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MRIonline, welcome, Coronal Anatomy

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Intrinsics SL Scapholunate Ligament.

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It's an important one.

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Tears of this on plain film produce widening of the

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scapholunate interval, known as the Terry Thomas sign,

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because Terry Thomas had a big space between his teeth.

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At least, I think he did.

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In the coronal projection, the ligament has depth.

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It has a front, a volar component, a middle that's

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fairly long, front to back, an interosseous membranous

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component, perhaps the least important component,

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and the most important, strongest component, the

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dorsal component of the scapholunate ligament.

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So if you can remember, SLD, scapholunate dorsal

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strongest, LTV, lunate-triquetral ligament,

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volar strongest, that may help you in the future.

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So let's start out volarly.

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Or palmarly, where there is some augmentation

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from the radioscapho-capitate ligament and the

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short radiolunate ligament, transitioning into

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the volar aspect of the triangular fibrocartilage,

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which some say has a trapezoidal shape.

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Let me draw a trapezoid.

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Here's my trapezoid.

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And it kind of looks sort of trapezoidal if

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we go to the volar aspect of it right here.

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And that's augmented again by

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the short radiolunate ligament.

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As we transition into the membranous

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interosseous component, that is more triangular.

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And I don't think I need to draw a triangle for you.

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Everybody knows what a triangle looks like.

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It is common to see little bits or snippets

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of signal in the interosseous component.

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It's not uncommon for it to be perforated or

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fenestrated or to have asymptomatic tears.

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So I'm not particularly worried

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about signals that exist.

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in the central, mid, interosseous, membranous

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component of the SL ligament, especially if there's

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no arthritis, or synovitis, or widening here.

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Then we continue on dorsally, to the

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back, where the strongest component

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is seen as a more band-like structure.

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Here's our band.

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It's a pretty short band.

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I'm gonna draw right over right now.

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There's our short band.

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And that's the strongest component.

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Of the scapholunate ligament.

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We'll see it again in the axial projection.

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But perhaps it's best depicted when scrolling

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from back to front in the coronal projection.

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Let me do it one more time for you.

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From back to front.

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And we are triangular membranous component to front.

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There we are with the trapezoidal

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component of the scapholunate ligament.

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One of the most important

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intrinsic stabilizers of the wrist.