Foot and ankle injuries are common injuries which are now almost universally assessed using the Ottawa Foot and Ankle Rules. Despite the use of such decision rules, less than 22% of Ottawa positive patients presenting to the emergency department have fractures (high sensitibity, low specificity). The poor specificity of the ankle rules means that about 80% of patients who have an x-ray do not have a fracture, with many patients exposed to unnecessary ionising radiation. An alternative approach is to use ultrasound (US).
In a study of Canagasabey et al. (2011) US had a sensitivity of 90.9% and a specificity of 90.9% for the diagnosis of significant foot and ankle fractures. Therefore, they conclude that US shows great potential for the assessment of foot and ankle fractures and can efficiently identify patients who would require radiographic evaluation.