Degenerative Joint Disease

(DJD)

DJD in a horse (Image sourced from Bristol Biomed Image Archive with permission)
  • Osteoarthritis, osteoarthrosis
  • Due to acceleration of normal ageing process - wear and tear
  • Destructive disease leading to:
    • Loss of weight-bearing articular cartilage
    • Erosion, fibrillation of cartilage
      • Clefts in the cartilage, perpendicular to the surface
    • Complete exposure of underlying bone
      • Bone appears polishes, dense - eburnation
      • Radiographically - joint space reduction due to loss of cartilage
    • Osteophyte formation at joint margins
    • Remodelling of adjacent bone
    • Brown/yellow discolouration
    • Synovial hypertrophy
    • Capsular fibrosis
  • May affect one or multiple joints
  • May or may not be symptomatic
  • Pathogenesis:
    • Not entirely clear but linked to loss of proteoglycans and subsequent lubrication
    • Increased water content due to improper binding -> softening of cartilage = chondromalacia