Pseudogout

Question 1

Define:

Answer 1

• Arthritis associated with deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the joint cartilage
• Also causes acute monoarthropathy typically of larger joints in elderly patients
• Also known as acute CPP crystal arthritis

Question 2

Aetiology:

Answer 2

• Usually spontaneous and self-limiting but can be provoked by illness, surgery or trauma
• CPPD crystal formation is initiated in cartilage located near the surface of chondrocytes
• It is linked with excessive calcium pyrophosphate production
• This abundance of calcium pyrophoshpate leads to the formation of CPPD crystals
• Shedding of crystals in to the joint cavity leads to acute arthritis
• Most causes of joint damage predispose to pseudogout (e.g. osteoarthritis, trauma)

Question 3

Rare conditions that increase the risk:

Answer 3

o Haemochromatosis
o Hyperparathyroidism
o Hypomagnesaemia
o Hypophosphatasia

Question 4

Precipitating factors:

Answer 4

o Intercurrent illness
o Surgery
o Local trauma

Question 5

Epidemiology:

Answer 5

• 2 x more common in WOMEN

* More common in the ELDERLY

Question 6

Symptoms:

Answer 6

• Acute Arthritis
o Painful
o Swollen Joint (e.g. knee, ankle, shoulder, elbow, wrist)

Chronic Arthropathy
o Pain
o Stiffness
o Functional impairment

Uncommon Presentations
o Tendonitis
o Tenosynovitis
o Bursitis

Question 7

Signs:

Answer 7

•	Acute Arthritis
o	Red 
o	Hot 
o	Tender 
o	Restricted range of movement 
o	Fever 

Chronic Arthropathy
o	Similar to osteoarthritis
o	Bony swelling 
o	Crepitus 
o	Deformity
o	Restriction of movement

Question 8

Investigations:

Answer 8

o High WCC in acute attacks
o High ESR
o Blood culture - to exclude septic arthritis

Joint Aspiration of synovial fluid
o Rhomboid, brick-shaped crystals
o POSITIVE birefringence
o Culture or Gram-staining to exclude septic arthritis

Plain Radiograph of the Joint
o	Chondrocalcinosis – CPPD deposition
o	Signs of osteoarthritis:
	Loss of joint space 
	Osteophytes 
	Subchondral cysts 
	Sclerosis