Unusual Femur Stress Fractures in Children With Osteogenesis Imperfecta and Intramedullary Rods on Long-term Intravenous Pamidronate Therapy.

In this report, we describe 6 children with osteogenesis imperfecta with unusual stress femoral fractures. All children were on long-term cyclic pamidronate treatment. All fractures occurred without trauma or with minimal trauma and were located in the subtrochanteric or the diaphyseal regions of the femur over preexisting intramedullary rods. These fractures have very similar features to the reported minimal trauma atypical femoral fractures in adults on long-term bisphosphonate treatment. These fractures raise concerns about the role of prolonged remodeling suppression and microdamage accumulation and the risk of increased bone fragility.