Rationalising requests for x-ray examination of acute ankle injuries.

Radiographs of injured ankles represent about 1 in 50 of all radiological examinations. The notes and radiographs of 100 patients with ankle injuries were reviewed, and the films of a further 93 patients who had ankle fractures treated by immobilisation were also scrutinised to assess the presence of absence of soft tissue swelling over the malleoli. Any accompanying radiographs of the foot requested at the same time were also studied. In 65 of the 100 cases of ankle injury there was no soft tissue swelling, and none of the patients had a major fracture, while 92 of the 93 patients with a major fracture had soft tissue swelling at the level of the malleoli. In 32 of the 100 cases of ankle injury foot radiographs had also been requested, but only three foot injuries were found. If the simple maxim of "No swelling adjacent to a malleolus, no radiographs" were applied radiography of twisted ankles could be reduced by as much as two-thirds. Moreover, if this maxim included the rider "and no routine foot films" the total casualty radiographic work load could be reduced by 8%.