Imaging Case of the Week 21

It is 1am and you are seeing a 12 year old boy who has presented with a painful foot on the lateral aspect due to an inversion injury which was sustained when he fell off his skateboard earlier in the evening. The patient’s mother is very anxious to know if he can take part in a footie match the next day. You obtain an x-ray of the foot; what will your advice be to the mum?

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You have noticed the horizontal lucent line across the base of the 5th metatarsal. You are not too sure if it represents a normal unfused apophyseal line or a fracture base of the 5th metatarsal. What is your diagnosis?

[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]

This patient has an avulsion fracture of the base of the 5th metatarsal.

  • A fracture line will run transversely to the long axis of the metatarsal.
  • An unfused apophysis will be in line with the long axis of the metatarsal (usually between the age of 9-14).

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You will have to advice the mum that her son will not be able to participate in any sports for awhile. Treatment is a short leg walking cast for 4-6 weeks.