Introduction

  • Scurvy is disease that results from vitamin C deficiency
  • Vitamin C (ascorbic acid) deficiency causes failure of collagen synthesis and osteoid formation
  • Results in osteoporosis and possibly spontaneous bleeding

Pathogenesis

  • Normal collagen synthesis depends upon the hydroxylation of proline and lysine for which vitamin C acts as a cofactor
    • Vitamin C deficiency prevents hydroxyproline and hydroxylysine formation
    • Produced collagen contains only ‘non-hydroxylated’ proline and lysine
    • The resulting collagen fibrils lack hydrogen bonding and lose mechanical stability
  • Bony pathogenesis consists of two parts
    • Failure to lay down bony matrix
    • Persistence of an unabsorbed calcified cartilage lattice
  • Cartilage cells of the epiphyseal plate multiply and orientate themselves normally 
  • Intervening matrix becomes calcified, but osteoblasts fail to lay down osteoid
  • Calcified cartilaginous matrix is not completely resorbed
  • Epiphyseal plate becomes widened and irregular
  • Spicules of calcified cartilage fracture and a very irregular radiologically dense zone arises at the junction of epiphysis and shaft
  • Failure of resorption of calcified cartilage also makes ring sign

Natural History

  • Onset at 6 months – 2 years
  • Rare in adults

Clinical Presentation

  • Infants are irritable and anaemic
  • Gums may bleed spontaneously
  • Haemorrhage near large joints may cause excruciating pain and tenderness
  • Fractures or epiphyseal separation may occur 

Imaging and Diagnostic Studies

  • Generalised bone rarefaction
  • Most marked in metaphyses of the long bone which may be deformed or fractured
    • Metaphyseal lucency (Trummerfeld Zone)
    • Metaphyseal corner fractures through the weakened lucent parts (Pelkan spurs) results in cupping of the metaphysis
  • Normal calcification in growing cartilage produces dense transverse bands :
    • At juxta-epiphysial zones (Frankel white line) 
    • Around ossific centres of the epiphyses (Wimbergers ring sign)
  • Zones of provisional calcification appear dense
  • Subperiosteal haematomas appear as soft tissue swellings or peri-osseous calcification 

Treatment

  • Large doses of vitamin C bring prompt relief