Minimising negative ankle and foot X-rays in the Emergency Department -- are the Ottawa ankle rules good enough?

To review fracture rates in patients who had X-rays of either the ankle or foot or both in the Emergency Department of a district hospital.

A retrospective review of 2589 Emergency Department patients who had X-rays of the ankle or foot or both over a 12-month period.

There were 1199 ankle X-rays taken of which 193 (16%) showed a significant fracture. There were 1081 patients who had a foot X-rayed of which 165 (15%) showed a significant fracture. Younger patients had more X-rays but older patients were more likely to have a fracture. There were 309 patients who had an ipsilateral ankle and foot X-rayed at the same time, and of these 42 (14%) showed one fracture and just two (0.6%) showed a significant fracture of both ankle and foot.

The approach to X-raying ankle and feet in this study is probably widespread, and Ottawa Ankle Rules still seem to be of limited use in diagnosing fractures. This low yield of positive X-ray could be accepted or a more sophisticated ankle rule introduced.