Lower limb acute joint injuries: when to refer for X-ray?

This article summarises the clinical decision tools available to help decide when acute lower limb joint injuries should be referred for plain film radiography. The Ottawa foot and ankle rules are a tool for deciding whether to refer a patient for X-ray or not. The rules are highly sensitive, gaining National Institute for Health and Care Excellence recommendation in the UK, although they have limited benefit in some patient groups, such as those with peripheral neuropathy. The Ottawa knee rules are highly sensitive but less specific than the Pittsburgh decision rules. Although the Pittsburgh rules are more specific, they have been less extensively investigated and, unlike the Ottawa rules, are not National Institute for Health and Care Excellence recommended. A major barrier to use of these rules in clinical practice is the concern of litigation, although National Institute for Health and Care Excellence recommendation should reassure clinicians and thus reduce the amount of unnecessary radiation exposure.