Physiologic periostitis describes the normal presence of smooth bilateral diaphyseal periosteal new bone in the humeri, femora or tibiae of infants aged 1 to 6 months. It can be observed in both preterm and term infants. The etiology is unclear but may simply relate to rapid growth.
- long bones: tibiae, humeri, and femora relatively equally affected
- diaphyseal smooth periosteal reaction which may extend partly into the metaphyseal region, but not to the end of the metaphysis
- always bilateral and usually symmetric in extent
- organized and lamellar 2
- often concentric around the bone but may predominate on one aspect
- when tibial, it is always seen along the medial aspect
- no fracture or metaphyseal corner lucency
- no flat bone involvement
Normal uptake is observed in contrast there is high uptake in trauma 2.