Pediatric fracture without radiographic abnormality. Description and significance.

With an expanding application of magnetic resonance imaging in acute musculoskeletal injury, an increasing number of occult traumatic lesions of bone are being identified. The authors describe the entity of fracture without radiographic abnormality, which as the name suggests is a bony injury not apparent on plain radiographs. The clinical significance and potential sequelae have not been defined in the pediatric patient. Accordingly, the purpose of this study is to describe and classify the entity of the pediatric fracture without radiographic abnormality and delineate its importance and appropriate management. Twenty-five children were seen primarily or referred to The Children's Hospital of Philadelphia after having sustained an acute traumatic injury; all refused to bear weight or use their extremity, and all had initial plain radiographs that were interpreted as normal. Subsequent magnetic resonance images of all 25 children showed an occult fracture. These included Salter-Harris fracture Types II (two patients), III (one patient), and IV (three patients), intraosseous epiphyseal fractures (18 patients), and a metaphyseal diaphyseal fracture (one patient). Four patients with intraosseous epiphyseal fractures ultimately sloughed a portion of their articular cartilage, as observed at arthroscopy. The decision to proceed with magnetic resonance imaging in the evaluation of a child who refuses to use an extremity depends on many variables. However, magnetic resonance imaging has proven useful in revealing fractures without radiographic abnormality and in ruling out other pathosis.