MRI of posttraumatic cyst-like lesions of bone after a greenstick fracture

Abstract

Posttraumatic bone-cyst formation is a known but rare process. Typical location is the distal radius, usually as a result of a greenstick fracture. The pathogenesis is unknown; however, subperiosteal migration of fat or hemorrhage with later absorption may cause cyst formation. We present the first reported case of MR imaging of this lesion. At MRI subperiosteal hemorrhage was found to be the cause of cyst formation.