Now that we've completed discussion of gout,
which by definition is accumulation of what?
here we'll take a look at what's
known as calcium
pyrophosphate deposition disease,
You probably, commonly, in med school,
and in your medical career, have come
across a being pseudogout.
I'll tell you why I want you
to stay away from that,
because you need to understand
the actual pathology.
So what is pseudogout?
Well, pseudogout is not the
accumulation of uric acid,
so therefore, it's not gout.
So what is it? It's accumulation of calcium.
Focus on that. The full name
and the full name is calcium pyrophosphate
deposition disease. CPPD. Correct?
I told you to focus on calcium, why?
Because presentation, especially
when I give you the X-ray.
I'm going to show you
that there's going to be accumulation
What color does calcium appear on X-ray,
opaque or loosened?
So, I'll show you something
And while we go through this,
obviously, you're going to compare
this with the gout,
and you'll see just how simple it is.
Pathogenesis. Deposition of the
Most commonly, where? Oh, I remember.
In gout, where was the patient
complaining of pain acute?
In the big toe, right?
Watching the football game,
"Oh, it hurts. Stop it."
Yeah. Well, this is
the large joints that you're looking
for here in pseudogout
Next, I told you to focus on calcium.
Chondral means cartilage.
So in your joints, such as a knee and such,
you're going to accumulate calcium,
It's the meniscus of the knee,
maybe the pubic symphysis,
and maybe the wrists. These are large joints.
Now, there are associations
Metabolic disorders such as
What does that mean to you?
Oh, increased calcium. There you go.
Maybe hemochromatosis association.
Keep that in mind.
Could be hypothyroidism,
and Wilson's disease, in other words copper.
So there's important endocrine
or electrolyte association
that you want to keep in mind
with deposition of CPPD.
Signs and symptoms.
Patient, typically, presents with
acute symmetric arthritis.
What was it in gout?
It was one toe, podagra,
These episodes are usually
triggered by surgery,
secondary to volume shifts,
or even severe illness. Keep that in mind.
And then, so we talked about how
you could have pseudogout.
In other words, the pain could be acute.
It could be monoarticular.
However, over a long period of time,
let's say that the knee has been
The presentation now kind of feels
like a wear-and-tear type of pain.
In other words, patient wakes
up in the morning,
feels a little bit of stiffness,
but it's less than…
less than 1 hour, maybe less than 30 minutes.
Seems like osteoarthritis, but it's not.
On X-ray, you find calcium accumulating
on the cartilage.
So therefore, in chronic…
we then call this pseudo osteoarthritis.
Or the pain might > 1 hour,
and this may seem like
We call this pseudo rheumatoid arthritis.
We haven't talked about
rheumatoid arthritis yet.
But this is all about depositing calcium
pyrophosphate, acute, chronic.
So we have pseudogout or we
or pseudorheumatoid arthritis.
Keep that in mind for chronicity.
The calcium pyrophosphate.
Now, these are rhomboid.
What shape were the gout crystals?
Uric acid crystals?
They were needle-like, weren't they?
What was the type of light that we used
to identify the needles of gout?
Remind me again, in gout, those
uric acid crystals,
were they negative or positive birefringent?
In gout, it was negative birefringent.
If it was negative birefringent
on polarized light,
on parallel, was it yellow or blue?
Completely different when
we talk about CPPD.
Here, we slightly positively birefringent
under polarized light.
Now if we use parallel light for positive,
guess what color that is?
So, the biggest difference, therefore,
on polarized light has been,
on parallel light, it will be
and you know it because on
parallel, it will be blue.
If done parallel, it's yellow.
That means it's negative.
Number one differential, gout.
Is that understood? If not,
make sure you repeat what I just mentioned.
Next, we'll talk about calcium.
Once again, here,
it is not uric acid, it's calcium.
So this may then appear in soft tissue
as well. What color is calcium?
White on X-ray, in other words, opaque.
Management of CPPD acutely would be that
similar to gout acute,
where we have anti-inflammatory
drugs such as NSAIDs.
You want to try to take care
of the prophylaxis
and prophylaxis usually
will be with colchicine.
Remember, associations that you could have,
Wilson's and such,
the associations take care of the
underlying issue, as well.