Bone-in-Bone Pattern

Bone-in-Bone Pattern

A descriptive term for a double bone pattern which may be normal in the infant vertebral body at 1–2 months of age, with peripheral decreased bone density and retention of a sharp cortical outline; it may represent postnatal bone remodeling; the pattern is abnormal when there is a symmetrical increase in bone density accompanied by a lack of ‘tubulation’. When limited to the end-plates of the vertebrae, the radiologic appearance results in a sandwich vertebra, or, if more extensive, a miniature ‘vertebra within a vertebra’, typical of osteopetrosis
DiffDx Osteomyelitis, sickle cell infarction with periosteal elevation, osteolysis, endosteal absorption and neo-osteogenesis along the inner cortex of the medulla, Gaucher’s disease, cleidocranial dysostosis, post-irradiation changes in children, or Thorotrast-related (of historic interest only)