Calcium Pyrophosphate Deposition (CPPD)****

Question 1

What is this also called?

Answer 1

Pseudogout

Question 2

What is damaged which releases calcium pyrophosphate?

Answer 2

Chondrocytes - a cell which has secreted the matrix of cartilage and becomes embedded in it.

Question 3

Presentation:

Symptoms? - 5

Where does it usually affect?

What other disease does chronic CPPD present like?

Answer 3

Hot 
Red 
Swollen 
Pain 
May be immobile

Knees - larger joints regardless

RA - symmetrical

Question 4

Risk factors:

What electrolyte, at low levels could cause this?

What chemical in the blood, at high levels, could cause this?

What endocrine disorder could cause this?

Answer 4

Hypomagnesaemia

Haemochromatosis

Hyperparathyroidism

Question 5

Investigations:

Joint aspiration is done to look for crystals. What type fo light is shone on the aspirate so you can see the crystals?

What else may you measure in the blood? - 4

Answer 5

Light microscopy - polarised - GO TO PAGE 549 TO SEE DIFFERENCE BETWEEN THIS AND GOUT

PTH
Calcium
Magnesium
Iron

Microscopic analysis in pseudogout shows calcium pyrophosphate (CPP) crystals, which appear shorter than MSU crystals and are often rhomboidal. Under a polarizing filter, CPP crystals change color depending upon their alignment relative to the direction of the red compensator.

Question 6

Management:

What pain relief is given? - 2

This is done both acutely and long term

What is the last option?

Answer 6

NSAIDs or steroids
Colchicine

Joint replacement