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No. Ok, thank you. And those hanging and start now. Ok. Ok, good evening everyone. Uh My name is Gerald. I'm one of the orthopedic registrars based in Mersey. So today I'll be talking about musculoskeletal radiology. Now, this session is mainly focused um towards medical students. Um, but I, if you're a foundation doctor or junior doctor, that's, you know, gonna start orthopedics or is, are just interested in M SK radiology, then that would be um beneficial for you as well. Ok. So, uh let's start, let me just go to the next page. Fine. So the main objectives uh for this talk would be first of all, the having a systematic approach to interpreting M SK radiographs. Um We're gonna go through some basic uh fractures and x rays as well. Uh And last, but not least we'll be focusing on joint disease. Uh I think generally it's quite difficult to cover everything in M SK in a single session. So this will be the main um focus for this session. Um towards the end, I'm gonna try and make it interactive because there'll be uh some cases that I can um discuss with you guys about and feel free to uh volunteer or just type in a chat box if you know what the answers are. All right. OK. So as with any approach to interpreting x-rays, um it's your standard ABC S, all right. So with M SK, you've got a which is alignment, OK. Uh And when we talk about alignment, we usually compare it to the joint above and below. Uh And this is because there is usually a joint uh in between which we will then use that as a reference point for your alignment. B obviously stands for bones. So you'll talk about the density and the quality of these um bones on the x-rays uh C obviously is your cartilage. So the soft tissues in between your joint spaces, is it narrow? Is it uh widened? Uh and last but not least, um you've got the surrounding soft tissues which you can describe further. OK. So again, as I've said about the alignment, um you will normally have to compare the bones uh in question with relation to the surrounding structures. Uh And as I said, it, this is in rel relevance to the joint surfaces of that particular x-ray. And before you describe certain injuries that involves joints, it's usually a dislocation. And it's important to know that before you describe it as a dislocation, there is also uh another term called subluxation. So the main difference between these two is that a dislocation means that there's completely no apposition between um the two bones that form the joint. Uh And if there is only a partial apposition, you can consider this as a subluxation. So I've put some images on so that it's uh more clear uh in terms of what I was trying to say. So if you look at the picture on the left, uh you can see that the humeral head isn't centered completely next to the glenoid. Uh We call this a high riding humeral head, which means that there is a migration of the um humeral head in relation to the glenoid surface. And you can see this is quite a common pathology, usually in chronic rotator cuff injuries. Um or if you've got lax glenohumeral ligaments. Um So it's not really a dislocation per se. It's a subluxation which is due to chronic inflammatory changes to your rotator cuffs, uh or glenohumeral ligaments. Now, the picture on the right uh shows that there is a dislocation because you can see that the humeral head articular surface is completely out of place in relation to the glenoid articular surface as well. Uh So this would represent an anterior dislocation of the shoulder because uh you can see that there is an overlap between the glenoid surface and the humeral head. Um And usually if it's an anterior dislocation, the shoulder would be an external rotation um which I'll describe further in the, the subsequent X rays. So, with bones, um you can comment about the shape and the size of them. So in some cases, you get genetic abnormalities such as in achondroplasia. So then in those cases, the bones do not develop as uh into your standard adult sizes. You can also comment about lucency and opacity that you find on some of these x rays. And that may suggest um sclerotic lesions or even lytic lesions. Um usually in uh cancer, uh bone cancer. Um you can also mention about cortical continuity. So usually when you look at M SK radiographs, you would then trace the edges and the cortices to see if there's any irregularity. And usually in most cases, both the cortex surfaces, they are quite smooth. And if you do find an irregularity in the middle, uh that then suggests that there might be a fracture or a periosteal reaction which can suggest um pathological fractures or growths underneath and last but not least. Uh You can also comment about growth plates if they are present. So if you look at the image uh on the right, uh that is a wrist X ray of what we describe as a skeletally immature um patient because with kids usually uh in boys, they um grow, they have their growth growth plates fused around the age of 11. Uh And with uh girls, it's normally at the age of 13. Uh But this is just an average they do fuse at different stages depending on which um uh bone. It is. So let's go on. So see, we're talking about the cartilage because um you can describe it as decrease uh decreased joint spaces which you normally find in osteoarthritis, increased joint spaces. You can normally see if they've got joint effusions. Um And last, but not least, you can also comment about chondrocalcinosis. Does anyone know what that refers to or what that might suggest in terms of a diagnosis? No one? Ok. Uh So chondrocalcinosis is usually um calcium deposits which you do find in pseudogout. OK. And um it's calcium pyrophosphate crystals that are deposited within the joint in um pseudogout. OK. So if you look at this image here, if you look carefully within the joint spaces itself, you can see that there is some opacity um within the joint surface. If you see there's one over here on the lateral compartment, uh there is also a bit of opacity here on, on this side. Uh So these opacities within the joint is usually indicative of chondrocalcinosis, which is for uh pseudogout. And last but not least I've mentioned about describing on the soft tissue. So, if there is evidence of a joint effusion, um which sometimes you can see in features of lipohemarthrosis on the x rays, um I uh you can sometimes see gas as well. So if you, you do see gas that can suggest that there is an underlying infection, um usually you can see it in neck fas or even patients with uh osteomyelitis or septic arthritis, um which is suggestive that there is underlying bacteria producing that calcification. Usually in patients who have got vascular disease, um there might be masses as well uh for patients with um benign or um malignant growth. And in trauma cases, sometimes you can see patients that have got foreign bodies um on in their soft tissue spaces. So this is what we call the pa fat pad sign. Um And when, when you do see this, it's usually indicative of what's called an occult fracture. So that means on the x rays itself, you can't see that there is any disruption in the court's disease. But if you can see that there is a posterior fat pad, which you would see over here, that is suggestive that there is potentially an underlying fracture that you just can't see um in the bones itself. Seeing an isolated anterior fat pad can mean that it's normal, but you should, you shouldn't almost always never see a posterior fat pad because if you do see one, then that is um indicative of uh an underlying fracture. And this is useful mainly for Children um who you suspect to have a supracondylar fracture of the elbow because these are emergency cases that you would need to um take them to the theater overnight. Um But usually if it's in adults um seeing this posterior fat pad sign, it can also mean that they've gotten a radial head fracture, which is less of an emergency. Uh This is what lipohemarthrosis looks like. So the reason that you've got this difference in fluid levels is that you've got the fat pad that's been elevated by uh blood uh um blood levels underneath. So if they've got a fracture within the joint itself, uh and it, it bleeds out from the joint. So you can see that this opacity here in this layer um with a straight horizontal line which suggests that there is blood collecting underneath within your joint space and that causes the fat um above it to be elevated. And that's why you've got this difference in fluid levels on the X ray. So now we talk about describing fractures on radiographs. Um there is usually a system about it. So if you do get them in your acies or if you have an orthopedic placement and you have to describe x-rays to in, in the trauma meeting. Um You just go through it with a systematic approach. Ok. So first you talk about you, you have to think whether it's what type of um fracture is it in terms of fragments. So if it's a clean break, uh it's a simple fracture, usually resulting in two fragments. If it's more than that, it's comminuted. And then the next bit is knowing if it's an open or closed injury. Usually this is more clinical rather than um what you see on radiographs. Um But those are really obvious in terms of the angulation or the displacement, you can sort of identify that is likely to be an open injury. Um You want to see if the fracture line itself extends into a joint. So that means it's either extraarticular, which means it's confined outside the joint. And if it involves the joint and it's intraarticular, and this is important because this in orthopedics makes it very important for us to decide if it's gonna be operated or usually uh decided for conservative treatment. So again, um there's you, you have to also know the different types of fractures based on the direction and morphology of it. So if you look at this picture over here, uh these are the very common types of fractures that we often see. Uh So here we have the transverse fracture which usually results from a direct uh hit to the bone. Um And with a, with a perpendicular force to the axis of the bone itself, that's how you develop this transverse fracture. Uh open fractures. Again, they are not very obviously seen on x rays unless the deformity is so big that you can sort of um guess that it's gonna be an open fracture, oblique injuries. It's usually from um the f the direction of the force is along the axis of the bone itself. So usually if they fall from a height, um and it's the a parallel force to the uh bone that causes the fracture, that's how you get an oblique type. Uh And then obviously, this is oblique displaced, commuted, it's just broken in multiple pieces. Sometimes you do get segmental fractures um depending on it's usually a combination of an axial force which is parallel to the axis of the bone. Um And in addition to a twisting injury, you also sometimes get avulsion injuries. So if you see a small piece of bone being chipped off uh in an area where there are soft tissue attachments, it's usually an avulsion injury of a ligament or tendon rather than an actual fracture. Um spiral fractures, it's usually um if you, for example, the very common um mechanism of injury is when you've got someone who runs, gets your foot stuck in the ground and then twist it. Uh you didn't get a spiral injury, green stick injuries, they're usually in pediatrics uh because their bones have not skeletally matured. Uh So they are very bendy. Uh So that's why sometimes you get unicortical fractures, uh which is your green stick um types. So after you've considered these factors, there is a specific uh acronym that you can use to describe any type of fracture. And that is what I call star S TA R. So S stands for shortening. So you look at the X ray and you see how much uh overlap there is between uh the two fragments. Um And then if it does. So, first of all, I think it's important to know what a normal X ray of the, of the bone in question that you're looking at is first and then from there, you can identify how much of shortening is um present. And again, in orthopedics, this determines whether we decide for surgical treatment or not. In some cases, T is translation also known as displacement. So you want to see how much is it displaced because in certain fractures, if it's beyond a certain uh cut off again, we would probably operate on those. But if it's within say two millimeters in um uh you know, like a distal radius fracture, then sometimes that's, you know, managed conservatively angulation. It's important to describe how much angulated it is not just medial to lateral but also from an anterior, posterior uh point of view. Um And when you describe angulation, it's always describing the distal fragment uh in relation to the proximal fragment. So if you look at this uh angulation over here, so assuming that this is the um uh femoral head and then this is the knee and then this is angulated outwards towards the lateral side. You would say that this is um angulated in a Varus position. So, Varus and Valgus, if you remember in med school, Varus uh Geno valgum valgus is your knees and Varus is the opposite direction. OK. Uh And then last but not least you have rotation. Uh So that's the orientation of the joint from one end of the fracture bone to the other end. So this is where we say having images x-raying the uh joints above and below is important because you want to see how much of rotation and you can only do that by comparing the position of the fracture in relation to the joints um above and below. So we'll talk about some common fractures. So, tibial fractures, um you have got three main types and this is again where the joints of the cyst are. So, if it's at the proximal tibia, we call it the tibial plateau. Uh And if you've got a fracture in that area, it's, and it's considered an intraarticular fracture at the, at the level of the knee. Uh if it's all the way down to the ankle, um we call this joint surface here the tibial pla. Uh So if there is a fracture that extends into that, then it's an intraarticular type fracture at the ankle. And then obviously, if you've got any fractures in between, uh it's a tibial shelf fracture. So, um distal radius fractures, these type of fractures are very common, especially in the elderly. Um And I'd be very careful in describing uh some of these as colly fracture because they are specific criteria in what you would consider as a collis fracture. So, colli fracture is a combination of um a fracture at the distal radius that has a dorsal angulation, uh dorsal comminution. Uh and also in association with the ulna steroid fracture. So if you don't have all of these three components, you technically can't call it a col fracture. So whenever you see fra uh fractures like this, uh I would just describe it as a distal radius fracture. Um So, does anyone wanna have a go at describing this what you see on these x-rays? Uh You can type it in the chat box as well. I don't, I don't mind. Mm OK. Fine. Um So again, if you use the um analogy that I was describing earlier, if you use star, so you can see that the radial uh the distal end of the radius is shortened. OK. So the radial height is usually the the the radial styloid usually sits high up here. Um But you can see that it's significantly shortened um below the level of the ulnar styloid as well. OK. And on the lateral, you can see that this bit is usually much higher up, but then it's significantly shortened because it's angulated in a dorsal position. Um And then it's also commuted, it's intraarticular. I imagine it's quite difficult for you to appreciate that. But then you can see that there's a midline split over here, which means that there is involvement of the joint. Um It's dorsally angulated because this joint surface, the radiocarpal joint that we describe it as is totally angulated in normal um x-rays, this whole surface is usually angulated vally like that. Uh uh And you, the normal value for that is 11 degrees. So, the fact that this is not even at neutral um sort of flat horizontally uh suggests that there is a significant uh dorsal angulation. Uh It's also combated um uh dorsally and there is an ulnar styloid uh fracture associated with it. So, in this case, yes, you can call it a collies fracture. But um I'd be careful in describing the wrist fractures that you commonly see uh as collies, um distal radius fractures with dorsal angulation, dorsal commu uh associated with an ST fracture would be more than enough. So next, you have scape fractures. Um So the main worry about this is the worry of developing avascular necrosis and it is often a missed injury um because it's not always very clear like this. Sometimes you do get the occult scaphoid fractures that clinically um is suggestive of one. So you palpate your anatomical ST box. Um You do a radio um you do um uh thumb compression test. Uh So where you, you, you take the thumb, you, you um uh radially deviate the wrist and then you just press down onto the thumb. So if you do these two tests, um and if there is tenderness specific in those areas, although you can't see anything on the X ray, what you tend to do is bring them back to clinic in a week's time, get more X rays and see if there's any development of a sclerotic line. If there is, then there is a suspicion that they have got a ski white fracture, then you would then request a CT scan to identify um if there is an actual fracture or not. Because sometimes with X rays, they're not very clear in identifying these occult fractures because they are essentially just two dimensional views. But a CT scan would then be very specific because it's three dimensional. Um and it's a lot uh more accurate in terms of finding these occult fractures. So, scaphoid fractures, if you split them into zones of injuries. So if it's fractured at the waist or if it is fractured at the uh uh proximal pole, uh these fractures would be of much higher concern because they are at risk of avascular necrosis. If you've got a fracture around the distal pole, um you wouldn't be as worried because with scaphoids, they have got a retrograde blood supply that comes from the wrist and it travels up and supplies it at the distal end over here. So imagine if you've got a fracture that is at the waist or at the proximal pole, it doesn't receive that retrograde blood supply, then it often dies and goes into necrosis. Another type of fracture that is prone for avascular necrosis is your femoral neck fractures. And I think this is uh very commonly tested in amongst uh medical school exams, er, or being quizzed on in orthopedic departments. So, with hip fractures. Uh We usually divide them into intracapsular and extracapsular um fractures. In some cases, they are very subtle to see and in those cases, they will be missed. Looking at this X ray over here. Um Sometimes it, I can understand why it might be missed because overall, um I think the teaching that most medical schools ate now is um looking at the sentences line. So the sentence line starts from the superior pubic rami. It goes all the way past the acetable at the inferior aspect. Uh and it joins with the femoral neck all the way down to the lesser tranter and down to the femur. Um In this case, sometimes, uh it might be mistaken as osteoarthritis because they might think uh some people might think that this is um osteophytes. But if you look closely, you can just make out that there is a fracture line over here and this has been impacted. Um The femoral head has been impacted onto the rest of it. Um So you would class this as a subcapital type of neo feur fracture. Um Let me just go on to the next slide. Uh OK. Yeah. So as I was talking about Shen's line, so again, you find where the superior pubic ramus is, trace it all the way to the inferior aspect of the acetabulum down to the femoral neck and then to the rest of the shelf. If there's a disruption in this line, then you would be suspicious that there is a necro feur fracture along uh the femoral neck. But it's also important to know that an intact sentence line does not rule out the presence of a neck of feur fracture. Because again, sometimes you do get those occult ones or if the views that were taken um by the radiographers are not, uh you know, um uh perfect, then you, you can miss those uh neo feur fractures. So the different types of neck of feur fractures is dependent on the capsule. So the capsule attaches onto the intertrochanteric line um of the femur on the anterior aspect posteriorly, it attaches 1.5 centimeters just above that intertrochanteric line and basically any fractures that fall within um that area is classed as intracapsular fractures and anything outside of it is your extracapsular fractures. If it's just beneath the femoral head, just at the start of the neck, you call that a subcapital fracture. If it's in the middle, it's a transcervical and at the base, it's basal cervical. Um And then obviously, if it's between the lesser trop to the uh greater truck, it's an intertrochanteric. And then if it's at the level of the lesser truck, um up to five centimeters beneath that level, that's a subtrochanteric fracture. So, it's important to know these because the each of these type of fractures would deci would determine um a specific operation and treatment for these patients. Uh So, for example, uh basis V fractures, they would be classed more towards the same type of treatment that you would do for an intertrochanteric fracture rather than uh a subcapital or transvaal where you do a half hip replacement for those. So with this, again, it's um some, sometimes you might miss that this is actually a neck of femur fracture because if you look at this, strictly speaking, Shin's line, if you trace it up all the way here to the ace table and the rest of the neck, all the way down to the femur, technically, Shin's line is preserved, but you can clearly just make about that. This is a subcapital neck of femur fracture. So if you compare it to this side, you can see that the contour is generally preserved uh just at the neck to head junction. Uh But on this side, you can see that there is a very s um acute bump um on the head to neck junction. Uh So if this is some, one of those cases that you're not sure, then you would request a CT or an MRI, just to confirm that it is enough, some of the common images that we see um of what a typical kno would look like. So this is what an intracapsular neck or femur fracture would look like because it's broken at the neck. What tends to happen is that the deforming forces on the femur? So you've got the iliopsoas that attaches onto the lesser truck and you've got the hip abductors. So what tends to happen is that this uh will be flexed up because the Iliopsoas will pull it up and then you've got the hip abductors that will try and abduct this out. So, in that whole process, that's how you've got the typical signs of, you know, shortened and externally rotated because the ilio pulls it up. So it's shortened and then the hip abductors will pull it externally. And then that's why you've got it as externally rotated. Uh And then the rest of the neck with the head is uh on uh towards the back um that you would see on this a PX ray. So with um we'll talk about ankles as well. So with ankle fractures, um they, it is important, first of all to know what type of views that you're looking at. So this is what a lateral views uh view looks like. And that's pretty straightforward. But with the two other types, what we call the AP view and mortars view, there is a subtle difference between the two. So an AP view is where the X ray beams shoots uh directly anterior to posteriorly. But with uh the mortar view, what they do in the uh uh with the X rays is that they internally rotate the leg about 15 degrees and then they take the um X rays. And what it does is that if you look at picture a over here, you can see that there is a bit of an overlap between the fibula and the talus. Uh and you can't really see the full joint surface um as compared to be. So with the motors view, because you've externally rotated, uh sorry, internally rotated the leg, you can now see the full joint space, uh which is more or less uniform all across. And what this does is that it allows us to carefully see if there's what we called a tailor shift. So with Taylor sift injuries, uh it's usually an unstable ankle and that will tell us that it needs an operation. Uh So that's why we have these two views uh especially when we're assessing if ac a certain type of ankle fracture is to be unstable or not. So what I mean, what, what I'm trying to say with uh uh a tailor shift is if you look at this picture on the right over here, uh the gap usually should be less than four millimeters. But if you start to see widening of the gap over here, that's more than four millimeters that suggests that there is a tailor shift and that the syndesmosis, which is this section uh over here, um what we call the, the incise um that usually is disrupted, uh the deltoid fibers are broken. And then that's why the, the tibia tends to deviate towards the medial side, creating this um widens um medial clear space. So again, that's this is why II stress that it's very important for you to know what a normal um x-ray looks like before you can start uh commenting on uh fractures because to know if something is shortened or not, you, you need to know the normal dimension. So if you look at this, um what we call the talocrural angle, which is measured with a horizontal line across the tibial talar joint. And then you draw another line between the end of the medial malleolus to the end of the fibula. And then you draw a vertical axis across the midline. This angle should always be between 80 to 82 degrees. If it's any more or less than that, then there is suggestion that either the fracture has caused the fibula to be shortened. Uh And you've not restored the uh ankle joint to what it needs to be. Uh Next, we'll talk about uh we oh OK. Hang on. So I think there's a question. Do you mind explaining why the diagram of the ankle was a lateral view? If you're looking at the medial, wouldn't that be a medial view? OK. Uh Yeah. So let's go back to the X rays. OK. So uh II kind of understand your, your question in terms of why is it all called a medial view? But it's, it's a generic statement across all types of um X rays that we take. It's usually what we call AP and lateral view, lateral, meaning the orientation of it is from the sides. Um uh There, there, there isn't such thing as a as a medial view. Um It's just a generic statement that we uh describe ankle view, uh sorry, uh x-ray views as ap or lateral. Those are the most common types. I think when you're trying to decide between medial and lateral, um it's, it's more of anatomical when you're describing um anatomical structures. If you're describing injuries, then you can talk about medial and lateral aspects. But with um radiographs, it is just a generic statement of lateral or ap if you see a view on the X ray from the site, it's always a lateral view. And then obviously, if it's back to front, it's um ap OK, I hope that answers your question. Uh Sorry. So if you wanted to see a view of so the, the bu t so tibia, would that be lateral or would that be me medial view? Uh So w when you there, there is no medial view, there is only a lateral view and the lateral view just allows you to see what it looks like from um the sides. So when you take, so say if you take the X ray beams um based on what the picture is showing or if you take it from the other end, it will more or less show you the same image that you're seeing here. The only difference is that obviously the talus will be on the left side and the rest of the foot will be on the right side. So that's, that's the only difference if you take the beams from the other direction. But the, the, the, the morphology of it is more or less the same. The only difference is that the sides as in like for in this, in this case, the talus will be on this side and then the foot will be on this side. But what you see across uh of what the bone looks like will be more or less the same is that OK? Yes, thank you. All right. Uh Fine. So we're coming up to Weber fractures. So this is what you a standard way of what you would describe fila fractures in general. So, Weber A B and C and that is all in relation to the level of your syndesmosis. So, again, the syndesmosis is made up of four ligaments that form around the incisor. So where there is an overlap between the tibia and the fibula, that is your ankle incisor. And in that whole section is the syndesmosis, which is a combination of four strong ligaments that keeps the tibia and fibula together at the uh distal end. So Weber a fractures, they are below the syndesmosis and they are the ones that are usually very stable most of the time, if not 99.9% of the time these injuries all are treated conservatively. Um And because they are classed as stable fractures. So if you see these patients with these injuries in the knee, uh they can almost certainly go home um without any form of intervention or just using like a walking boot or comfort shoes. Uh Webber B uh is at the level of the syndesmosis. So with these injuries, you, they can be stable, they can also be unstable. Uh and the way you would assess these ones is that you would palpate and feel the medial side uh clinically. And then obviously, if there is tenderness, then you would, you would suspect that it's an unstable injury and then you bring them back to clinic uh where they will have weight bearing X ray views. So what that means is that when they weight bear, uh they will stress the fracture site. And if the ligaments aren't holding it um in place, then you will start to see its tailor shift, which is what I was describing earlier where there was a widened gap over here. If you do see a tailor shift that always needs an operation. If you get them to weight, bear with the fracture and it's still in its place and it's not moving, then you can treat that as a stable fracture. And then in we Weber C fractures, they always are higher than the uh syndesmosis and they are uh deemed as unstable. So this is what the was the syndesmosis I was describing. So it's made up of four main ligaments, as I was saying. So the front one, you've got A I TFL anterior inferior tibia fibular ligament on the back. Uh on the posterior end, you've got the uh P I TFL, posterior inferior uh tibial fibular ligament. You've got the inferior transverse ligament and in between, you've got the intraosseous ligament and these four ligaments make up the syndesmosis that determines whether you have the tailor shift on x-rays or not. Uh moving on to pediatric uh uh fractures. So you've got uh what we call Salter Harris type fractures. So you can only use this description in patients who have got afi so I appreciate the pictures are not very clear over here. Um But in in kids who have got growth plates, uh usually the epiphysis er and the metaphysis have not fused and that's why you've got like uh what looks like a joint space uh between the epiphysis and the metaphysis. So, if they have got fractures in these type of uh images, you can use what's called a Salter Harris um classification to describe them. So if you have a fracture that goes through horizontally across the ps uh that's type one. OK. So there's an acronym for it. It's called Salta for Salta Harris type one is sway, it goes straight horizontally across the vices A is your type two which is above. So it goes above the piss and this can be quite confusing in some cases because in the in in ankles, it's easier to understand because a above means it goes upwards. But if you've got, you know, like a distal radius fracture, a means going towards the metaphysis. So it's going to be below if that makes sense. So this a above refers to the direction of the metaphysis, whether that's in the ankles, whether that's in the wrists, the shoulders above means you are heading, the fracture is heading towards the metaphysis and not the other way towards the joint. Type three is your l lower. Um So it involves the epiphysis. So I think you just need to remember that above mean means going to the metaphysis lower means going to the epiphysis towards the joint. And then type four, you've got a fracture that goes through both epiphysis and metaphysis. Uh And you've got last but not least type five, which is r uh ram meaning that it's a compression type injury, uh compression or crush type of injury. Ok. So I think we've uh talked mostly about fractures. We'll go on to joint diseases now. So, uh the most common type of joint disease is osteoarthritis. Uh There is an acronym that uh is gonna will be useful for you to describe uh features of osteoarthritis on X rays and it's called loss. Lo SSL stands for loss of joint space. So, if you can see on the medial side here, um So this is the pelvis, this is the femoral head, neck and then the rest of the femur um the medial side, you can see that the joint space is a lot wider compared to the one up here. And that's because this is the weight bearing portion of um the femoral head. So that's why there is a narrowing on, on the um uh joint space in this area as compared to the medial side. So this is loss of joint space and then, oh is your osteophytes? Uh So if you can see at the inferior end over here, um there is a bit of a bony prominence uh compared to this area. Uh So the these are osteophytes. And if you look at this picture over here as well, you can see that there are marginal osteophytes usually at the end. Uh because that's where it articulates with the end of the aacab. Uh And that's where most of the friction happens and that's where why it generates uh bony growth in these areas. Um The two ss they stand for subchondral cysts, which you can see sort of pockets in the acitab here on this picture and here on this X ray as well. Uh And then you also get the subchondral sclerosis um uh at the joints uh just underneath the, the joint surface. So you can see the edges of the uh femoral head. They're a lot more sclerotic and the rims of the acetable surface as well. So the these four components make up the key features of osteoarthritis if you need to describe them on x rays. So, if, uh, the, the other type of, um, arthritis would be rheumatoid arthritis that you commonly get tested in, uh med school. Uh, so rheumatoid arthritis, uh, it's a chronic inflammatory disorder that is, um due to autoimmune conditions and similar to osteoarthritis. You have got acronyms, um, to describe them as well, which is le les S less. So similar to osteoarthritis, you get lots of joint space that you can see over here in the radiocarpal joint. Uh and also in between the uh phalanges, there is very, very little joint space and they're almost bone on bone contact. Um You get erosions, periarticular erosions. Uh So you can see that the, the whole morphology of the um carpal bones that they, they have, they, they're not, they're basically not normal. They, they have got eroded areas all along uh the each of the uh carpal bones. And then the two ss in this case, stands for swelling, uh which you would find clinically and you can see soft tissue swelling along the wrist here as well. Uh And then the other s uh would stand for uh soft, uh which is perio periarticular osteopenia. So, in rheumatoid arthritis, it tends to co uh commonly affect the proximal ends of the hands. So you would see that you've got erosions in the metacarpophalangeal joints. Uh So if you can see uh the changes over here, so you've got subluxation of the joints. They tend to deviate ulnarly in late stages. Um And you've got periarticular osteopenia. So if you see the density in the ends towards the joints, they are a lot less dense compared to the uh the shafts of the uh phalanges. Um And then in late stages, uh in rheumatoid arthritis, they become more clinical in terms of features. So, early stages, you would only pick them up in radiographic changes uh as you can see here. But in late stages, it becomes more of a clinical deformity. So that's where they get the uh deviation of the uh uh MCP joints. LY. Uh And this is usually because of ligamentous laxity due to the uh chronic inflammatory changes from the autoimmune um condition. You've also got psoriatic arthritis. So, um these are very um uh obvious from the, what we call the pencil and cup deformity. So what tends to happen is that uh unlike rheumatoid arthritis where it affects the proximal ends of your hands, psoriatic arthritis affects more of the distal ends. So the D IP the distal interphalangeal joints tend to be most commonly affected and the terminal ends of the phalanges, they will undergo Boni resorption. And when you get bony resorption at these ends, uh it telescopes into the er distal challenge. Um and that's what we call the penciling cup deformity. Uh So if you see these changes where you've got a very narrow end, uh articulating with the adjacent phalanx that's called a penciling cup deformity, which is indicative of psoriatic arthritis, septic arthritis. Um that is usually in a few stages. So that would, if you can see the image over here, you can see that the art t the um the cartilage is destroyed, the uh bony cortex is all eroded and you can see that it's spreading up um into the rest of the shaft as well. You also see periosteal changes around um surrounding the bone. Uh And in some cases, you get to see gas, gas pockets uh along along the area, which means that there is underlying bacteria producing um these er er pockets of gas, as I said, it's a progression um with septic arthritis. So, in very early stages, you can't really tell um if it's septic or not because the only thing that you can see is loss of joint space, which you would also have in osteoarthritis. So, in the very early stages, you can't really confirm it if someone's got the septic arthritis just based on x rays. If you wait a little longer, uh the, it will start to affect the underlying cartilage. So then you get erosions of the subchondral space uh and sclerosis, um once it starts to undergo um fibrotic and inflammatory changes, and then if you leave it for say a couple of months, uh that's when it starts to erode into bone. And that's why you develop osteonecrosis uh and subsequently uh flattening and collapse of the femoral head because um it's weakened bone from the uh necrotic process. So this is uh uh an image of uh it's it's an ap pelvis. Um So you can see that this is very late stages of osteoarthritis. You've got flattening of the femoral head and then you've got significant sclerosis around the subchondral space. Uh A lot of subchondral cysts as well in this area. Uh This is, yeah. So this is what I was describing earlier. The psoriatic arthritis, I do apologize. All of these images are supposed to be interactive, but uh I don't think uh I'm getting a very good response. I'll just quickly go through them uh for everyone's benefit. So this is, yes, you can see that there is the pencil and cup deformity um in this. So this is psoriatic arthritis. This is obviously septic arthritis because you can see that there is increased density in this area which suggests uh there, there is soft tissue inflammatory changes, it's eroded into the um ends um of the joint on both sides. Uh This is what we call a subcapital neo feur fracture. Uh Again with Shen's line. Yes, there is a bit of a disruption here, but it's very subtle. Uh So it's often confused as osteoarthritis because uh sometimes uh it can be mistaken that this is an osteophyte this is an osteophyte. Shen's line is preserved and therefore, it's osteoarthritis. But if you look carefully, you can see that there is a sclerotic line growing across, we would suggest that there is overlap because there, there is a fracture. Um in the femoral neck, this is a weber B fracture. Um that because it's at the level of the synostosis. And if you remember what I was saying earlier with these injuries, sometimes they are stable, sometimes they are not. And in this case, uh we would uh consider that this is an unstable fracture because you can see that there is widening of the media space, which suggests that there is a talar shift. And when you have a talar shift, that suggests that the syndesmosis is disrupted, the tel talk fibers are broken and therefore it needs to be fixed. Otherwise, the deformity continues to uh deviate media. So this is a lateral view of a foot. Uh So you can see that there, there is 1/5 basal fifth metatarsal fracture. So this is your first metatarsal here and then just underneath that, this is the second metatarsal, 3rd, 4th and this your fifth. Uh the worry with these type of fractures is that there is uh a classification where you divide the me um basal f metatarsal into a couple of zones. This zone is the watershed area which means that there is a very um minimal blood supply to that specific area. So if these injuries are not operated on in some cases, if they are displaced, uh they will go into nonunion um and it heal um even if it's a couple of months down the line. Uh So this is your distal radius fractures. Uh So with this type of fractures, they are commuted. Uh the radial height is more or less preserved, it is slightly shortened. Uh It is translated minimally probably about three millimeters dorsally. Uh And yeah, it's, it's comminuted with uh intraarticular involvement that you can see over here. So, interestingly, with these injuries, this is in a young patient, you'd probably fix it. But if it's in an elderly, say a 90 year old lady with low functional demand, you would accept this type of alignment because the joint surface is more or less neutral. It's not significantly closely um angulated. Um There is intraarticular involvement but the only worry about not fixing do is that it speeds up your onset of arthritis. So if this isn't in an elderly patient, 80 plus with low functional demand, you're not so worried about that. The main thing that you've got here is that it's um the length is preserved, the angulation is very minimal, probably about 10 degrees uh to its normal um uh position uh and it's not significantly rotated. Uh This is a uh scaphoid fracture through the waist and just remember what I said earlier that these injuries would um warrant uh further investigation a CT scan, uh and possibly surgical fixation as well because of the lack of blood supply, uh causing it to have increased risk of avascular necrosis. Uh This is a, an intraarticular fracture of your middle phalanx of the index finger. Um So you can see that it's quite displaced from where its original position is. And in again, in this case, you would, we would probably want to fix it because um it, otherwise the D IP does not uh articulate well. And you would get prolonged stiffness in this area and typically hand injuries, they tend to be less forgiving. Um And if you don't rehab or if you don't fix it within a week or two, they develop stiffness very, very quick. And um the only way to treat that if you missed it, say three weeks down the line, 34 weeks down the line. Um The only option would be to fuse the joint. Uh So this is an anterior dislocation. Um So you can see that the whole um uh humeral head joint surface is not articulating with the glenoid. Uh So therefore, it's, it's, it's a dislocation, not a subluxation. Uh This is a femoral sharp spiral fracture and that you can see in a skeletally immature child because you can see that there is growth plates in the, this femur uh proximal tibia and at the femoral head as well. Ok. This is a tibial plateau fracture. So you would describe this as an intraarticular fractures that you can see extending all the way down here, it is broken in more than two parts. So therefore, it's commuted. Uh and there is uh shortening as well because uh the joint surface here needs to be more or less at the same level with this. If anything in um tibial plateaus, the lateral uh joint surface is typically about a mill higher than a medial side. So this is very, significantly shortened and crushed. Um compared to its original position. Uh these are images of the knees with which you can see that there is chondrocalcinosis in between the joints. Um You would also can describe this to be uh someone who has got medial compartment, osteoarthritis. So you can see that there is um um narrowing of the joint space on the medial end. Uh and features of subchondral sclerosis in the joint in in the joint surface below and above. Uh So this patient has got medial medial compartment, um osteoarthritis of the knee in addition to chondrocalcinosis in the joint. Uh This is what I was describing about the fat pads. So anterior fat pads, they usually are um present in some cases, but you should almost always never see uh a posterior fat pad if you do see that there is suspicion that there is an occult fracture. So in kids, you can either have uh supracondylar fractures of the elbow. Uh Whereas in adults, it's more or less radial head fractures as I said before. And if you look very, very, very closely, you can just make about a radial head fracture over here because if you trace the cortical lines, it's smooth all the way and then you suddenly get a uh tiny bulge over here. Uh And then you can just about trace the fracture line all the way to the radial head. Ok. I think there is. So someone's asked, Hannah was asking previous image was subcapital fracture. Uh Let me just see. Oh Yeah. Uh um Sorry, I'm just trying to find that image. Mm Yeah. So this, this, this would be a subcapital fracture because it is uh just underneath the head to the neck junction where the flare starts uh here. So fractures that go along this line, they are subcapital and then if it's in the midsection, it's trans VR and then obviously, if it's at the base, it's ba vital. Uh I hope that answers your question. OK. Uh Where was I? So, yeah. So, so this, this is the um uh yeah, the radial head fracture with the uh presence of a posterior fat pad. Uh So this patient has also got arthritis at the elbow. So if you look at the um edges, you can see the osteophyte changes uh over here. Um And just about on this medial side at, at the end uh that's, that's osteophyte changes. OK. Um This is what lipohemarthrosis looks like. So if you can see a very clear horizontal line distinguishing between uh an opacity, uh fluid level. And, and um uh uh yeah, if you can see that there is a distinct separation um between two very obvious uh densities that's like for hemarthrosis because all of this is basically blood and this is fat. Um I think, uh I think I might just keep questions at the end if that's OK. Um And then I'll uh go through the chat box in a sec. OK. So yeah, lipohemarthrosis. And then this is I II put this up because II thought it would be interesting to, to share because this isn't actually a fracture, but it's a radiographic finding that you would su uh suspect that they have got a soft tissue injury. So if you look at the position of the pil in relation to where it usually sits. So again, this is why I say you need to know what a normal X ray looks like in order for you to find abnormal findings. So usually the patella sits a little bit lower than where it is at the moment. So it tends to sit at the uh intercon intercondylar notch which starts around here. So in this case, the patella has gone uh a lot more approximately. Um And then if you look closely, you can see that there is a bit of uh opacity over here in this section and this what connects the patella on the inferior end to the uh tibial tuberosity is the patella tendon. So, because you can see that there is a um proximal migration of the patella in relation to where it needs to be. That suggests that there is a patella tendon rupture because there's nothing holding it from the distal end to the tibial tuberosity. And then you can see that there is some um opacity over here which suggests that there is inflammation around the uh patella tendon. Uh So this would be suspicious for a patellar tendon rupture. Uh This is just um for the juniors in the audience. Um So, in case you're wondering, this is not abnormal, this is uh sesamoid bones. So they are bones at the end of your um they, they are in your first MTP. So they are basically the cushions of your um plantar surface just where your first MTP sits. So, in case uh you're wondering a sesamoid bone is basically a joint, uh a bone that's within a tendon. So, the largest sesamoid bone in the body is actually the patella. So this is all uncovered by the extensor mechanism, which is your patella tendon and your quadriceps tendon and together they form a sheath all around the patella uh going as one a one hole unit across. OK. So, technically, the patella is a sesamoid bone and it's the largest in the body. So this is a shoulder x-ray um of uh again, a skeletally immature um patient because they've still got the um growth plate over here. And what's abnormal about this X ray is that this is a dislocation. And the reason that you can tell from that is because you've, this is what we call the light bulb sign. Ok. So again, this doesn't look normal because it's uniform all across a normal shoulder. Uh A normal humeral head in an AP view should not look like that because you should technically see the GT, the greater tuberosity on this end. And you would want to see uh more convexity um where the humeral head articulates with the glenoid. So for posterior dislocation to happen, the arm goes into internal rotation. So the greater tuberosity that lies over here, it tends to uh bring itself forward. So you can see the GT is about here, but because it's turned, uh it's internally rotated, this um projection of the greater tuberosity then rotates forward. Uh and it looks uh like that from this view. So that that's a dislocation. So just yeah, just to show you what it, what it um what I meant by that. So you can see that um a normal um glenohumeral joint, there is more convexity where it articulates with the glenoid. Um And then you can just make about the greater bras as a prominence on the lateral end. So that's what a normal uh shoulder should look like. But if it's all uniform, all across. That means this has internally rotated and dislocated posteriorly for you to see this image. Um This is I appreciate it might be quite hard to orientate yourselves. It's uh an inferior dislocation of the shoulder. Um The reason why it looks a bit weird compared to this image is because of the projection. So this is an AP projection. Uh This is in a projection that they're trying to achieve an AP but in trauma cases, sometimes um because the pa patients uh severely abducted at the shoulder, they can't always get an AP view because the patient is in huge amount of pain, they can't um position themselves and stand in front of the X ray board to get an X ray uh a PX ray. Um So if you just look at the anatomy, this is the clavicle, this is the scapula which then branches forward and forms the achromia and you have the achromic clavicular joint. This is part of the um scapular that projects to the front. It's the coracoid process. Uh So the humeral head needs to lie somewhere up here, but it's dislocated inferiorly. And if you look, this is the glenoid surface, so the humeral head needs to sit slightly more um higher up where the glenoid surface is. Uh So, yeah, that's what I was um describing. So, in terms of incidents, you commonly get anterior dislocations, they are the most common 96%. Um and then posterior inferior and superior are a lot less common um that you would find clinically in hospitals. And that is it. Uh Let me just see if there's any, any questions at all or? OK. So I think I got around to Hannah's question, Rhoda. How can you tell spiral uh from oblique? So an oblique is basically a clean break. So let me just bring up the images again. Uh Yeah. So, so yeah, and oblique is basically um a clean break. Uh you know, in a, in a, in a single plane. Um but a spiral fracture is that you'll find fractures in two different planes even though they're in the same bone if that makes sense. So an oblique in a single plane, if you look at it from an AP view or lateral view, it would still be in the same area um in oblique way. Whereas a spiral, it's, it, it, it, it goes, it goes all the way around like a, like a spiral, a case if that makes sense. So the official term to describe the difference between both of them is that an oblique fracture is a fracture that occurs in a single plane. Whereas a spiral fracture, it's in the same bone, but it happens in two different planes. That's why the position is uh looks at different levels um on, on, on an X ray. Uh let's see. Well, is it um So yeah, the difference between subluxation and dislocation is that the the simple difference with a uh uh the subluxation and dislocation is that subluxation is a partial apposition. So you still have uh contact between the articular surfaces, whereas a dislocation it is completely offended. So in this case, you can see that part of the humeral head, articular surface is still in contact with the glenoid articular surface. So this is a subluxation, whereas in this case, the whole humeral head has gone forward and it is not articulating with the glenoid anymore. Um So that is a dislocation. OK. Um Hannah asked again when you talk about dorsal and ventral displacement, does that always refer to the distal fragment? Yes. So when you describe displacement um or even a dislocation, it is always in reference, you're describing the position of the distal fragment in relation to the proximal fragment. So again, with the colleagues, uh let me just bring up the x-ray again. Very. Yeah. So you describe the distal fragment. So the distal fragment is dorsal do uh dorsally angulated. And that is because it's you're describing it in relation to the proximal bit. So the proximal bit is this, this is the original position. And then if it's facing dorsally, then it is dorsally angulated because it is dorsally angulated in relation to the proximal end. Similarly, if this joint surface is facing here, then that is a ventral um uh angulation because that is the position in relation to the original um proximal fragment OK. Is it possible to have a spinal segmental fracture? Um You, you, yeah, I've not really seen those before because they both happen from different types of mechanism. So a spiral fracture is usually um from a twisting type injury. Um uh but a segmental is a combination of an axial and a twisting type of injury. So I think to already have a segmental fracture. It's quite difficult for you to have a different an additional type of fracture in the same area. Um At the same time. Cool. Um Is there any more questions or? Yeah, I think that was all the questions. Thank you very much. Um Doctor Tan for delivering this session. If yeah, if anyone has any more questions, feel free to put it on the chat and I've also posted the um.