It's a pleasure to return this year. I've learned quite a bit from Tom Gill over the last 10 years or 15 years. I just want to say that practically none of it has anything to do with medicine, however. All right, I'll be covering issues related to the elbow, wrist, and the hand. And in the elbow, I'll be focusing on very specific topics on our collateral ligament and dislocation, simple dislocation. And in the wrist, triangular fibrocartilage, some ligament injuries. And if I have time, the first MCP joint in the hand or thumb. In throwing athletes, the owner collateral ligament can become abnormal for one of two major reasons. One, repetitive and cumulative stress that can result in abnormal morphology of the ligament, as I'll demonstrate. And eventually, that can lead to other imaging-related findings, degenerative changes that involve the radiocapitellar joint or the olecranon, spurs, loose bodies, all of which are typically better seen by CT than MRI. And then in the acute setting of acute injury, where there is excessive valgus load, owner collateral ligament disruption with adjacent hemorrhage, best seen by MRI, with or without an associated strain injury. So the owner collateral ligament is going to be best demonstrated on a coronal image. This happens to be an orthographic image. And it demonstrates this continuity of the ligament. Usually, you don't see it on one slice. You have to look at three or four slices. But this is showing continuity of the ligament from the medial epicondyle down to the sublime tubercle. And it's very thin, and there can be striations. The axial images do a great job showing continuity of the ligament here at the level of the sublime tubercle. And then coming up from there, the owner collateral ligament, this linear structure that can be followed all the way to the medial epicondyle. And if you can identify it on these sequential images, then it's normal. Also, what we're seeing here is the common flexor tendon followed up to the medial epicondyle. And then notice as well the posterior bundle, its intimate relationship to the owner nerve as it's forming the floor of the cubital tunnel. So all these structures are very intimately related. So here is a throwing athlete over a decade or more. And this is an abnormal UCL in that it is thickened and somewhat lax, but continuous from the medial epicondyle down to the sublime tubercle. This is another so-called adaptive change where the UCL can be followed down to the sublime tubercle where there's this little thin bit of fluid that's undercutting it, the so-called T sign indicating a partial tear, which presumably predisposes this ligament to acute injury down the road. Here's an example of an acute UCL rupture. And we have a coronal T1 and then a STIR sequence. So the T1 is going to be excellent for showing bony proliferation, spurs, fractures. But it's really this fluid-sensitive sequence that you must rely on to identify the sentinel sign of edema or hemorrhage, which then is going to point you to a potential ligament injury or tendon abnormality. So here is this high signal edema or hemorrhage in the expected location of the owner collateral ligament. Here is what's left of the UCL. The stripping here, this T sign, may be chronic, but the acute injury is this discontinuity. Here's an individual, a younger pitcher, who hurt a snap. And this is a comparison of the right and left elbows. And clearly, the asymmetry is related to this ossific fragment, this fracture fragment, at the sublime tubercle. And as obvious as that is on the radiograph, it's much more difficult. Cortically-based fracture fragments, no matter where they are, are much more difficult to identify by MRI compared to CT or even radiographs. So what we're seeing on the MR, and this is an orthographic study, is a normal UCL that can be followed down to the sublime tubercle, where there is this linear defect indicating the fracture line and incomplete healing, given its high signal. So avulsion fracture at attachment site of the UCL. So is this a fracture fragment, or is it something else? Well, it's really not close enough to either the medial epicondyle or sublime tubercle to be expected to be a fracture fragment. It's heterotopic ossification related to a remote injury to the ulnar collateral ligament. And this person has a superimposed acute injury. So here is the ossific fragment on MRI. I say ossific because notice it has bone marrow inside of it that has the same appearance as bone marrow inside this distal humerus. Here is the UCL that's followed distally down towards the sublime tubercle on this orthographic study. So here is some discontinuity of that ligament. And then notice all this leak of contrast material. This is the gadolinium that was injected. And it's injected from the lateral side, not the medial side. So this is not an injection-related phenomenon, which you should be familiar with. Instead, this is capsular discontinuity with extra capsular leak of injected contrast material due to this focal tear. So an acute injury superimposed on a remote injury as evidenced by that heterotopic ossification. So let me address elbow dislocation now. Much less common than shoulder dislocation, but number one in children, number two in adults. Almost always, posterior dislocation is shown here. And it is said that up to 50% of these injuries are related to sports. So I'm going to be addressing the simple dislocation, which involves the absence of a fracture. And in this 46-year-old, I'm not sure this is an athletic-related injury, but she was running. And I'm going to be showing post-reduction X-ray and CT, and then a pre-reduction MRI. So the radiographs, normal alignment. There's a joint effusion, otherwise normal. And then here on the CT post-reduction, normal radial capitellar alignment, no radial head fracture. And as we come more towards the medial aspect, normal contour of the coronoid process, no fracture in that location either. So the X-ray and CT are essentially normal. So this MRI was obtained prior to reduction. So the radial head is clearly dislocated posteriorly. This is the only bone marrow abnormality, not visible on the T1. And it's this faint bone marrow edema that reflects this impaction injury by the radial head against the capitellum dorsal. So a bone marrow contusion, better seen on the fat-suppressed, fluid-sensitive sequence. So a tremendous amount of surrounding periarticular edema and hemorrhage, capsular distension, intraarticular hemorrhage, normal coronoid process. And in these posterior dislocations, the triceps and the biceps are essentially always normal. But brachialis commonly will develop a very large injury to the muscle mass, not to the tendon at its ulnar attachment site. OK, let's look at other imaging planes. This is the patient's flex, so it's coronal to the humerus. This is what's left of the ulnar collateral ligament. This is the discontinuity. As I come more distal, we're starting to see the radial head here, the lateral ulnar collateral ligament, and the discontinuity here due to the rupture of that structure. This is where the common flexor and extensor tendon should be located. And both are essentially non-visualized. So high-grade soft tissue injuries not visualized in the CT or the MRI. This is the median nerve and then the brachial artery surrounded by hemorrhage and hematoma in this where you should be seeing this brachialis muscle, which is severely torn. And then here, ulnar artery as well, essentially in the breeze. Now, so those drastic kinds of findings are in contrast to this individual who had an injury during a jujitsu tournament and wasn't really sure what happened, and the radiographs were normal. But because of disability, came to MRI. So this is a coronal gradient echo image. Gradient echo is excellent for showing small fracture fragments and also for showing ligament injuries. So here on the medial side of the elbow is this ulnar collateral ligament, which is stripped away from the sublime tubercle. So ligament injury on the medial side. Pay attention to the lateral side. And then here is the lateral ulnar collateral ligament coming up towards the annular ligament. And what is most remarkable about this structure? Well, it's lax. It's displaced from bone, where it should be very closely applied. And there is discontinuity. So rupture of medial and lateral ulnar collateral ligaments in combination with non-visualization here of the common extensor tendon. So although this individual had no elbow deformity at the time of injury, the presumption is that, based on these imaging findings, there was a high-grade subluxation or even dislocation with immediate reduction, given the medial, lateral, and tendon injury. And then signs of radiocapitellar instability, given this offset on the sagittal images. OK, I'm going to turn now to the wrist and focus on the TFC initially. And as stated, degenerative and traumatic-related injuries can be identified mostly on MR, with or without an orthographic injection. So central tear is more degenerative. Peripheral tear is more traumatic. And first, let's look at some normal structures. So these are gradient echo images. And the gradient echo, I think, are absolutely excellent for showing this normal scapholunate ligament, this triangular, low-signal structure attaching the cartilage surfaces of scaphoid and lunate. And then here is the TFCC. This is not a tear. That is the junction of the low-signal TFC with the articular cartilage of the distal radius. And then there is the peripheral tissue. And you should expect to see the peripheral tissue, both the proximal as well as the distal components, followable to the uvea, as well as to the ulnar styloid process. And this is the most important region to be looking at, at that peripheral tissue for trauma-related injuries. This is a technologist who had no pain, but we were checking our protocol and she had a central degenerative tear that was asymptomatic. So centrally located, asymptomatic. As a college hockey player, it meets the description perfectly as described in the previous lecture, where there's an ulnar-sided pain. There's this very large defect centrally involving the triangular fibrocartilage. But the peripheral tissue is also abnormal. So there is what appears to be discontinuity or near-dusk discontinuity between the TFC, the disc, and this peripheral tissue. In combination with all this high signal extending out towards the ulnar styloid process. And this is an individual who had a stable distal radial ulnar joint. And then you'll notice that there is this low signal structure hanging down into the distal radial ulnar joint. And this is the donor site for this partially-detached displaced TFC fragment. And this individual went on to an arthroscopic debridement. In contrast to this individual playing basketball, the TFC looks normal, attachment to the radius intact. But then here's the peripheral tissue with high signal edema or hemorrhage separating it from its expected attachment sites here to the ulna, and then to the ulnar styloid process as well. So this person was considered to have a distal radial ulnar joint instability and underwent an arthroscopic repair. So another fall in an outstretched hand. Here is a central TFC tear in somebody who's 57 years old. This is probably a chronic finding unrelated to the current injury. But what else is going on in this case? Here's the gradient echo, which you cannot depend on for assessing bone marrow abnormalities. Here is the T2-weighted fat-suppressed image that shows signal abnormality involving the midscaphoid. Anything linear here? Hard to say. So it could be a contusion, could be a fracture. Here is a widening of the scapholunate interosseous interval with non-visualization of the scapholunate ligament. So high-grade tear or rupture of this ligament in combination with a scaphoid abnormality, which on the T1-weighted images is clearly linear and consistent with a non-displaced fracture. So T1-weighted images, excellent for showing linear abnormalities that are consistent with fracture. The T2-weighted fat-suppressed sequences are more of a gropogram sequence that show marrow abnormalities more consistent with edema and contusion. Same individual. Here is that fracture line involving the scaphoid. 37 years old, remote injury. The scapholunate interosseous interval, maybe it's widened, sort of nonspecific. What about the scapholunate angle? So here on radiographs, it's measured at around 90 degrees, clearly greater than the expected normal range. So suggesting some dorsal angulation of the lunate. Here is the MR image in that same individual. Now this is T1-weighted, and what do you see? You can't see the ligament because it's the same signal intensity as fluid. However, you can see that there's widening of the scapholunate interosseous interval. You have to turn to a gradient echo or a fat-suppressed T2 weighted sequence to further characterize the ligament in this location. So here's the widening, the space filled with fluid. Here is the scapholunate ligament that's interposed between the lunate and the scaphoid with discontinuity here. So clearly, a rupture of the scapholunate ligament. And here are the sagittal images in the same individual. Orientation of the scaphoid, orientation of the lunate. And you can use the same measurement principles as in the radiographs to come up with an angle that approximates 90 degrees greater than expected. Stress-related views, radiographs can be valuable in comparing the scapholunate interosseous interval. Widened here on the symptomatic side compared to the asymptomatic side, and this person went on to a stabilization procedure. OK, in the last two minutes I have, let me address the thumb and the MCP joint. So the owner collateral ligament then is comprised of really two ligaments, one the accessory and one the proper. And its common depiction on the internet is not reflective of reality necessarily because this ligament is not truly in the coronal plane. This is the aponeurosis as depicted in the diagram. In fact, the proper and accessory ligaments are not oriented in the coronal plane. And therefore, in the MR images, do not expect to see the ligament on a single coronal image. You need to look at it on sequential coronal images to determine whether it is abnormal or, in fact, intact. OK, here are some gradient echo coronal images. And I first want to point out this structure here. And that is one of the tendinous attachments of the adductor pollicis. And it's to the base of the proximal phalanx. And you see it in 100% of these MR studies. And I think it's an excellent landmark for identifying the attachment site of the owner collateral ligament proper. And now we're going to go from volar to dorsal and follow this owner collateral ligament dorsally to its attachment site to the metacarpal head. Now, if you were only looking at this particular image, you would conclude that there is a tear of the owner collateral ligament. But if we come back and look at these slices, it's clearly attached and normal at the base of the proximal phalanx. So you have to use these sequential images to really evaluate the continuity of the owner collateral ligament. I'll just show two examples of acute injury, so-called skier's thumb, where there can be partial tear or rupture with or without a stint or lesion. So here's a football player, repeated injuries, new acute injury. And T1-weighted, T2-weighted images. This is that adductor pollicis tendon attaching to the base of the proximal phalanx. And there is no owner collateral ligament in that location. Still, we're not seeing the UCL. Instead, this linear structure that we continue to see more dorsally. And then here is this oriented 90 degrees to the metacarpal head, the so-called center lesion, the UCL underlying the aponeurosis. Sagittal images, normal alignment. And typically, you'll see this blob of abnormal soft tissue. This is a sagittal slice through here. And it's the UCL sticking out under the aponeurosis. And then here in my final case, repeated injuries to the thumb, medial-sided pain. Here is the medial and lateral sesamoid. And the adductor pollicis tendon coming up. Here is the base of the proximal phalanx. And then here is the UCL. And so there is a rupture, given this fluid separating it from the base of the phalanx. And then here is the aponeurosis. And so in contrast to the previous case where the ligament was under the aponeurosis, was proximal to the aponeurosis. Here it's underlying it. And this is not a stent or lesion. It's a high-grade tear or rupture. Thank you very much. Thank you.

injuries

conditions

elbow

wrist

hand