Saturday, July 28, 2012

Periostitis Differential Diagnosis

Periostitis is an important finding on a musculoskeletal imaging study. It represents inflammation within the periosteum, a layer of connective tissue which surrounds bone. Various forms exist, which typically reflect the aggressiveness of the underlying process. No good mnemonic here (Roentgen Ray Reader referenced below has one, but it is quite long), but the major categories are:

DiseaseNotes

Physiologic Periostitis
  • Appears around age 3 mos
  • Resolves by 6 mos

Caffey's Disease
  • Infantile cortical hyperostosis
  • Involves mandible
  • Occurs before 6 mos

Arthritis
  • Typically psoriatic or reactive

Pachydermioperiostitis
  • Autosomal dominant disorder 
  • Skin thickening

Fluorosis
  • Symmetric 
  • Sclerotic bones

Hypervitaminosis A

Infection (Osteomyelitis)
  • Involucrum - thick irregular new bone that forms from periosteum
  • Sequestra - avascular dead bone from cortical blood supply disruption

Fractures
  • Can be seen in regular fractures or stress fractures

Tumor
  • Osteosarcoma (Codman's triangle, sunburst)
  • Ewing's sarcoma (Lamellated, hair-on-end)
  • Chondroblastoma (age<20)

Eosinophilic granuloma

Hypertrophic Pulmonary Osteoarthropathy

Venous stasis
  • Thick, undulating reaction
  • Also see edema, phleboliths
Sunburst reaction of osteosarcoma
Source: AJR

References: