ABSTRACT
An 8-month-old boy was brought to the emergency department (ED) as the parents noticed his wrist was swollen which they thought was causing him pain. He was the third child of unrelated African parents, his siblings being 18 months and 3 years old. They were all exclusively breastfed. He had not yet been weaned from breast milk. On examination both his wrists were swollen and uncomfortable, but there were no other significant findings. The ED doctor considered concealed trauma so he requested a wrist radiograph (Image 83). https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig83.jpg"/>
What do you see (or not see)?
What is the most likely diagnosis?
Are there concerns about non-accidental injury?
188The image shows no fracture. However, the metaphyses are widened and splayed. They are irregular with loss of the normal dense end plate in the radius and ulna (the distal ulna is often slightly irregular on normal images). There is increased gap between the radius and the carpal bones due to unossified matrix. There is a trace of periosteal reaction along the metacarpals suggesting early healing reaction.
This boy has rickets. Rickets does still exist and is usually seen with prolonged breastfeeding without formula or vitamin supplementation. There is an increased risk if the mother herself has dietary deficiency, has had multiple pregnancies close together and all the children were all breastfed or had poor exposure to sunlight, related to culture and country of origin. The boy’s bone biochemistry was abnormal (calcium, phosphate, alkaline phosphatase [ALP], parathyroid hormone [PTH] and vitamin D). He responded to improved diet.
The role of ‘biochemical rickets’ in non-accidental injury is an area of controversy. This issue arises when there are fractures in the presence of a radiographically normal skeleton, but the bone biochemistry results are mildly abnormal or the vitamin D levels are suboptimal. Fractures do not occur commonly in rickets and are usually ‘insufficiency’ fractures. Generalized radiographic changes are usually evident when rickets is sufficiently severe to predispose to fracturing. 1 Other disorders that may mimic non-accidental skeletal injury include
Copper deficiency (rare) with metaphyseal spurs and reduced bone density
Syphilis with metaphyseal ‘lytic’ areas
Scurvy with osteoporosis and subperiosteal haematomas simulating fracture healing
