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Let's begin our anatomy discussion, by the way,

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at 3 tesla, in a neutral position,

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so the foot is not plantar flexed,

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which highlights the ligamentous anatomy.

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Usually, the ligaments or the tendons are the

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most important structures we're hunting for

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on an MR examination that's been requested.

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So we'll start out by looking at the most

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frequently injured ligament of the ankle,

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which is the anterior talofibular ligament.

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It's a small structure.

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It goes from the talus to the fibula,

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and it's sheet-like, so it has innumerable bands.

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At some point, it may look rather wispy

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and multibanded, and at other points,

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it'll have a single line that's about

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two to three millimeters in thickness.

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But it should be straight and it almost

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never ruptures from its fibular attachment.

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It usually tears near the taylor

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attachment or in the mid-substance,

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most commonly in the mid-substance.

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Now if we look at the second component of the

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lateral collateral complex of which the anterior

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Talofibular ligament, also known as the ATAF or

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ATFL, the most frequent to tear, is, the second

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component, is the calcaneofibular ligament.

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Now, in slight plantar flexion,

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the calcaneofibular ligament is a little

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easier to see, but we do see it here.

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And it contributes to the

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floor of the peroneus fossa.

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There it is.

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And you can sometimes track it

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towards the fibula, right there.

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You can see it at least go up towards the fibula.

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There it is, a little better

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seen on the T1 on your left.

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and the T2 on your right.

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So if there's an anterior talofibular

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ligament, there it is, there should be a

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posterior talofibular ligament, and that one's

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going to be in the back, and there it is.

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The posterior talofibular ligament and its

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accompanying structures, like the transverse

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tibiotalar ligament and the intramalleolar

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ligament, which are kind of crossover

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ligaments between the high and the low ankle.

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will be better depicted in the coronal projection.

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But for now, simple, simple,

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the posterior talofibular ligament, a big,

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fat, strong, bulky ligament, never

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tears unless you dislocate your ankle.

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If that thing tears, you've got a major injury.

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So frequently you don't have to worry so

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much about it, except in athletes that

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do a lot of toe pointing and who does

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a lot of toe pointing ballet dancers.

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So in ballet dancers, it may not rupture.

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But it receives a lot of repetitive trauma,

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which may result in impingement and tears

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of some of the sub ligaments of this area

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that we'll discuss a little bit later.

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So we've got three important ligaments on the

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lateral side, the lateral collateral, the anterior

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talofibular ligament, the most common to tear.

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The second most common to tear,

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the calcaneofibular ligament,

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which we don't see in its entire course.

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But we see it going towards the fibula,

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forming the floor of the peroneus fossa,

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and finally, the strong, powerful, almost never

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tearing, posterior talofibular ligament.