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Welcome to MRI Online, coronal anatomy intrinsics,

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the dreaded lunotriquetral ligament.

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Why is it dreaded?

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There's some controversy about its anatomy.

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It's tiny.

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It can be hard to see.

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You need small fields of view.

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And this is the ligament where you may need to

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use arthrography maybe one out of five times.

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The lunotriquetral ligament is perhaps

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best seen in the mid coronal projection.

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It looks like a mustache or the Salvador Dali mustache.

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It projects up into the capsular

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slit, which should be collapsed.

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So in my experience, the best sign,

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actually, of lunotriquetral ligament

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injury is assessing the joint space.

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If the joint space is pristine and smooth, there's no

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fluid, and the capsule is collapsed, the likelihood

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of a lunotriquetral ligament tear is almost zero.

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Now let's scroll a little bit, and we are moving

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towards the dorsal aspect of the LT ligament.

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Thank you. And we said earlier that

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the volar aspect, which is right here,

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is a little bit stronger or thicker.

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Now that's probably true anatomically, but the more

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important stabilizer is still, like in the SL region,

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the dorsal aspect, right here, of the LT ligament.

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There have been many descriptors about the

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different shapes volarly, or palmarly, and dorsally.

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Throw those out.

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It's not worth memorizing them.

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Just realize that as you get more dorsal, the

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ligament gets more amorphous, and as you get more

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palmar, the ligament also gets more amorphous.

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There's attachments to these

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ligaments, as the onocarpal attachment.

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That one was volar, and this one

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right here, there, is dorsal.

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They're a little hard to see, I admit that.

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I think you can see it better right here.

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The dorsal onocarpal attachment.

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The lunotriquetral ligament also

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has another important variation that is

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not depicted here, and that's clefts.

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The clefts can be partial, or they can

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either even bisect the entire ligament.

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So the ligament could look something like this.

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The ligament comes down, looks like a mustache.

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Or, a triangle with a little point on top.

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I'm gonna make it a little bigger.

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Blow it up.

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And it could have a partial cleft in the middle of it.

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I'll make the cleft yellow.

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Or it could have a full cleft all the way through.

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And separate the ligament into two halves.

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Now that can be particularly confusing.

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But one thing that will help you.

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Look at the joint.

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First of all, this cleft will be pretty symmetric.

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It usually won't be off eccentrically

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to one side or the other.

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And the joint will still look pristine.

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So when you have these clefts, which

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are common in the LT ligament, look at

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the LT interval for supportive evidence.

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Another potential pitfall in assessing both

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the SL and the LT ligaments is that they

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generally don't attach directly to the bone.

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They're attaching to cartilage.

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So if there's a little bit of cartilage irregularity,

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or puffiness, or swelling, or synovitis, it

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may appear as if the ligament is attaching

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to a fluid-like area and not really attached,

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when in fact, it's simply attached to a swollen

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structure that it's supposed to be attached to.

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So, remember that these ligaments often do not

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directly attach to cortical bone, they attach

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to hyaline cartilage and capsular reflections.

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That's my story.

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For the dangerous, tough-to-diagnose,

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invariably shaped lunotriquetral.