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Dr. P here.

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3 00:00:01,580 --> 00:00:03,550 This is a 54-year-old woman who

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complains of pain in the medial aspect

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of her foot with a burning component.

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And, you know, whenever I hear the term

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burning, I always think of neurovascular,

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specifically neural disturbances.

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Entrapment neuropathy.

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So I'm, I'm really calling

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for tarsal tunnel syndrome.

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Looking in the region of the neurovascular

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bundle to see if there's anything there.

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And there isn't, at least in this dynamic

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static set of images, I've got a T1, a proton

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density fat suppression, and a T2 on the right.

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And this patient has an

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unusually shaped navicular.

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You can see the cornuate or arcuate shape that

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is generated, which is a type of dysplasia.

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And patients typically have a very broad

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footprint of the posterior tibial tendon.

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Such as we see here.

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And although the risk of PT tear,

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posterior tibial tendon tear, is not as

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high as the type 2 accessory navicular.

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Remember there are three types.

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Let's show them to you real quickly.

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There's one type where the tendon comes in.

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And you have an ossicle inside it,

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the ostibiale externum, it's nice

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and round and smooth and corticated.

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You've got the type where the navicular comes

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around and has kind of a jagged edge and

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then there's an extra piece of bone right

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here, the type 2, the most symptomatic,

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and then this one, the arc shaped one,

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the arcuate or cornuate navicular type 3.

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But type 3s still have a higher

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incidence of symptomatology than a

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normal foot without any symptoms.

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Any of the above, with the exception

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perhaps of the ostibial externum,

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which is often asymptomatic.

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So, this patient has a few other findings

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besides this obtuse, weird shape of

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the navicular, and that is the cysts.

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That have occurred in the navicular.

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So what are they doing there?

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There are a couple of possibilities.

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We do have some tendinous and ligamentous

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structures that run immediately underneath and

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because of the fat shape, perhaps these are

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sawing against the underbelly, the undersurface

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of the navicular creating intraosseous ganglia.

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Another possible explanation is altered

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mechanics of weight bearing due to the

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presence of this cornuate or arcuate navicular.

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So perhaps Bone in the dynamic

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setting of standing might do this.

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This happens more frequently in flat foot and

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indeed this patient, if we call up the sagittal,

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let's just call it up as one big giant image,

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indeed this patient does have flat foot.

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Let's go to it.

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Just a very, very straight calcaneus.

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There's almost no arch present there

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and we also see our cornuate or arcuate

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navicular with the cysts associated with it.

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Earlier, if you remember, I said most patients

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with various navicular syndromes, don't have

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PT tear, they certainly don't have rupture,

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they may have tendinopathy, this one has

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a little bit of focality, you can see some

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laminar signal right there, and then I'm

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going to draw over it because it's so subtle.

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This could be the tendon simply dividing

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into various branches, but it's not.

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It's a real finding, and that is

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a slit-like laminar tear of the

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distal posterior tibial tendon.

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So the diagnosis here is another type

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of os navicular syndrome, type 3, the

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arcuate or cornuate variant, with a tiny

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insertional posterior tibial tendon tear

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and some changes in the underlying bone.

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Let's move on, shall we?

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Dr. P out.