A fracture occurs when the force exerted on a bone exceeds the ability of the bone to absorb the force by deforming. Fractures in children are common—approximately one third of children will have a fracture by 16 years of age, with more boys experiencing fracture than girls.¹ This differentiation in fracture risk is apparent from 2 years of age. Before the age of 2 years, fracture incidence is equal and occurs at a rate of approximately 80/10 000 person years. For the UK, therefore, approximately 4800 infants will have a clinically evident fracture before their first birthday each year.

Some long-bone fractures may occur at birth² in association with events such as shoulder dystocia³; skull fractures may occur during forceps⁴ and ventouse delivery.⁵ Some may (uncommonly) occur as a result of clearly defined trauma such as road accidents.⁶ Most, however, fall into the “unexplained” category. This article reviews our current approach to identifying bone disease in the infant presenting with more than one unexplained fractures, and discusses the recognised disease processes that result in increased bone fragility.

The history should include inquiry into specific areas as listed in the box. The two most frequently recognised underlying disease processes causing bone fragility in infancy are metabolic bone disease of prematurity⁷ and osteogenesis imperfecta, and directed questioning is appropriate for these conditions. For premature infants, the features commonly associated with fracture are delivery at <28 weeks of gestation, necrotising enterocolitis, late (>30 days) establishment of full enteral feeds, conjugated hyperbilirubinaemia, chronic lung disease, and use of furosemide.^8,9 For a proportion of infants with osteogenesis imperfecta, there will be a family history either of osteogenesis imperfecta itself or of features that suggest osteogenesis imperfecta. The other elements of the history relating to the …