Gracile bones

Gracile bones refer to changes in the skeleton in which the bones are more slender than usual (over-tubulated) and occasionally deformed in other ways such as being abnormally curved. This may occur in a number of disorders and can occur with or without fractures.

Pathology

Etiology

• neurofibromatosis type 1
• immobilization/paralysis: often gracile bone matches area of paralysis
• muscular dystrophy
  • Duchenne muscular dystrophy 
• muscular atrophy
• rheumatoid arthritis (juvenile)
• osteogenesis imperfecta
• dysplasias (gracile bone dysplasias)
  • Marfan syndrome
  • homocystinuria
• hemophilia: will typically have gracile diaphyses with expanded epiphyses

The useful mnemonic for learning the causes of gracile bones is NIMROD.