Case 24

A 2-year-old child was admitted to the hospital with a chest infection. On clinical examination, the child was well kept, thriving and socially normal. There were no dysmorphic features, and the sclerae were white. The fontanels were normally sized. The chest x-ray showed a single healing rib fracture. Skeletal survey showed wormian bones (Images 24a and 24b) and there was evidence of systemic bone disease in terms of abnormalities of bone shape and radiological density. There was a fracture of the humeral condyle (Image 24c). Biochemical testing showed a normal vitamin D level and an elevated alkaline phosphatase consistent with a healing fracture. The parents were adamant that they had not injured their child. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig24a.jpg"/> https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig24b.jpg"/> 54 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig24c.jpg"/>

What would you do next?

Does the injury type or signs of systemic bone disease exclude abuse as a cause of the fractures?

56A full family history should be taken. On detailed questioning the mother said that she had a number of fractures as a child and that she has always been ‘double-jointed’; she had suffered from back pain that had limited her daily activities and had been seeing a chiropractor. You should consider requesting an x-ray of the mother’s back and advise her not to visit the chiropractor until this has been reported. You should also think about genetic testing for type I collagen defects. Osteogenesis imperfecta (OI) not infrequently presents in mild cases like this and many cases are initially suspected of being cases of non-accidental injury. Many families remain angry about these suspicions for a long time.

There were signs of radiological osteopenia in this case but the fracture type is common after accidental falls in normal children. Radiological osteopenia requires substantial loss of mineralized bone tissue (likely >30%) and bone density measured quantitatively by dual energy x-ray absorptiometry is often in the normal range in older children with mild OI. However, despite this, some of such patients go on to develop vertebral crush fractures. Genetic testing for OI is indicated as there are several loci which have been implicated in classic OI types. ¹ Child abuse has been implicated as a cause of fracture in children with OI, although the presence of an underlying bone disease can alter the amount or types of force required.