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This 15-year-old has 3 months of ulnar

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sided wrist pain after a twisting injury.

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The most common indication in young people for MRI is

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often ulnar-sided wrist pain, and you are frequently

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looking for tears or injuries of the extensor carpi ulnaris,

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or triangular fibrocartilage, or its complex.

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If you don't know what you're looking for,

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odds are you're not going to find it.

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These first two coronal images, one

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water-weighted, one fat-weighted, start

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out on the dorsal portion of the wrist.

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Showing an ulnar styloid, there's the styloid,

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that is itself swollen and all the tissues around it,

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look how grey, ill-defined, and fuzzy they are.

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They are swollen.

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Now the reason we see the ulnar styloid

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so quickly is that the wrist is pronated,

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so the styloid is rotated dorsally.

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Which means if you want to see the attachments

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to the styloid, like this one right here,

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see a little gap between it and the styloid,

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you probably want to look at both the

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coronal but also the sagittal, which will do.

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So, the styloidal attachments and these peripheral

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attachment areas are at least swollen, fuzzy,

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injured, clinically sprained, and micro-torn or torn.

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But now, let's scroll towards

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the palmar aspect of the wrist.

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Now, we're still dorsal, but as we get a little

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more palmar, we start to see this space right

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here, which is the capsule, and some squiggly,

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wiggly attachments, like this one right here.

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And this one that's a little bit squiggly

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and wiggly, like that one right here,

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and swelling around it or in between it.

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And then there's also this kind of serrated

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appearance in the peripheral aspect of the TFC.

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So what I would like to do now is draw an axial

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projection of the triangular fibrocartilage as if

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you're looking straight down arthroscopically from

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top to bottom or from distal to proximal at the TFC.

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Now in this projection, what we would

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call the axial projection, it is triangular. It’s got

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some attachments to the radius.

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Now let's look at the package that the

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TFC is enclosed in, or invested in.

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Anteriorly, if we were looking axially,

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we would see the palmar radial ulnar ligament.

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Posteriorly, we would see the

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dorsal radial ulnar ligament.

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Now we know from prior discussions that there

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are attachments from the cartilage to these

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ligaments, both anteriorly and posteriorly, and these are called the

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anterior or palmar or dorsal ulnocarpal ligaments.

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And they can then be divided up from

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medial to lateral into different sub

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portions of the ulnocarpal ligaments.

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So we'll pretend we draw those in, and those are

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actually not going anterior to posterior,

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they're going proximal to distal, but you'll see what

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I mean, and they're going anterior to posterior.

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Um, and you'll see what I mean in

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the sagittal projection in a moment.

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So we've got this investing package of the

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palmar and dorsal radial ulnar ligaments.

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So we'll say, palmar radial ulnar

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ligament, dorsal radial ulnar ligament.

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And then they start to converge out

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here, and we'll draw the ulnar styloid.

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So here's the ulnar styloid,

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and here's the ulnar fovea.

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And we're gonna have attachments to the styloid.

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74 00:03:35,680 --> 00:03:36,880 These are peripheral attachments.

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And we'll also have attachments to the fovea.

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Now the attachments to the fovea come off some much

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thinner structures, thinner ligamentous structures,

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and they are kind of mixed in with some vascularity.

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I'd like to make the vascularity red,

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but I've already used red, so I'll use yellow.

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So here's some yellow, and this, this

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complex is known as the ligamentum cruentum.

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And since it's very vascular,

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when it's injured, it kind of swells up and

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produces kind of a mushy type appearance.

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And you are seeing that right here.

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Here's our mushy type appearance.

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I'm going to color over it in yellow.

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There's some more mush right there.

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That's all part of the swollen ligamentum cruentum

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and the swollen, strained, partially injured

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or torn, slightly crimped or micro retracted

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peripheral TFC styloidal attachments, too.

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Remember the ones I showed you

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that were a little squiggly wiggly?

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Those were some of the peripheral attachments.

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So this kind of smudgy thing that I've

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colored over is part of the D package.

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The ligamentum cruentum.

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Then I also mentioned that there was a little

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serrated area in the peripheral aspect of the TFC.

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And I think I'll make that green.

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It's right there on my diagram.

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It's right there on my MRI.

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And even a second one right there.

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That's all part of the peripheral

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injury story.

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So one of the reasons for me showing this to

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you is the grading system according to Palmer

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for traumatic injuries to the TFC,

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Roman numeral one classification system.

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Most common would be in the

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central one-third of the TFC.

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Let's do a little bit of scrolling.

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A close-out and scroll for you.

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117 00:05:29,330 --> 00:05:31,950 Central one-third looks great, but if you had

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a tear there, it would be vertical.

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That'd be a 1A or 1B,

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which this is, would be a peripheral

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TFC tear.

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A 1C would be a distal tear, perhaps

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involving one of the ulnar carpal ligaments,

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like the ulnar triquetral ligament.

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There's a Palmer one and a dorsal one.

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I'll show you those ligaments in a moment.

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And then, of course, if you got an A, B,

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and C, usually you have a D, and that is

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the origin or attachment to the radius.

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Now, that is not a tear.

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That is cartilage and some capsule.

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That is not a tear, that is cartilage,

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and that is cartilage of the ulna.

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So now let's look at our sagittal.

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Because the ulna is rotated dorsally, these

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attachments are going towards the ulna,

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and look at how swollen everything is.

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If I really window it hard, look at how swollen

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that is compared to the palmar aspect of the wrist.

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These are ulnar carpal ligaments going to the

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palmar radial ulnar ligament, which is right here.

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And these are dorsal attachments.

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There are innumerable ones.

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We're not outlining them right now.

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These are dorsal attachments, going

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to the dorsal radial nerve ligament.

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But all of these tissues are swollen.

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So in summary, palmar classification system

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Roman numeral I,

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A Central, B Peripheral.

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152 00:06:57,890 --> 00:06:58,320

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154 00:06:59,150 --> 00:07:00,320 That's what we have here.

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C, distal.

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157 00:07:03,040 --> 00:07:04,630 We probably have some component of

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distal involvement and dorsal involvement

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here, but that's not the main component.

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161 00:07:08,940 --> 00:07:14,140 And D, attachment to the radius, which almost never detaches.