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Welcome to MRI Online, coronal evaluation

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of hyaline cartilage anatomy, and we've

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got lots of it, and it looks terrific.

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The hyaline cartilage is gray or

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intermediate on the T1-weighted image.

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You can see the capitate hyaline

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cartilage, a slit of dark signal, and

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then the adjacent scaphoid, capitate side

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of hyaline cartilage.

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So this is scaphoid cartilage, thin slit of collapsed

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capsule, and hyaline cartilage of the capitate.

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And so the same thing exists over here

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in the hamate, where we have a beautiful

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depiction of the hamate cartilage.

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If you add up the normal cartilage of the wrist

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from two adjacent bones, it's usually about

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2.5 millimeters on average.

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Now, one thing that's helpful to look at, especially

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as an indirect sign of instability, any kind of

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instability, whether it's radial ulnar instability,

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scapholunate or lunotriquetral instability,

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or midcarpal space instability, is the thickness of

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the cartilage, the presence or absence of erosions

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or swelling, defects, and adjacent synovitis.

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These indirect signs are invaluable

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in telling you what's going on.

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The hyaline cartilage of the scaphoid

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fossa is a terrific marker for the

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early development of slack wrist.

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The hyaline cartilage of the radial side of

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the ulna and of the base of the ulnar side

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of the lunate wear out early on in patients.

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that have ulno lunate impingement or abutment syndrome.

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Patients with failure of this ligament may

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develop erosions in the scapholunate space.

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Patients with lunato triquetral instability

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may develop erosions in this space and

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rarely will you have a situation where the

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ligament is sick and the cartilage is normal.

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So this indirect sign is reliable.

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Let me return for a moment to A brief

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discussion of this cartilage right here.

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This is the cartilage that's going to tell you,

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along with the triangular fibrocartilage, whether

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you have abnormalities of variance between the ulna

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and the radius with ulno lunate abutment syndrome.

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And that's a subject for its own vignette.

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Variance of the ulna relative to the radius.