Computer generated transcript

Warning!
The following transcript was generated automatically from the content and has not been checked or corrected manually.

All right. Listen, welcome to you guys. It's a pleasure to have you all here. It's nice to be able to talk to you all. Uh We'll keep this pretty informal. So please feel free to chime in uh with questions as we're going through cases. Uh you know, ideas, if you're, you are wondering about it, more than likely somebody else might be as well. So please feel free to just uh to pipe up and uh you know, if we're, you're interrupting me, that's really not a big deal. So, uh my name is Cooper Dean. I'm one of the musculoskeletal radiologists here at UF. I'm the program director for the radiology program, uh which is super fun. Uh It's a pleasure to speak with you guys. So we'll go ahead and get started. So first case, uh let me see here, we have three images of what it's probably the long finger. And so you can see on the pa the posterior to anterior dorsal and palmar view right here. Really, I think most people look at it and say nothing's really wrong. You know, not even only, you know, there are soft tissues falling there, but it's pretty hard to appreciate along the distal interphalangeal joint. And then on the oblique view, which is rotated about 45 degrees. Once again, really not much you can call. However, on the lateral projection right over here, you can see that clearly, there's an abnormality. It's an oblique intraarticular fracture involving the dorsal base of the distal phalanx right here. And you can see there's a couple of millimeters, probably three or four millimeters of distraction along the fracture plane. So this is a classic example of an entity that you're gonna encounter all the time in sports medicine. It's called a mallet finger. Uh also known as baseball finger, usually in resulting from an impaction injury onto the di distal phalanx. And the idea there is your extensor tendon inserts right onto that base and it just pulls off that little chip of bone. Uh You can have equivalent injuries that might injure the tendon or they might be just be osseous. And here's a diagram that demonstrates that. So your extensor tendon coming down along the finger and certainly onto the dorsal base and it just matters what's going on with the bone versus the tendon as the regards to with regards to which structure gives. So if the bone is weaker, the bone gives the extensor tendon is weaker, the tendon gives. So just a demonstration here through a diagram and an x-ray, a lateral x-ray just showing you the pathology of of the mallow finger moving on here. Uh We have two views of a hand. So we have a pa or a posterior to anterior view of a right hand and then an oblique view of the right hand. And just going through the anatomy, we have a distal radius. We have the normal appearance of the distal radial articular surface, the distal ulna, the ulnar styloid right here, the distal radial ulnar joint, which some people call the Dr UJ right here. Uh Then you have the bones of the wrist. So we have the scaphoid, the lunate, the triquetrum and the pisiform, which is superimposed over it. You have the trapezium under the base of the thumb. You have the trapezoid articulating with the index finger metacarpal. You have the capitate right here. One of the larger bones of the carpus, the wrist articulating with the long finger metacarpal. And then you have the hamate which articulates with both the ring finger, metacarpal and the little finger metacarpal. You'll notice that don't number of the fingers. That's one of the things to think about. Just when you're in your notes, just give it a plain name. So the thumb, index of thumb, index finger, long finger, ring finger and little finger and everybody will know exactly which finger you're talking about every time. Uh The problem is people run into sometimes is if you say first or second finger, you know, uh there's uncertainty whether you're referring to the thumb or the index finger. So if you just all the hand surgeons just give it a plain name and everybody knows exactly which finger you're talking about. So, something to think about and with the understanding that clarity is very important with our communications amongst ourselves. So then uh the question is, which is abnormal. So most of the bones in the hand here have a nice, smooth, flowing, gentle curves along their uh edges along their cortices. When you get to the little finger though, you know there's a sharp angle right here at the neck of the little finger metacarpal. OK. The abnormality is much better demonstrated here on the oblique projection. You can see we have a transverse fracture going through the neck of the uh the little finger metacarpal and then you have impaction. OK? So there's four shortening along the fracture and you also have apex angulation. OK. So there's an angle right there. And so there's two different ways of talking about this. You need to talk about what direction the apex of the fracture is pointing. So in this case, it would be dorsal and ulnar apex angulation so that the apex of the fracture, the peak of the fracture is pointing dorsally and towards the ulna. OK. And, and that's another thing is once you get past the elbow, we don't use medial or lateral because you can force, you can uh supinate and pronate your forearm. So you can sit there and flop it, you know, front to back. Um You know, if you sit there and put your palm up, pull your palm down, it's all relative. So we don't use medial or lateral distal to the elbow. We always talk about uh anatomy or pathology that's on either the radial side of the forearm, wrist or hand or finger or on the ulnar side of the forearm, wrist, hand or fingers. So terminology is helpful in this case. And then same thing dorsal and palmar is another um two important terms that we talk about whether it's in the dorsal surface or the palmar surface. So in this case, transverse fracture, little finger metacarpal better demonstrated on these focused views of the little finger. So, but they demonstrate the transverse fracture line, you can see the fracture has a nice crisp, sharp lucent margins. So we know that this is an acute or early subacute fracture has not had time for the body to try to heal it. And it is a classic example of, you know, uh so called boxer fracture, fifth metacarpal fracture, little finger metacarpal fracture, usually fractures the metacarpal neck, classic ulnar and dorsal apex angulation. The fracture usually classically is outside of the joint with regards to it does not communicate with the articular surface. Uh It's usually young males who punch things that they shouldn't be punching. Um So whether it's, you know, a wall, a sign, a street sign, uh somebody else on a busy weekend night. Um You know, you, you're gonna see a lot of these when you're a radiologist and when you're a sports medicine doc, so you can get used to see them equivalent injuries happen, happen at the proximal margin of the little finger, metacarpal and may or may not go into the fifth CMC joint. So yeah, you know, I say fifth or little finger, MCP or a little finger just cause that's unambiguous. Everybody knows which finger you're talking about. I had a quick question. Yeah, go ahead. Um I think you might be about to answer it. Actually, I was wondering when it comes to like the carpal bones. Um You know, I know a few people have like pneumonics and stuff they use like what do you use to kind of like orient yourself and know which carpal bone you're talking about? Yeah, that's fine. That's perfectly good question. Uh You know, there's all sorts of pneumonics that are out there uh for me at this point, like, you know, I've been looking at them so long. You just know and uh probably for you guys, after we talk about this for a few minutes, you're gonna have uh you know, a better grasp on it. OK. So recall that once you along the radial side of the wrist, on the proximal carpal row, OK. The proximal carpal row, the distal carpal row out here. OK. Remember carpus is another term we use for just talking about the wrist. Uh The scaphoid is on the radial side of the wrist and traverses both the proximal carpal row and part of the distal carpal row. And you have the lunate, which is in the middle of the proximal carpal row. Then you have the triquetrum out here and you have the pisiform right here, ap shaped bone. Remember that the pisiform is on the palmar side of the wrist and it's actually a sesamoid bone within one of the flexor tendons on the ulnar side of the wrist, the flexor carpi ulnaris, the flexor on the ulnar side of the wrist out here. Uh You know, there are sesamoid bones. You guys might be aware of the, you know, patella is another that's a, your kneecap is a big sesamoid bone. Uh It's hard to when you think about it, you're like, wow, that's a big sesamoid bone. Yeah, that's what it is. So it's a bone that resides within uh a tendon uh at a fulcrum point or at a point where it goes over a surface uh going out to the distal carpal row, the trapezium under the thumb, trapezoid index finger, capitate, little uh sorry, long finger, hamate, ring finger and little finger. And then you have the hook of the hamate right here. Uh which you can see which projects on the palmar aspect of the hand. Uh We can see the distal radius has two smooth fossa right here and each of those articulate with their respective carpal bone. So you have the sca fossa and the fossa right there. Those little dips and yeah, it's good. So just anatomy recap before we go on to pathology. So we have a focused pa view of the right wrist. You can see this patient is they're done growing. So their distal radial piscis and distal ulnar fiss are both closed. So the growth plates are closed. So this is probably a late adolescent. You can see that the, you know, the fiss is just now scar, you know, closed down. So they're probably in their late teens. And the striking abnormality in this case is subtle. It's non displaced, but there's a linear lucency traversing the waste of the scaphoid right here. So classic injury, scaphoid waist fracture, you can either have fractures of the proximal pole, the waist or the distal pole or the bony projection off the palmar aspect of the tubercle. But in this case, it is a classic scaphoid waist fracture better demonstrated on this cone down pa view, but also on this view right here, which is a so called SBO view where we tilt the hand as far as you can toward the little finger. So everybody take your, you know, right hand, your little finger and bend it away from you toward the little finger and then try to dorsal flex the wrist. So it flex it dorsally. That's the position we're trying to get the wrist into for this in order to minimize the overlap of the other carpal bones here uh with their esca in order to demonstrate the anatomy here. So best demonstrated on that projection. So Sapho waste fracture, non displaced minimal comminution. OK. So there's more than two fragments, just a tiny third fragment right here. The important thing here is that it's non displaced and this would likely heal well with conservative management. Um We'll talk about that in a second. So, escape fractures are the most frequent carpal bone uh to get injured. Remember that the escape spans both the proximal and the distal carpal row. The thing about the scape is you have a recurrent blood supply. OK. So the vasculature comes in from the distal pole and goes to the proximal pole. So if you have a fracture across the waist or particularly the proximal pole, you can jeopardize the blood supply to the proximal fragments right here. And if you don't get good bone here that bridges along there and revascularize that proximal fragment over time, you can necrose that fragment and it will just crumple down and wither away. And then your carpal mechanics are uh shot and your wrist. Um you know, uh the risk of uh the risk of wrist, osteoarthritis goes way up. So the closer your fracture plan is to the proximal pole, the greater the chance of osteonecrosis to that fragment. And the closer that those patients need to be followed. Just some diagrams here just showing you a tubercle fracture, waist fracture. And then just some diagrams talking about the osteonecrosis and the jeopardy along the proximal fragment. So, escape boid waste fracture. Different example here uh sca waste fracture once again, traversing the waste of the scape. And in this case, uh used a very simple, well, uh I say simple, but it's an elegant way of snugging and compressing those fracture fragments together. This screw is completely contained within the scaphoid. And you'll notice that it's hollow you along its center. Uh so that allows it to be placed over a guidewire in a retrograde fashion. So from, from distal to proximal, so retrograde and you also notice that the threads along this side of the screw are thinner spaced than on this side of the screw. And what that allows for is when the screw gets placed, this is called a gradient tapered compression screw. And by virtue of the differential spacing of those threads as they put that in, it's when tend to snug those two fracture fragments together. And so, uh you know, the engineering that goes into designing things is really these particular, you know, pieces of hardware is really elegant and it's beautiful and this screw will live in this bone forever. And this patient is going to heal their scapoides, gonna be fine and they're gonna do just what uh you know, they're gonna do perfectly well. So it's a really beautiful, simply constructed uh elegant solution to what can be a challenging problem uh for an orthopedic surgeon prior to this uh type of hardware, uh moving approximately along the upper extremity up to the elbow. In case we've got a lateral radiograph right here. And you can see these are two different patients. So this is a normal lateral radiograph. OK. You've got the distal radius, you've got the electron on fossa right here that dip along the distal humerus. You have your coronoid fossa right here where your coronoid process comes up. And um you know, goes into that fossa when you're fully flexed. When you're fully extended, the electron goes into the fossa right here. So the electron goes into that fossa depending on whether you're flexed or extended. You can see this patient has open feces. So they're somewhere in their, in the middle of their growth spurt. Uh Right now, likely, you know, they're a child or early teenager. Uh Those feces have not yet closed. In contrast with this patient over here, which is older, their feces have closed. OK. Also, you'll notice um between the major difference between these two right here is if you look right here, you can see a triangular fat pad that's sitting within the coronary fossa and you cannot appreciate a fat pad posteriorly, that's normal, normal. OK. On this side. However, uh you can see that the fat pad has been pushed out proximally and anteriorly and the posterior fat pad has been pushed up and out as well. Then what that tells us is that this patient's joint space is just normally filled with this tiny trace amount of fluid to lubricate the articular surfaces, the cartilaginous uh articular surfaces. This patient has a joint effusion that's pushing those fat pads out of their normal position up and out the so called S signs. A really nice demonstration right here and what that tells us that they have a joint effusion. And in a patient coming in to uh presenting, you know, on x-ray with an elbow joint effusion that's considered an intraarticular fracture until you prove it's not. And the idea there is they have, they, you have to presume that they have a subtle fracture somewhere that's allowing blood and potentially fat from the marrow space of the bone to get out into the joint space and to uh shift those fat pads around. So positive cell sign intraarticular fracture until you prove it's not. You guys all see that? All right, I see a couple of nods. All right. Awesome. And so what kind of are the next steps in like proving whether it's a fracture or not? Is it just you kind of treat it as if there is a fracture or? Yeah, it depends on uh you know, as always, uh is your management gonna be ba uh gonna be changed by uh a, a different test? So, if you're just gonna treat them like a fracture, then likely just to treat them like a fracture and bring them back and consider doing radiographs uh when they repres in, you know, in 10 to 14 days after immobilization, uh alternative, like I said, if you're concerned for potentially something that's uh deforming or displacing an articular surface, you know, a CT would be a very reasonable examination to order in order to uh evaluate for intraarticular extension or articular surface incongruity. So if there's a step off of any of the fracture fragments, that's something you could look for. So a different patient here, uh so an ap view of the elbow, so you can see the medial humeral epicondyle, the trochlea uh yeah, the trochlea right here, the electron articular surface, the capitellum right here and then the radial head. And you notice that there's a sub linear lucency along the radial head better demonstrated on the lateral radiograph right here. So you have a mildly impacted mildly distally displaced fracture involving the volar the palmar aspect of the radial head right here. So a radial head fracture, uh acute fracture of the joint infusion cone down view that are demonstrating a fracture right here along the radial head and then like we were talking about. So ct better demonstrates the morphology of the fracture planes here. So this image right here is a slice that's been reformatted to parallel the articular surface of the radial head. And you can appreciate the fracture planes along the radial head right here. So you can see there's a dominant plane and a smaller plane and it involves about 40 or 50% of the articular surface of the radial, not much displacement, maybe a millimeter or so of impaction. So my thought is they would probably just let this heal by secondary intention. So just let it heal on its own without intervening or reducing and putting it in pins. But uh to your point, Amanda, you know, the CT better demonstrates the morphology of the fracture plan in this case and allows for uh decision making based on those findings. So they just let this one heal by secondary tension. And you can see over time, this is about probably three weeks later, you can see that there's this mineralization that's bridging across the fracture. The fracture plan here, that's bridging, mineralized callus that it represents normal healing in somebody that's got a well managed fracture. So that's what we're looking for over time is bridging mineralized callus that over time as the weeks and months pass is going to remodel back into bone and then over time that's gonna be reshaped in response to the stresses that are being applied to this bone. So uh that's normal bone healing commonly, you see that about three weeks in normal healthy people and those are two really important words um to, you know, uh apply to that caveat. There is you know, we also, you have, see a lot of people that are abnormal and unhealthy and so there's any, you know, there's a galaxy of things that can adversely affect the way somebody heals. Um, you guys, you know, uh, we put out to the crowd, what are some things that can delay the rate at which you heal a fracture? Mm. Or something. A type of like osteoporosis, osteopenia type of. Yeah. Sure. So any anything. Yeah. And so people with metabolic bone disease, uh osteoporosis. Absolutely. Uh Just being older. Ok. Uh being an elderly person. Ok. People with diabetes. Ok. It is gonna adversely affect their healing, smokers. Ok. People with poor vasculature and vascular, peripheral vasculopath. Um people that are alcoholics or people that have uh terrible diets. Um people that have immune compromise of some sort. So people with HIV, OK. People who are undergoing uh chemotherapy. Ok. For cancer, you know, it's gonna something that's going to adversely affect their, their immune system and their healing people are on chronic steroids. Ok. That's gonna be another thing that delays their uh inflammatory response and healing. So uh then you get into people with abnormal livers who have abnormal protein synthesis or abnormal kidney function. So they have abnormal calcium and phosphate metabolism and uh balance in the body. So like I said, any, any number of things can adversely affect somebody's healing. And so it's just important to be aware for that. Uh be aware of that when I say, you know, in about three weeks, that's in normal healthy people and taking the patient's clinical context into consideration is really important. All right. So the radial head fracture is pretty common, about 20% of elbow injuries usually FH so fall on outstretched hand, you'll see that uh acronym all the time. Uh And it's usually related to axial loading onto the radial head, commonly isolated injuries, but you can have injuries uh on the forearm. So you can injure the interosseous membrane between the radius and the ulna, uh or you can propagate that out and, and, and disrupt the Dr UJ out by the wrist. You can also be associated with elbow dislocations in any direction and then uh injury to the collateral ligament complex is either on the medial or lateral side of the elbow, all righty, uh normal shoulder here. So just uh before I show you abnormal, it's helpful to have an idea of what normal looks like. So we, we have a nice ap view of a shoulder. So, anterior to posterior, we have the chest wall right here. The scapula right here, the glenoid, the articular surface of the scapula, which is almost like a golf tee and it'll look more like that. In the second one, I show you uh you got the coracoid process that sticks off the front of the scapula. So it looks like a thumb on the lateral projection. Uh Corax is Greek for crow and somebody decided that looked like a crow, I think sitting on a fence or something. Uh ok. So that's the coracoid process. You have the scapular spine, the acromion, the acromioclavicular joints, the ac joint right here, lateral clavicle, midshaft and then medial clavicle over here which articulates with the um manubrium or the sternum at the, at the sternocostal articulation. You have the humeral head, you have the lesser tuberosity, which is right there. You have the greater tuberosity right here, humeral neck. So the metastasis and the diaphysis, uh this view right here is angled slightly differently such that we are looking down the articular surface of the glenoid right here and you can see that so you can appreciate the articular surface of the glenoid, the coracoid process sticking out like a thumb over the front of the shoulder right there. And then the humeral head, which is centered on the glenoid. And on this view, the gray view, uh you get a better appreciation for the lesser tuberosity and the greater tuberosity of the humerus of the humeral head right there. This axillary view is basically, if you were to take your right thumb and point it up your left armpit, that's the direction of the beam. OK. So we're looking basically up somebody's armpit and I always like to orient uh like orient the images like this because that's the way you look at it on a CT and So for me, that's the way it's the easiest way to make sense of the anatomy. So here's our scapula, that's our shoulder blade right there. This is the scapular spine coming off the posterior aspect of the scapular body acromion, the ac joint, the clavicle coming over here and then you have the coracoid process sticking out like a thumb off of the anterior aspect of the scapula. And then your glenoid, which on this ax injection looks like a golf t like I talked about. It's also easy to appreciate. You know, you look at here and this is not a deep cup for the humeral head to be on there. And it gives you an appreciation for the inherent instability of the gleno, the glenohumeral joint, the shoulder joint. Ok. So the stability of the shoulder is really, really predicated on the integrity of all the soft tissue structures that support this, that support this joint. So the rotator cuff the capsule that runs from the glenoid to the humeral head and then all of the thickenings of that capsule, the glenohumeral ligaments. So there are a lot of structures that help to stabilize the shoulder. And then you get into the labrum that runs along the periphery of the glenoid, uh a little lip of la uh fibrous tissue or fibrocartilaginous tissue that runs along the shoulder along the glenoid, excuse me. So, normal uh axillary projection, humeral head is centered on the glenoid right here. So the golf balls on the teeth contrast this with our abnormal case here. So we see the orientation of the humoral head with respect to the glenoid is frankly abnormal. In this case, you can appreciate that the humeral head is inferior to where it should be, but it's also medial. So inframedial and this is a classic appearance of an anterior and inferior dislocation of the humeral head with respect to the glenoid with the humeral head residing in what we refer to as an infra coracoid position. So it's the in underneath the coracoid right here. You can also appreciate that there is irregularity along the poster lateral aspect of the humeral head right here and that there's bone fragments out in the joint space and likely bone irregularity along the anterior aspect of the glenoid. And these types of injuries are part and parcel with anterior shoulder dislocations and we'll talk about those in a second. So a dislocation is any time you have complete loss or 100% loss of articulation between two articular surfaces. In this case, the glenoid and the humeral head into your shoulder dislocations. If you're a card counter in Vegas by far is the most common. So, you know, it's almost 100%. So 97% we talked about the directions that the humeral head goes anteriorly inferiorly and immediately. So subcoracoid or infracoracoid position, posterior dislocations, conversely, the humeral head usually directs, goes straight back and everybody always remembers, you know, electrocution uh and seizures is like, you know, sort of the exotic and unusual reasons that people get posterior uh shoulder dislocations. But we commonly and people that are playing like a contact sport like football and somebody takes a helmet to a shoulder and it kicks the humeral head back. So, uh everybody else remembers those sort of exotic and sexy stuff like, you know, seizures and electrocution. But, you know, for what you guys are gonna be doing, it's likely gonna be somebody taking a direct blow and get thrown back posteriorly. So the injuries, the bony injuries that we talked about the hill sacs and impaction fracture usually occurs on the supra, posterior or posterior, lateral aspect of the humeral head. And the bony bank heart lesion is seen on the axoid projection and involves the anterior Antero inferior rim of the glenoid. So here we can see a hatchet type deformity, a hill sacs and pat and fracture a little bit harder to make out on the AP projection. And then here we can see this is an axial MRI image of a left shoulder. So anterior is this direction, posterior is this direction you see the humeral head and we can see the glenoid right here, which should look like a golf t but you see there's a defect right there through the anterior aspect of the glenoid. So they have a non displaced glenoid rim fracture which involves the labrum right here and the bone and the cartilage. So there is a bony bank le it's non displaced. In this case, they likely let this heal by secondary intention. But for us characterizing how big that fracture is, how much of the articular surface is involved. And the degree of displacement is really important and has implications for how they're going to manage this. Uh questions on shoulder dislocations before we move on to a knee. All right. You guys hanging with me. You guys doing? All right. All right. I see some smiles and some mouth. I'll take it good. All right, a little bit more. So um this is this is some great stuff right here. So super subtle uh findings right here. So we have an ap view of the knee and we have a lateral radiograph of a knee. OK. We have the distal femur, the patella right here. Superimposed of the distal femur, medial condyle, lateral condyle, proximal tibia, medial tibial condyle, tibial eminence, lateral tibial condyle, fibular head, fibular neck, proximal metastasis of the tibia, proximal diapsis on the lateral projection. You see the patella at a much better advantage. OK. And normally you should just have a tiny sliver of l of opacity right here, which would be a the normal amount of physiologic fluid. In this case though, we can see there's too much fluid here on the lateral radiograph. This is a joint effusion in a patient that had an acute injury to their knee. And there's also two other really subtle important findings on this case. Uh We have to blow it up in order for those things to become apparent, but there's one and there's the other and I'll sh I'll show you here in a second. So on this cone down image, you can see there's a tiny non displaced fracture along the lateral aspect of the proximal tibia. This is a classic injury. Uh it's called a Sagan fracture. It's like second, but with a G instead of ac. So the Sagan fracture highly associated with internal derangement, in particular acute ACL injuries. So, if you can remember, so, you know, take home point, uh that's a big one today, a Sagon fracture and then the the other abnormality is the second dip right here along the articular surface of the lateral femoral condyle. It's normal to have uh condylopatellar sulcus here, but having a second one or having a very deep condylopatellar sulcus on the lateral femoral condyle is abnormal. So there's our Sagon fracture, there's our joint effusion, there's our impaction injury along the lateral femoral condyle. Uh Next day, your choice. In this case, we're thinking internal derangement. What do you think would make the most sense for looking for cartilaginous ligamentous or tendinous injury? Ry Mr cause we're interested in soft tissue pathology and there's a lot that can go wrong in the knee. And MRI is outstanding for looking at those things. So we have an uh um we have a Coronal image right here of a knee uh in this patient. And you can see all the fat is dark, OK. It's a fat suppressed image and you can see the fluid in the knee is bright. So there's a fluid sensitive sequence. It's just a nice term that covers lots of different types of uh Mr sequences. It's a fluid sensitive sequence. And you can see here there's a bright spot on the lateral thermo condyle and a tiny bright spot here along the deep to the Sagon fracture. On the lateral uh tibial metastasis. You can also appreciate their soft tissue edema along the all the lateral side of the knee. Uh and you can also appreciate the articular cartilage right here. So you can see our cartilage layers along the lateral femoral and tibial condyles, medial femoral and medial tibial condyles moving to a sagittal image right here. So we're looking at the knee from the side, it's like a lateral image uh or a lateral radiograph. Here's part of the patella or lateral femoral condyle. There's our focal impaction injury with edema deep to it and subtle impaction injury back here. So in order for this part of the bone to uh gotten bruised, it usually hits this part of the knee. So the tibia translated anteriorly, the posterior part banged right here and then it recoiled back or uh uh you know, ended up going back. It's physiology position. And in order for that to happen, almost certainly, it's related to the ACL, either partially tearing or completely tearing on this image. A sagittal image through the middle of the distal femur, you could appreciate that the ACL which should normally go from the posterior aspect of the intercondylar notch to the anterior aspect of the tibial eminence and should be contiguous fibers here, it's completely blown up. So complete disruption of the anterior cruciate ligament. ACL PCL is intact, just we don't see all of it here. We gonna appreciate the extensor mechanism of the knee, the patella, the patellar cartilage and the joint fluid right here. So a nice example of uh ACL injury, this is what they normally look like. So we usually can make out discrete uh fibers following their expected course. ACL injuries are super common about 100,000 cases per year in the U usually sports related but not always remember that the ACL resists anterior translation of the tibia. And that's what you guys look for when you're doing your, your sports exam. So your, your uh anterior drawer and your anterior allotment exam. So, injury to the ligaments are associated with excessive uh anterior tibial translation. That's when we injure them. But it can be, you know, either deceleration change in direction like doing some sort of cutting uh while they're running or just abnormal planting or landing of a foot. Uh The common thing that people used to learn was un the unhappy triad of or Donohue or o'donohue's unhappy triad. Uh This is definitely kind sort of the older school of uh discussion with regards to knee injuries, you know, where the ACL tear is thought to be associated with NCL and medial meniscus tears. But subsequent, uh research has demonstrated that due to the uh proposed mechanism on on the knee mechanism of injury, that lateral meniscus injuries are actually more commonly associated with acute ACL injuries. And you can sometimes get medial meniscus injuries. But those are usually in conjunction in association with the lateral meniscal injuries. I recall that the mechanism that we talk about for acute ACL injuries often follows but not always. But uh a common discussion is the pivot shift mechanism. OK, where we have a pivot which is the valgus stress. So, valgus with the distal segment goes lateral or away from the middle line of the body. And then you also have the shift, which is the anterior tibial translation. So the pivot and the shift components and then you may or may not have internal rotation of the tibia. So uh when you have a pivot shift uh mechanism of injury, both the M CL and the ACL are under tension and that's when they're at greatest risk for tear because you're taking them to the edge or possibly uh beyond their physiologic limits. Um And then you can get meniscal tears related to the forces across the knee, I won't believe that. So direct IMA we look for about the direct and uh indirect imaging findings of ACL injury. So direct would be abnormal signal and abnormal morphology of the ACL or you can just see Frank fiber disruption. So if they're frankly discontinuous, like the example I showed you, obviously, that's uh evidence of an ACL injury. ACL should um converge with the line that parallels the roof of the interco notch, so called Blumen Sats line, which it does in this case. But in our case, before it paralleled the Blumen Sats line, which is abnormal, you can also have indirect signs of uh ACL injury. So kissing contusions like we showed in our case where you have bone bruises or fractures and then a joint effusion. But anytime you see a joint effusion, especially in a knee, you gotta think about internal derangement uh and consider proving it. Um you know, with some sort of study. All right, and I'll sort of bear that off. So when we talk about ACL injuries, uh historically, I've used grading. So grade one sprain, um grade two partial tear, low grade, less than 15% torn, high grade, graded 50% and then three b complete tear classically, anybody with 50% or higher tear uh is thought to be a candidate for recon uh for ACL reconstruction, but it totally depends on the age of the pain and what we're expecting them. And what they wanna do. So PT for low grade tears, high grade for complete uh and then uh surgery ligament, reconstruction for high grade and complete tears. And when they do reconstructions now they can use all sorts of different uh components to reconstruct the ACL. They can u use autografts, so tissues from the, the person themselves. So either a hamstring tendon or part of part of the patella tendon or they can use cadaveric allograft from, you know, a deceased patient where they'll use uh hamstring or patella from somebody else. Questions on knee before we move on to the ankle. This is the last last case. All right. So we'll talk about normal anatomy here. You guys, uh you know, being sports medicine, folks, you're gonna see ankle injuries out the wa out the wazoo. So uh just giving you an appreciation of normal anatomy is gonna be really helpful. So, we have three standard views of an ankle. We have an anteroposterior ap view right here where you can see the distal tibia, the tibial metastasis fal scar is closed in this patient who's probably a late teenager or early twenties, the medial malleolus, which is that bony prominence stuff, the medial aspect of the, of the tibia, the uh tibial pla fond OK. The flat articular surface, oh actually curved right there, but articular surface of the distal tibia, the fibula diapsis metap and then the lateralis. And then we also talk about the posterior malleolus all on the poster aspect of the distal tibia. So you have a posterior malleolus, a medial malleolus and a lateral malleolus. And then, so the next question, what in the world was a Malleolus? And it means, you know, if you think mallet, it's like a little hammer. OK. So these are all thought, you know, somebody uh back in the day thought these, you know, were like little hammers banging on this amble right here. So we have the, you have the talar dome right here, which is sort of the ANB so to speak, you'll notice that these bony structures in conjunction with the ligamentous structures that attach these bones form this alcove right here or mortis and tenon configuration, which is like a carpentry term. So the mortis and the tenon which fits into it right there. Uh this oblique view right here, if you pigeon toe, you, if everybody sort of takes your ankle and pigeon toes, it like 10 or uh 15 degrees, that's what you look like on a radiograph and that she gives us a little bit better look at the mortis joint right here. So this is also called a mortis view and then 90 degrees off the AP is your lateral projection right here. So with these three views, you can appreciate the a lot normal alignment of the ankle. OK. You can see that the talar dome right here is centered on the tibial on all three projections but in particular, these two views that are 90 degrees off of each other. Anytime you have 22 views that are 90 degrees off from each other, we call those orthogonal views, OK, 90 degrees off from each other. And when you have two orthogonal views, you can tell where things are in space relative to each other. So we can clearly see that the um you know, the talar dome right here is centered on the tibial bear. It's so nice normal configuration. So we have our talus talar dome, posterior subtalar joint, you have a middle subtalar joint and anterior subtalar joint. You have your calcaneus right here. Calcaneal tuberosity, your achilles tendon inserting onto the calcaneal tuberosity right there. You can see and then you have the bones of your midfoot and forefoot, which we don't see that well. So we have your navicular and cuboid right there. All right. And then you get into pathology. OK. So clearly our ab our alignment is abnormal and there are multiple things wrong in this case. And I'm gonna take our time and go through. This is our last case and there's not a lot of, I don't have any word slides from this one. So I'm just gonna talk through it. So here we can appreciate there are many things that are wrong. The medial melleus is fractured and the distal fragment right here is displaced. OK? The lateral malleolus is fractured. There's an oblique fracture to the distal dia metaphysis or the junction of the diapsis and the metap of the lateral malleolus. There's for shortening of the fracture fragments. There's medial right here, medial uh and anterior apex angulation along the distal fibular fracture site. You can also appreciate that there is on the lateral projection. There's an extra bone fragment right here that has gotten chipped off of the posterior malleolus. So we have a posterior malleolar fracture, a lateral malleolar fracture and a medial malleolar fracture. So this whole injury would be called a tri malleolar fracture, trimalleolar fracture. If you just had the medial and lateral, that would be a bimalleolar fracture if you just had one malleolus, submalleolar, but usually it is called a medial mall or lateral mall posterior mouth fracture. Uh We can also appreciate that the joint of the articulation between the distal tibia and the fibula in this case is too wide, that's wider than a s that's wider than five millimeters. So, there's been injury to the distal tibiofibular ligamentous complex right here. And that's commonly seen in bad ankle injuries like this. Furthermore, the alignment of the ankle is abnormal in one more way and that the talar dome right here should be centered on the distal tibia but is I don't and posteriorly subluxed almost dislocated but not quite. So we have posterolateral subluxation of the talar dome with respect to the tibial paon. So we have displaced trimalleolar fractures with disruption of the distal tibiofibular ligamentous complex or synesis, uh right here and then we have posterior lateral subluxation near dislocation of the ankle mortis. So a big injury, um it looks like it could be close to an open injury. I don't know if I see gas there for sure, but uh obviously this is a bad injury and uh clinically, you know, you see bones stick out, obviously, it's an open injury. So they put Humpty Ty back together again and then they reduced it and put AAA Splint on this patient. And it's easier to appreciate the fracture plans once you get to the alignment back to a more of a normal configuration. So here's our medial mee fracture. Here's our lateral malleolus fracture. They reduced the distal tibia fibular synostosis right here and then they reduced the posterior malleolar fracture. And then you can also appreciate that the talar dome is in a more normal configuration with the tibial font. It's a nice job. Uh sports medicine for Ortho folks with a reduction and the splinting and then they got them over to the or and they put in plates and screws along fibula to stabilize the fracture. These screws are actually, they're where they should be even though they're not associated with a plate. These screws traverse the major fracture plane of the la Moelis and they're called the lag screws and they hold the fracture five minutes in place. So they can put the plates and screws in place here. And then they use a single, partially threaded cannulated cancellous screw. And actually two of them over here on the medium list to hold the medial molar fracture fragments in place. And then in this case, they're letting the posterior maus back here heal by secondary intention, did not put any screws in it. So a good job, everything looks near anatomic of the alignment. Uh You guys did a great job. Thank you very much for taking time to uh listen to some of the discussion of anatomy pathology and how we use imaging to help answer important sports, medical questions. What uh what questions can I answer for you guys? What do you think the mechanism of injury was for this last one to cause all of that? Yeah, great question. Um Man, that's a good one. So I would imagine that there is probably an E version type injury. Uh Actually, this is great. So great question. This is good. So you'll notice that uh on the oblique fracture here, the lateral leiss, you notice it's oblique. OK. Uh It's a little bit hard to appreciate, but you can see there's an oblique fracture plane, whereas over here on the medial side, you'll notice it's transverse. Do you guys appreciate that? Ok. Transverse here, oblique over here that tells us that likely that there's a pull off type injury here and a push off type injury over here. So we're thinking some sort of E version and maybe like an A B duction where the toes get twisted out away from the body. So that, that's my guess on here. Uh There are different uh grading schemes or schemes that talk about the mechanistic injuries of ankles uh based on the findings on a radiograph and a commonly used one if you're, you know, look interested in, you know, chasing that, that rabbit down the hole. Yeah, it's got a funny name, but it's two names. La Hansen au ge dash. Hansen Han se n. Uh There's a, there's some really good articles in the radio radiology literature that show, you know, the mechanism of injury and then talk about the different grades of those and it's based on whether, you know, there's external or internal rotation. A B duction or ad duction, um those kinds of components and forces going on. Yeah, great question. In this case, that's what I would imagine. Probably like an E version with some sort of A B duction component. All right, thank you. Yeah. Hey, listen, thanks for putting this together. It's a pleasure to meet with you guys. Uh Once again, my name is Cooper Dean. Um here at the UF Radiology Department, uh if we can be of assistance with you when you're on rotations, uh normal, you know, me and my colleagues work at the orthopedics and Sports Medicine Institute in the radiology reading room down there on the first floor. Um I'm not there as much as they are since I'm doing program director stuff for our residency program. But you guys are always welcome to either call or come down and talk to us. So please don't be shy and hang in there. Second year is tough. Uh I was a UF medical student myself, so I remember it well, uh it's good times it goes fast, learn a lot, hit the books and it pays off. So uh proud of you guys hit it hard and look forward to working with you guys when you your rotations. Ok? Thank you so much, Doctor Dean. I really appreciate it. You're welcome. You guys take care. Have a great evening. Thank you. Thank you.