosis and it merges with a fascia of the flexor tendons so injuries of the lecertis are pretty serious because they do involve some other structures as mentioned the insertion can have one or two separate heads for short and long and sometimes you have two separate heads 10% of the time most of the time though 90% of the time they join 6 to 7 centimeters proximal to the insertion I'm not so concerned with you today about learning which insertion is which on the radial tuberosity and distal to it because it's not that important and it doesn't happen often there is your biceps brachii it's starting to form a little bit attendant more biceps brachii starting to flatten out into the lecertis fibrosis don't confuse it though with adjacent vasculature here's the artery here's the vein brachial artery brachial vein some smaller vessels and of course here's your brachialis and on the medial side here's your pronator teres let's keep going sorry here is your brachioradialis my apology on this side is your pronator teres let's keep looking now there's your lecertis fibrosis flattening out not to be confused with the brachial artery and vein and here you are on the on the lateral side there is the brachialis inserting on the trochlea there is the biceps brachii inserting on the biceps lateral side medial side just to clarify that's your pronator teres that's your brachioradialis and the reason that's important is because you've got two heads of the pronator teres and you've got the deep head and the superficial head in between the two you're going to find the median nerve which is a pretty big structure on the medial side in the back you're also going to find the ulnar nerve and you'll see that a little better here coming up in a few moments and then here between this thick and fibrotic area of normal normal fascial tissue you're going to find not shown here because it's covered up by arrows the superficial and deep branches of the radial artery sitting between the extensor mechanism and the supinator more on that in a few moments here's a coronal projection showing the biceps brachii on the radius brachialis with its two heads going on to the to the ulnar so the brachialis has two heads and the biceps has two heads and you've got to follow them carefully because look how they come together that's brachialis that's biceps so you have to really tease them out on successive coronal projections there's an example of an acute biceps injury short axis axial long axis sagittal lateral view there is your biceps tendon it is already fused long and short head 6mm above its attachment this should come all the way down to the radial tuberosity it does not it's ruptured and there's your intact brachialis in the sagittal projection we've got a number of findings here the biceps brachii is diffusely swollen and bloody and fat it should go all the way down here even though you're not seeing the radius the coronoid tip looks perfect the superficial and deep fibers of the brachialis look perfect there's the attachment of the superficial there's the attachment of the deep but look at the lecertis fibrosis or biceps aponeurosis it's swollen it's a little bit frayed and there is a defect in it that's a serious injury here's another example of a biceps injury a little less severe here you can see the short and long heads and some swelling between the two evaluate for biceps rupture well it's not ruptured most of the fibers are still on but there is extensive peritendinitis around the two heads of the biceps one of the unusual examples where you can see the two heads inserting simultaneously here's another one even though it's not totally gone what's left of it is trash just a one millimeter little wisp of the biceps short head is all that remains in this case of a 54 year old man who reached out to catch a very heavy rack and then the swelling around it and then you would go ahead and follow it more approximately here's another one this one's quite easy I call this the cobra sign it looks like the cobra's getting ready that should be inserting somewhere down here the lacerous fibrosis has turned into dust I'll often refer to this as a pre-lacerous tear a tear where the fibers of the biceps brachii have retracted proximal to the lacerous as opposed to those that are distal or post-lacerous now sometimes in the lacerous it will fill with blood so don't confuse this with a mass or with a muscular structure or with a tophus or with a rheumatoid nodule this is blood from a rupture that fills the lacerous fibrosis which is housed in a very thin fibrous pseudo capsule and then there's swelling around it as well there's a 65 year old complaining of elbow pain going into the forearm there's a slightly different type of injury this is somebody with diffuse tendinopathy but that's not all look inside the tendon remember we said the tendons consist of subunits subunits are parallel to one another look at how disorganized on the T1 and on the T2 weighted image the interstitium of the biceps is so it would be really improper to call this tendinopathy it's more appropriate because of the loss of the internal anatomy to call this a scarred interstitial tear and then look at that defect right there there's also some substance of tendon loss let's turn our attention now to the posterior tendon and muscle groups the triceps there are insertions to the elecronon and the anti brachial fossa near the econius we have a superficial group that's the most important group a long head on the medial side and then a lateral head on the lateral side and then we have a deep head on the medial head which has a very short stubby virtually nonexistent tendon the long head is the famous one it comes off the infraglenoid tubercle the lateral head comes off the back of your arm just above the posterior lateral radial groove the medial head comes off the lower aspect of the humerus along the posterior medial radial groove so it's a short stubby little structure let's look from the back let's just take this image right here you are viewing from posterior so this would be lateral this would be medial here's a scapula to get you oriented there's your long head coming off the inferior tubercle of the glenoid there is your lateral head coming off the upper aspect of the humerus and there's your short stubby medial head that is virtually devoid of a tendon that is deeper here we have the long and the lateral head long head, lateral head and then the fan shaped attachment of such and then let's keep moving along here just in the interest of time here is the superficial group of the triceps which consists of the long and the lateral head I have them labeled with the yellow arrow and then here's the medial head look at the paucity of tendon intensity that one sees for the medial head which by the way rarely tears or ruptures it's usually the superficial component that evolves either with or without a piece of bone now triceps ruptures are rare they're less than 1% of extremity tendon injuries average age about 50 usually men sometimes they're taking cortisone or anabolic steroids and here's what they look like you're on one side of the elbow it looks pretty good because you're seeing one head you go to the other side maybe you're on the long head or lateral head side and you know you've lost most of the superficial tendon there's a few deep fibers that remain so what would you call this a partial depth tendon that's eccentric off to one side then you'd look at the corolla you'd say oh it's 50% from side to side you give a measurement of the retraction and you go on to say that the deep medial head fibers are intact so that's it's a little bit tricky if you don't know the anatomy here's another example of a of an upper extremity injury this time the triceps itself is still there all the abnormality is superficial to the triceps it's a T1 weighted image no that's not simple fluid that is dilute blood this is a patient with Morrell lavalade de-gloving syndrome the econius it covers the posterior annular ligament and attaches to the lateral elecronon and upper posterior ulna its origin is from a small posterior tendon from the lateral epicondyle the reason it's important is there's a variant called the accessory econius let's have a look short axis view from our total body atlas in MRI this is where lateral epicondylitis occurs here's our pronator teres with its two heads you can see the deep positioning of the median nerve you can see the superficial and deep components superficial and motor components of the radial nerve and then we've got the ulnar nerve sitting between some of the muscular soft tissues but I'm showing it for the econius which sits a little bit lateral to the elecronon but if you had an extra econius blue ball it might get in the way of the ulnar nerve especially if you're a little bit more proximal let's have a look we are a little bit more proximal right here this is the medial epicondyle there's the lateral epicondyle that's a T1, that's a T2 and there is your econius and we have twins we have an extra econius on the other side it's close and relationship to the ulnar nerve which is just a little bit swollen no it shouldn't have a little bright signal in the middle of it that structure by the way is the accessory econius and here's another example, different patient showing you a large accessory econius let's talk about some nerves and we'll start out with the ulnar nerve we already defined some of the anatomy and the superficial ligamentus component that forms the cubital tunnel and inside that tunnel is the ulnar nerve which happens to travel with a small recurrent ulnar artery and a little bit a little vein then superficial to that that ligament of cooper right there is this very thin wispy structure here which you can barely see called osborn's fascia cooper's ligament fascia lower of the cubital tunnel and then we've got these structures anteriorly which support the anterior aspect of the tunnel including the anterior bundle of the UCL and the common flexor mechanism here's a coronal look at the elbow there's your triceps tendon with it's fan shaped attachment and there is your ulnar nerve it should be pretty uniform in it's size when it goes behind the condyle it shouldn't go from dark to white to dark and on a T2 it should maintain a uniform intermediate signal intensity it should look nothing like this that's the ulnar nerve it shouldn't have this black band of fibrotic tissue around the outside it shouldn't have this disorganized this disorganized mixoid hyper intense look that looks like the nerve is going to explode any minute it's too big first of all the nerve should only be about 6 to 8 millimeters this one was 1.2 centimeters that's what cubital tunnel syndrome looks like here's a 32 year old man with a lecronon region pain and numbness in the forearm and hand I believe this was an MBA case yes it was and here's your PD spur now I don't mind on a PD spur if the nerve is a little bright it wouldn't bother me too much if that was a T2 it would bother me a lot but here's what does bother me look at where the nerve is positioned it's perched on the back of the ulnar it shouldn't be there it should be over here so it's in the wrong position and then look at its shape on the T1 it's got this really weird oval shape and it's perching out of its groove and by the way we call it a groove because it should be a receptacle instead your convex back here so you've got a deformity of the postural medial aspect of the humerus which is contributing to this what's the treatment for this to lice Cooper's ligament to lice Osborne's fascia and to do nothing do not touch that nerve that nerve does not like to be manipulated by man or woman or woman let's go up a little bit higher I don't mind that the nerve is a little bit swollen right here sorry that's a little bit hyper intense because it's a pd fat suppression but I do mind the size it should be 6 to 8 millimeters and it's a lot bigger than that let's turn our attention now to the enterosius nerve which when insulted forms the syndrome of kilo and nevin now you can hardly ever see this nerve there's a differential diagnosis for it but it's a very easy diagnosis you see this almost triangulated pattern of neurogenic edema anterior to the enterosius membrane this nerve being a branch of the median nerve how about the radial nerve this one's oft overlooked the poor kissing cousin injuries of this nerve and this tunnel are known as the supinator syndrome the posterior interosius nerve syndrome they have pain in the dorsum of the forearm posteriorly and they have gradual weakening of the fist they'll also have a positive tenel sign so if you tap on the enter aspect of their of their forearm they're going to get some discomfort here's an example of the motor aspect of the radial nerve you can see it with a decent enough image quality you've got a little bit of fat on either side you've got a little bit of dark fibrous tissue right here I don't know if you can see it I'm going to put an arrow on it with my pen just so you can see it this right there right there, right there that is known as frosius arcade now here's a very unfortunate case you are looking at a coronal projection for those of you who are quick on the trigger there's the liver, there's the kidney so it's an AP projection the lungs over here you're looking at an AP orientation and sadly this is not an artery or vein this is a radial nerve now that's the normal size of the common radial nerve that is a huge radial nerve diffusely infiltrated by IgG mu in a patient that suffers from an autoimmune a perineoplastic phenomenon in which the nerves got attacked very similar to the syndrome known as poem syndrome polyneuropathy organomegaly endocrinopathy m-spike and skin lesions that we see with myeloma this patient had an unusual form of lymphoma that eventually entered her superior and recurrent laryngeal nerve and took her life for a short axis view no that is not a vessel that is the radial nerve there's a 46 year old who had biceps repair six weeks ago and now has posterior interosseous nerve syndrome by physical exam by a hand surgeon now sometimes what they'll do to reattach some of these tendons is they'll anchor them through the bone and put a flat object that may be made of acrylic and they'll pull the strings of the suture through and tie them on the other side to make sure that everything is snug so this is the radius this is the ulna and here is our supinator that's Frosius Arcade so we know that the radial nerve structures are going to live in here somewhere even though we don't directly see them now take a look at the water weighted image this geographic muscle by muscle area of edema corresponds exactly to the motor distribution of the radial nerve which you obviously have to memorize or learn and then once you know what the procedure was and that this is a complication of that procedure you're going to make the correct diagnosis then finally not to be forgotten is the median nerve we got our ulnar nerve we got our radial nerve with its superficial and deep motor division but now we have the deep and superficial heads of the pronator teres and the median nerve let's have a look at this 82 year old man concerned for biceps injury he doesn't have a biceps injury in fact the biceps was absolutely fine but his pronator teres and flexor pronator mass has this large object associated with it that's an artery right there we've got some other blood vessels and tendons in the neighborhood but where's our median nerve our median nerve is getting squished right here right there is the median nerve so this is somebody that suffered from pronator teres syndrome there is our hematoma involving the flexor pronator mass look at the signal of our median nerve which is one of the bigger nerves in the body it looks almost like a vein it's too big it's too bright this is pronator teres syndrome also known as honey moon paralysis you know because sometimes when you're on your honey moon and you fall asleep and your new partner's head is on your arm you don't turn to them and say darling your head is too heavy you just go to sleep and when you wake up you have honey moon paralysis here's another example of somebody with a displastic large median nerve but look at the object arising from the median nerve that has a little bit of internal speculation and is round consistent with a median nerve schwannoma so we covered a lot of ground today we talked about the skeleton and showed you some really critical bone abnormalities like the Osborn caudal lesion the sacs fracture of the elbow the coronoid fracture we talked about the ligaments how there are two major ligaments on the lateral side and one major ligament on the medial side with two minor ligaments that help house the ulnar nerve we spent some time on the common flexors and extensors we showed you the short and long axis of the biceps describe their anatomy we showed you the two heads of the brachialis we showed you the three heads of the triceps one of which is usually not consequential the medial head and we finished with a flurry talking about cubital tunnel pronator terry syndrome the posterior interosseous nerve syndrome or the syndrome of frosius arcade and the anterior interosseous nerve syndrome also known as the syndrome of kilo and nevin at this point I ran just a little bit over to take some questions perfect I do see one question in the Q&A for you right now and I'm sure a couple others will pop in do you see that button on your end or do you want me to read you the question let's see it says can we get a certificate after this webinar do you see one that says open on there open there's one question can you read it to you pardon would you like me to read it to you perfect do you see one that says open for MRI elbow okay and the same question for the ulnar nerve well for the ulnar nerve you've got to have one critical sequence and that is high quality axial imaging and I like to have a T1 and a T2 spin echo I find the proton density axiol spur less valuable because the nerve is always going to be bright you're looking for the caliber of the nerve its consistency its position in the groove I don't want to see the nerve go light to dark to light I like to see it have a homogeneous gray signal intensity the other projection that's useful for the ulnar nerve is the coronal projection you kind of follow the nerve down to the epicondyle you lose it and then you follow it down again why do I like that because that will help me see if the nerve goes from thin to fat to thin again so a caliber change is really important not so much behind the epicondyle but if I have a caliber change above the epicondyle or below the epicondyle I get worried now for my standard elbow I like to have at least one PD fat sat and at least one T1 and at least one T2 now where am I going to put these it depends on the diagnosis if I'm looking for medial or lateral epicondylitis medial or lateral elbow pain I'm going to lob most of my sequences in the coronal projection with a few axials I'm not going to focus so much on the sagittal if I'm worried about the biceps and the triceps I am always going to have a lateral projection and I like to have a lateral T1 T2 and PD so it depends on where the pathology is if the pathology is in the front and the back the sagittal and axial are going to be your friends especially the sagittal if the pathology is on the sides then the coronal and to a lesser extent the axial are going to be your friend any other questions yes we have a few in here for you eventual birthday do not have synovial lining correct adventitial bursae adventitial bursae which are also known as eventual bursae because they eventually form usually you see those under your toes especially if you're a high heel wearer you get a pressure lesion which is basically a fibrous callus most common under the 5th and under the 1st eventually that callus will hollow out and it will fill with fluid so you're surrounded by this dense thick fibrous tissue but there is no synovial lining next question all right the tear of lateral and long head of triceps do you call it total triceps tear that is a very good question if you tear the lateral head and the long head do I call that a complete or total triceps tear I do because I know in my heart that the medial head just about never tears so if I lose both those structures and they're retracted I will call it a full depth full width tear and then I will go on to specify involving both the lateral and long heads now in the rare event that I have also torn the medial head I'll then say separately that the medial head muscular bundle with its short tendon is also disrupted so I'll leave that as kind of a separate subject that's just how I do it great question okay this one is the trochlea is for the AVN and the other lateral side is for what the trochlea is for AVN and the capitellum is for osteocondrol defect usually seen with valgus extension overload next question all right this one looks like the last one in the queue right now can I briefly explain lasardis fibrosis syndrome at the anterior face of the elbow sure can I briefly explain lasardis fibrosis syndrome at the anterior aspect of the elbow so the lasardis is attached to fibrous remnants of the common flexor and a little bit to the common extensor so sometimes those attachments will get interrupted you'll get micro tears you'll get inflammation and swelling and the lasardis becomes a little bit hypermobile and you'll get pain in the anti-cubital fossa and you'll see a little bit of swelling there next question all right I saw one more to pop in when would you use GAD for the elbow when would I use GAD for the elbow usually when I've had too much tequila I will give GAD for the elbow I hardly ever give gadolinium now if I have a lesion that's a cystic lesion or a micsoma or a schwannoma and I need to see enhancement then I will give gadolinium I rarely, and I mean rarely will put gadolinium into the joint it's an easy arthrogram to do why might I do it I've got clicking or catching in a high performance athlete and I have not come up with an explanation on a non-contrast study in that case I will then introduce gadolinium into the interarticular space to see if I can find a plica or a nasty fringe or a body all right those are all of our questions today Dr. Pomeranz thank you so much for taking the time to give us this great lecture and be with us today it's been a pleasure thank you all have a great day and thank you so much to everyone else for participating in our noon conference you can access the recording of today's conference and all our previous noon conferences by creating a free MRI account be sure to join us next week on Thursday April 25th at 12 p.m. eastern where Dr. Maria Cortes will deliver a lecture entitled acute encephalitis you can register for it at MRIonline.com and follow us on social media for updates for future noon conferences thanks again and have a great day