Bone Response to Damage

()Map MUSCULOSKELETAL SYSTEM (Map)

Changes to normal structure

• • Damage to periosteum:
    • Invokes a hyperplastic reaction of the inner layer
    • Is painful
    • Exostoses can remodel or remain
  • Lifting of periosteum causes new bone formation below
  • Circumferential incision (e.g. during fracture)
    • Longitudinal bone growth results
    • May be only on one side where periosteum is damaged
      • Used by surgeons to treat angular limb deformities

Physis (Growth plate)

• Site of many congenital or nutritional bone diseases in the growing animal
• Open in neonates and growing animals
  • Chondrocyte proliferation balances cell maturation and death
• Closes and ossifies at maturity
  • Regulated by androgens
• If growth teporarily stops -> layer of bone seals the growth plate -> moves into metaphysis when growth resumes -> forms Harris lines