Case Number 21:

A 53 year old woman presented with a one year history of a painful swollen left ankle which prevented full weight bearing. She attributed this to an episode of minor trauma in which she tripped and twisted the ankle. Radiologically there was no evidence of bony injury at the time of the incident.

Her past medical history included Crohn's disease, which had necessitated a small bowel resection for a stricture in 1982 but which had been quiescent for many years apart …