We retrospectively reviewed the clinical notes and radiographs of children with proven non-accident injury (NAI) who had sustained long bone fractures between 1997 and 2002, and compared them to the clinical and radiological appearances of 32 osteogenisis imperfecta (OI) patients, seen over the last 20 years, who sustained fractures before the age of one year.

In the five-year period, 501 children had NAI. Sexual abuse was involved in 35%, soft tissue injuries in 31%, head injuries in 26% and long bone fractures in 3.6% (18 children). The mean age of these 18 children was 11 months. Six had more than one fracture, and there were 29 fractures (15 femora, five humeri, three elbows, two forearms, two clavicles and two tibiae). Fifty-seven percent of fractures were diaphyseal and 43% were metaphyseal. There were only three metaphyseal buckle or corner lesions (distal femur). In none of these children were there radiological features of osseous fragility, i.e., osteopoenia, anterolateral bowing of the femur and tibia and gracile bones (thin bones with thin cortices).

Of the 32 OA patients, 23 were Sillence type I. There was a positive family history in 84% and 95% had blue sclera and Wormian bones. One patient was unclassifiable. All OI patients had fractures in the first year of life, 38% of them occurring perinatally. All had femoral fractures, with or without other fractures, and 90% were diaphyseal. Two or more features of osseous fragility were present in all type-III and 20 type-I patients. Three type-I patients and the unclassifiable patient had osteopoenia only, without bowing or gracile bones. Howeve, three of the four had a positive family history and all had blue sclera and Wormian bones.

In all patients, the differential diagnosis between NAI and OI could be made radiologically. The family history, blue sclera and Wormian bones were adjuncts.