Validation of the Ottawa Ankle Rule in Blunt Ankle and Midfoot Injuries in a Trauma Care Centre in Nigeria.

Objectives: Ankle and midfoot injuries are common presentations in every emergency department. The Ottawa Ankle Rule was developed to reduce the need for unnecessary radiography. This study aimed to validate this rule in a population.

Materials and methods: This study recruited 110 patients in a single-trauma care centre presenting with closed ankle and midfoot injuries. All patients were examined using the Ottawa Ankle Rule by orthopaedic surgeons and findings were recorded before radiographs were obtained. The radiographs were interpreted by a consultant radiologist blinded by the clinical examination findings. This was the standard against which the Ottawa Ankle Rule was tested.

Results: The sensitivity of the Ottawa Ankle Rule protocol in ankle and midfoot injuries was 100% and 95%, respectively. The specificity was 37.2% for ankle injuries and 54.8% for midfoot injuries. The negative predictive value of the rule was 100% and 95.1% for ankle and midfoot injuries, respectively. Application of this rule would have led to a 31% reduction in radiography amongst patients in this study.

Conclusion: The Ottawa Ankle Rule is a valid decision-making tool for patients with closed ankle and midfoot injuries. It has a high sensitivity for detecting fractures with moderate specificity. Application of the rule can result in a significant reduction of; treatment costs, waiting times at the emergency department, and unnecessary radiation exposure to patients.