Validation of the Ottawa ankle rules: Strategies for increasing specificity

Area of Science:

• Orthopedics
• Radiology
• Emergency Medicine

Background:

• Ankle and foot injuries frequently lead to radiological examinations.
• The Ottawa Ankle Rules (OARs) are used to guide imaging decisions.
• Reducing unnecessary radiation exposure and optimizing Emergency Ward (EW) costs are key concerns.

Purpose of the Study:

• To validate the Ottawa Ankle Rules (OARs) in a specific patient population.
• To identify additional parameters to enhance the specificity of the OARs.
• To decrease radiation exposure and improve cost-efficiency in the EW.

Main Methods:

• A prospective study over 9 months involving 148 patients.
• Sequential protocol including OARs evaluation, Visual Analog Pain Scale (VAS), and radiographic exams.
• Fracture presence was confirmed by imaging (54% of patients).

Main Results:

• OARs demonstrated 100% sensitivity for both ankle and midfoot injuries.
• OARs specificity was 26% for ankle and 62% for midfoot injuries.
• Adding a VAS score of 5+ significantly increased specificity to 38% (overall) and 47% (ankle), potentially reducing CT scans by 100%.

Conclusions:

• OARs are useful for the studied population, with high sensitivity for fracture detection.
• Integrating pain assessment (VAS) and accident context can improve rule specificity.
• These strategies may reduce unnecessary radiographic examinations and associated costs.