Ottawa Ankle and Knee Rules Ankle Rules Knee Rules Ankle Injury Assessment Malleolar Pain Pain in posterior edge or tip of lateral/medial malleolus Weight Bearing Inability to bear weight immediately AND in ED Midfoot Pain Pain in navicular or base of 5th metatarsal Knee Injury Assessment Age ≥ 55 Patient under 55 years old? Isolated Patellar Pain No other bony tenderness? Knee Flexion ≥ 90° Able to flex knee to 90 degrees? Weight Bearing Able to bear weight immediately AND in ED? Assess Imaging Need Clinical Guidelines Sensitivity: 98-100% for ankle fractures Specificity: 30-50% (reduces unnecessary X-rays by 30-40%) Validation: RCT validated in emergency settings