Pseudogout

Question 1

Define

Answer 1

arthritis associated with deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the joint cartilage

Question 2

Causes

Answer 2

Aka. Acute CPP crystal arthritis

Usually spontaneous and self-limiting, but can be provoked by illness, surgery or trauma

↘ Calcium pyrophosphate crystals are positively birefringent under polarised light

Cause → most causes of joint damage predispose to pseudo-gout (e.g. arthritis, trauma)
Also more rarely: haemochromatosis, hyperparathyroidism, hypomagnesaemia, hypophosphatemia

Question 3

Risk factors

Answer 3

↑age, hyperparathyroidism, hemochromatosis, hyperphosphataemia

Question 4

Symptoms

Answer 4

Acute Arthritis

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

Chronic Arthropathy

• Pain
• Stiffness
• Functional impairment

Uncommon Presentations

• Tendonitis
• Tenosynovitis
• Bursitis

Question 5

Signs

Answer 5

Acute Arthritis

• Red
• Hot
• Tender
• Restricted range of movement
• Fever

Chronic Arthropathy

• Similar to osteoarthritis
• Bony swelling
• Crepitus
• Deformity
• Restriction of movement

Question 6

Investigations

Answer 6

Bloods

• High WCC in acute attacks
• High ESR

Blood culture - to exclude septic arthritis

Joint Aspiration

• Rhomboid, brick-shaped crystals
• POSITIVE birefringence
• Culture or Gram-staining to exclude septic arthritis

Plain Radiograph of the Joint

• Chondrocalcinosis
• Signs of osteoarthritis:
• Loss of joint space
• Osteophytes
• Subchondral cysts
• Sclerosis