G68 Case series: RIB fractures in infants with osteogenesis imperfecta

Abstract

Aims Osteogenesis Imperfecta (OI) is an inherited disorder of type 1 collagen that results in a predisposition to fractures. Although non accidental injury (NAI) is far more common (incidence 24/1000 vs. 1/10–20,000), an inherent predisposition to bone fragility must be excluded in an infant presenting with an unexplained fracture. In 2013 a case series of fractures in 68 Children with OI reported that 15 (22%) of patients sustained rib fractures – 13 occurred in the perinatal period; 2 after 12 months. None sustained rib fractures during the first year of life and the authors concluded that rib fractures in infants remains highly associated with physical abuse and does not support OI as an underlying cause. Our case series aims to demonstrate that rib fractures can occur in infancy in OI. Methods Retrospective analysis of all 150 patients with OI at a tertiary centre to identify rib fractures sustained in the first year of life, excluding those with rib fractures at birth. All X-rays were reviewed by a paediatric radiologist with expertise in NAI and OI. Results 4 patients with OI were identified as sustaining rib fractures, none with a significant history of trauma. One child was initially misdiagnosed as NAI after presenting aged 6 weeks with an unexplained femoral shaft fracture. He had a normal skeletal survey and no other clinical features to suggest OI. 3 weeks later, while still in hospital, he sustained posterior rib fractures and was later found to have a mutation in COL1A1. A second child with genetically confirmed type V OI, presented at 9 months with a femoral shaft fracture and was found to have dysplastic ribs with healing posterior fractures and shortened dysplastic long bones. The other 2 patients who were suspected antenatally as having OI, were born with multiple fractures and phenotypic features, but did not sustain rib fractures until 6 months and 11 months respectively Conclusion Contrary to previous opinion, rib fractures can occur in OI within the 1st year of life and this should be considered in infants presenting with this injury, especially if they have other features suggestive of the condition.