Ottawa Knee Rules are a clinical decision rule used after an acute knee injury to help decide whether a knee X-ray is needed to look for a fracture. In general, a knee X-ray is recommended if any of these are present: age ≥55, isolated patellar tenderness, fibular head tenderness, cannot flex to 90°, or cannot bear weight for 4 steps both immediately and at assessment. acsearch.acr.org+3NICE+3Clinical Knowledge Summaries+3
