Calcium Pyrophosphate Dihydrate
Crystal Deposition Disease
CPPD

• Terminology
  • Chondrocalcinosis – calcification of hyaline (articular) cartilage or fibrocartilage (menisci) or ligaments
    • Usually but not always due to calcium pyrophosphate
      • May also be seen with oxalosis
  • Pseudogout is an older clinical term referring to acute pain (similar to gout) but without response to the usual treatment for gout
  • CPPD – Deposition of crystals in the joint with or without chondrocalcinosis
• Most common crystalline arthropathy
• Prevalence
  • Widespread in older population
  • M:F = 3:2
• Clinical findings
  • Intermittent attacks
    • May be mono-articular or polyarticular (more often)
      • Pain
      • Redness
      • Swelling
• Types
  • Frequently occurs in association with osteoarthritis
  • Aging process with no known etiology
  • In association with metabolic diseases
    • Hyperparathyroidism
    • Hemochromatosis
    • Hypothyroidism
    • Hypomagnesemia
    • Hypophosphatasia
    • Ochronosis
• Calcium pyrophosphate crystals may be recovered from synovial fluid (most often) or within leukocytes
  • Characteristic weakly positive birefringent diffraction pattern
• Location
  • Knee
    • Especially meniscus
    • Cartilage of patellofemoral joint
  • Wrist
    • Triangular fibrocartilage in distal radioulnar joint bilaterally
  • Pelvis
    • Sacroiliac joint
    • Symphysis
  • Spine
    • Annulus fibrosis of lumbar intervertebral disk
      • Never in nucleus pulposus as in ochronosis
  • Shoulder
    • Glenoid
    • Hip
      • Labrum
    • Elbow
    • Ankle
    • Acromioclavicular joint
• Imaging Findings
  • Pyrophosphate arthropathy resembles osteoarthritis
    • Joint space narrowing
    • Extensive subchondral sclerosis
  • Polyarticular chondrocalcinosis (in fibro- and hyaline cartilage)
  • In knee, disproportionate narrowing of patellofemoral joint
    • Large subchondral cysts are a hallmark
    • Numerous intra-articular bodies
      • Fragmentation of subchondral bone
  • In hand, beaklike projections from 2nd, 3rd metacarpal heads
    • Subchondral cysts (esp. carpal bones)
    • Unusual distribution of disease (radiocarpal/ulnar joint, patellofemoral joint)
    • SLAC - scapholunate advanced collapse
      • Caused by laxity of the ligaments and malpositioning of the scaphoid and lunate
      • May develop in 25% with CPPD but also occurs for other reasons
      • Radio-scaphoid, but not radio-lunate, joint is narrowed
      • Usually have a deep concave scaphoid fossa in distal radius in CPPD as opposed to SLAC from trauma

CPPD of hand and wrist - upper photo shows hook-like projections arising from radial aspect of metacarpal heads;
lower photo shows SLAC-scapholunate advanced collapse with characteristic indentation in distal radius by scaphoid bone. There is also chondrocalcinosis of the triangular fibrocartilage of the distal ulna.

• Treatment
  • Oral anti-inflammatory drugs (NSAIDs) and corticosteroid joint injections successful in shortening the length of pain and dysfunction of acute attacks of pseudogout
  • Treatments to prevent attacks, such as colchicine, may be effective
  • No treatment is available to dissolve the crystal deposits
  • Controlling inflammation helps to halt the progression of joint degeneration

Imaging of the Wrist and Hand: Gilula and Yin, W.B. Saunders, 1996