This 3-year-old child was known to have a genetic syndrome resulting in severe developmental delays, inability to move, hypotonia and wasting. You had been asked to review the child’s fractures to help determine whether they had been caused by abuse or underlying medical disease. On chest CT scan, a fracture was noted which was not visible on plain x-ray (Images 38a and 38b). A skeletal survey was ordered which shows multiple bones with decreased density and increased density in the metaphyses (Images 38c, 38d and 38e). https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig38a.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig38b.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig38c.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig38d.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig38e.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>
Can you identify the rib fracture on the chest CT? Can you correlate the plain x-ray findings with the CT findings?
Given the child’s genetic condition and disabilities, how would you evaluate the fracture identified? Is it abuse? Are there other potential reasons for the injuries depicted?
The chest CT depicts a fracture of the posterior lateral rib with periosteal new bone formation. The chest x-ray does not demonstrate the lesion, likely because the lung findings obscure the proper visualization. This fracture is concerning as there is no history as to why it occurred and the imaging does not demonstrate obvious bone disease.
The long bone findings identified in the skeletal survey suggest metabolic bone disease resulting from the child’s underlying genetic condition and immobility. 1 , 2 Given the child’s disabilities, there is increased likelihood that the rib fracture may have been caused by routine care and/or chest physical therapy. The child should be evaluated with serum chemistries to identify abnormalities in calcium, phosphorus or other bone metabolic abnormalities to further identify treatable causes of bone fragility. Steps should be taken to notify medical caregivers about the child’s increased risk of fracture given these concerns.