Utility of Ottawa Ankle Rules in an Aging Population: Evidence for Addition of an Age Criterion

The Ottawa ankle rules (OAR) indicate that any patient with the inability to ambulate up to four steps or with tenderness at either malleoli should receive diagnostic imaging for an acute ankle injury. Current trends indicate that health care providers tend to order more images in practice than necessary according to OAR. The purpose of this study is to analyze OAR in geriatric versus nongeriatric patients. Secondarily, we hope to refine these guidelines for ankle imaging in the hopes that health care providers will be comfortable in adhering to these guidelines more strictly. A retrospective chart review was conducted of 491 adult patients with an average (± standard deviation) age of 54.4 ± 21.6 years (range 18 to 96). Applying the current OAR resulted in a sensitivity of 98.2% and a specificity of 58.6% in this entire cohort. The calculated sensitivities were comparable between the nongeriatric and geriatric cohorts, at 98.60% and 97.99%, respectively. The specificities varied between the nongeriatric and geriatric cohorts, at 60.13% and 33.33%. We propose new guidelines that would mandate imaging studies for any patient ≥65 years of age presenting to the emergency department with ankle pain. When applying these proposed guidelines, the sensitivity of the entire study population was found to be improved to 99.0%, whereas the specificity dropped to 56.7%. The slight decrease in specificity was deemed acceptable because these guidelines are meant to be used as a screening tool and because the risk of OAR not correctly identifying ankle fracture (2% of geriatric fractures) was completely mitigated in the geriatric population.