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<v ->Now let's talk about intracapsular ligaments

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in a little bit more detail.

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If you wanna go ahead and characterize the types

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of ligaments that are related to joints,

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you're gonna end up with three categories.

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I've numbered them here.

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This is my drawing.

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Think of this, perhaps as a coronal section of the knee.

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So we're dealing with the femur in red, the tibia here.

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Number one are the primary capsular ligaments

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and the example I would show you

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is the medial collateral ligament of the knee shown here.

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These capsular ligaments are seen

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around all synovial joints.

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In certain positions, they add actually look like

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synovial folds within the joint.

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The second type of ligament we can see is called

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an accessory intracapsular ligament

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and in the knee, of course, what we'd be dealing with

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would be the anterior and posterior cruciate ligaments,

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as shown in these sagittal sections.

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Typically these ligaments,

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these accessory intracapsular ligaments,

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are intracapsular, but extra synovial

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and yet there may be a little holes within them normally,

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such that synovial fluid can bathe

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the accessory intracapsular ligaments.

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The third type, labeled number three,

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as an accessory extracapsular ligament

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and what it does in simple terms,

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it often brings a third bone into the articulation.

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For example, here in the knee,

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we deal with a fibular collateral ligament,

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which is extracapsular, this is a coronal section,

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and it brings the fibula in as part of the knee joint.

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Think of the ankle, for example,

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we have the calcaneofibular ligament,

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which would be a similar accessory extracapsular ligament.

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So in the knee, when we deal

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with the intracapsular ligaments,

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we're dealing with ligaments that are intracapsular,

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typically extra synovial,

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and certain problems can develop within them.

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In the knee, we deal with an entity

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known as cystic degeneration,

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in which we get delaminated clefts present

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within the substance of the ligament

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parallel to the collagen fibers.

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This is what it might look like in a specimen.

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Now, these clefts may enlarge, particularly in older people,

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producing a condition known as cystic degeneration.

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This is really degenerative pairs

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that are delaminated in nature

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within that particular ligament.

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It's said that in the anterior cruciate ligament

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it's the posteriolateral bundle

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that's more commonly involved.

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I've seen examples where both bundles are involved.

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The posterior cruciate ligament may show this

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and you may see this in other joints as well.

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One of the interesting aspects

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of the anterior cruciate ligament

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is its relationship to the anterior root ligament

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of the lateral meniscus.

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These are intimate and their attachment sites may be shared.

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So when you have cystic degeneration

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of the anterior cruciate ligament,

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you may end up with cystic changes

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involving the anterior root ligament

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of the lateral meniscus.

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I'm just gonna show you quickly

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some examples of what cystic degeneration looks like.

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Not as dramatic in the two images on your left,

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very dramatic in the three images on your right.

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And what may occur is that some of these cystic changes

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may occupy the nearby bone.

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More commonly it's the tibia that may demonstrate the cyst,

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but similar abnormalities may involve

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the intercondylar region of the distal femur.

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The same process can be seen

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with an intracapsular ligament in the hip.

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And this of course is the Ligamentum Teres

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that passes through the hip joint and attaches to the femur,

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as you know, in the foveal region.

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And it too may undergo cystic degeneration,

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shown here in a transverse section and image,

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as well as histology.

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We see this more commonly in older persons,

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it can lead to internal impingement of the hip.

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Here's another example,

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showing you enlargement of this ligament

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at its femoral attachment.

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Look at the enlarged cystic region now,

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here in the fovea of the ephemeral head.

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So this can occur and can be symptomatic.