Can clinical prediction rules used in acute pediatric ankle and midfoot injuries be applied to an adult population?

BACKGROUND: Almost every patient who comes to an emergency department (ED) with the chief complaint of ankle or foot pain will receive a radiograph, but less than 15% will have a finding positive for ankle or midfoot fracture. In an effort to reduce the number of radiographs performed, clinicians have attempted to derive a set of maximally sensitive clinical prediction rules. Dayan et al (Acad Emerg Med. 2004;11(7):736-745) in 2004 derived a set of such rules for children. These rules have not yet been evaluated in the adult population. OBJECTIVE: The objective of this study is to apply the existing clinical prediction rules used to identify children with fractures after twisting injuries of the ankle to a population that includes adults. METHODS: This was a prospective observational study using convenience sampling. Patients older than 2 years presenting to the ED or associated urgent care center with the chief complaint of an ankle or foot injury were considered eligible for enrollment into the study. After informed consent was obtained, 11 physical examination variables were assessed. Radiographs were obtained and reported, and the radiograph results were noted on the patient's data sheet. Based on the radiograph results, sensitivity and specificity of each of the physical examination variables were analyzed. RESULTS: Sixty-eight patients were eligible, and 29 patients were enrolled after exclusion criteria were applied (median age, 34 years). Three patients were diagnosed with a malleolar zone fracture, and 2 patients were diagnosed with a midfoot zone fracture. Five indicators were found to be 100% sensitive for ankle fracture, and 2 indicators were 100% sensitive for midfoot fracture. CONCLUSIONS: The same indicators found to be predictive of high risk for fracture in a population of pediatric patients were found to be predictive in a population including adults.