Crystalline Arthritis (Calcium Pyrophosphate Dihydrate Crystal Deposition Disease)

Question 1

While the cause of CPPD is unknown, what are some diseases that have been linked to CPPD?
• what is the number one risk factor for CPPD?

Answer 1

AGE is the number 1 risk factor for CPPD?

Note these diseases are only believed to cause a minorty of CPPD.

• Hyperparathyroidism
• Hemochromatosis
• Gout
• Hyophosphatasia
• Hypomagnesemia
• ochronosis

Question 2

What are 3 ways in which CPPD may manifest?

Answer 2

• *1. Chondrocalcinosis** - asymptomatic disease
  2. Deposits in ligaments, tendons, and synovium
  3. May mimic other arthritides

Question 3

T or F: like Gout there is a strong association between CPPD and renal disease and diuretic use.

Answer 3

FALSE, CPPD is not associated with renal disease or diuretic use

Question 4

When are people most likely to have a clinical event of pseudogout?
• how common is chrondrocalcinosis?

Answer 4

People over 50 are at risk of pseudogout with the highest incidence being between 70 and 75 years old.

Chondrocalcinosis has been shown in 50 percent of patients over 85

Question 5

Remember: Pseudogout can mimic just about any disease of the joints.

Question 6

What changes in this radiograph make it look like CPPD?

Answer 6

• Cystic changes in multiples carpal bones including the scaphiod and lunate with linear calcification on the ulnar side of the carpus. This is typical for chondrocalcinosis of CPPD

Question 7

What are the most commonly affected joints in CPPD?

Answer 7

• KNEES
• Carpals
• Sympysis Pubis

Question 8

What feature of CPPD is shown here?

Answer 8

Linear calcifications on the menisci of the knee and linear calcifications

Question 9

What feature of CPPD is shown here?

Answer 9

Calcification of the articular cartilage

Question 10

What feature of CPPD is shown here?

Answer 10

Calcification of the intercarpal joints and triangular ligament

Question 11

What feature of CPPD is shown here?

Answer 11

Clacification of the symphysis pubis fibrocartilage

Question 12

Although uncommon, what strong genetic links have been made between certain mutations and CPPD?
• role of this gene product?

Answer 12

Genetic predisoposition to CPPD may cause a much earlier age of onset.

GENES:
• ANKH gene on chromosome 5p encodes a transmembrane protein that plays a role in PPi transport

Question 13

Where do CPP crystals tend to deposit in CPPD?
• what is the reason for this deposition?

Answer 13

CPPD shows crystal deposition most commonly in:
Loose AVASCULAR Connective tissue matrices like hyaline cartilage, firbrocartilaginous menisci, and certain ligaments and tendons.

• CPPD is related to dysreguation in P and PP metabolism associated with aging and changes in chrondrocytes.

Question 14

T or F: CPPD may look like many other arhtropathies and may even be associated with fever.

Answer 14

True, remember gout can also sometimes be associated with fever

Question 15

***What key clinical feature of pseudogout can help you differentiate it from gout?
• What about differentiating it from osteoarthritis?

Answer 15

**Gout-Pseudogout DDx:
• Gout typically affects SMALL joint while pseudogout affects LARGE joints (most commonly the knee and less commonly wrist and ankle)

• Pseudogout hardly ever affects the first MTP joint**

OA-Pseudogout DDx:
• In OA MCPs, wrists, elbows, and glenohumeral joints are typiclally spared. This is not the case in pseudogout.