Which criterion is NOT part of the Ottawa Knee Rule for obtaining knee radiographs after an acute injury?

Which criterion is NOT part of the Ottawa Knee Rule for obtaining knee radiographs after an acute injury?

• A. Age 55 or older.
• B. Isolated tenderness at the patella.
• C. Inability to bear weight for four steps.
• D. Painful knee flexion to 180 degrees.

Answer: (D)

The test is about a clinical decision rule that helps decide when knee X-rays are needed after an acute injury. The Ottawa Knee Rule uses five features: being 55 years or older; isolated tenderness at the patella; tenderness at the fibular head; inability to bend the knee to 90 degrees; and inability to bear weight for four steps immediately and in the emergency department. These criteria are chosen because their presence raises enough suspicion of fracture to justify imaging, while their absence makes fracture unlikely and radiographs unnecessary. The option describing painful knee flexion to 180 degrees isn’t part of the rule. The rule relies on an inability to flex to 90 degrees as a threshold, not pain or limitation at full flexion. In other words, whether a patient can’t reach 90 degrees or can bear weight four steps is what guides imaging decisions, whereas full-range flexion up to 180 degrees isn’t part of the decision criteria. The other features listed match the Ottawa criteria and support deciding to obtain radiographs if any are present.

The test is about a clinical decision rule that helps decide when knee X-rays are needed after an acute injury. The Ottawa Knee Rule uses five features: being 55 years or older; isolated tenderness at the patella; tenderness at the fibular head; inability to bend the knee to 90 degrees; and inability to bear weight for four steps immediately and in the emergency department. These criteria are chosen because their presence raises enough suspicion of fracture to justify imaging, while their absence makes fracture unlikely and radiographs unnecessary.

The option describing painful knee flexion to 180 degrees isn’t part of the rule. The rule relies on an inability to flex to 90 degrees as a threshold, not pain or limitation at full flexion. In other words, whether a patient can’t reach 90 degrees or can bear weight four steps is what guides imaging decisions, whereas full-range flexion up to 180 degrees isn’t part of the decision criteria. The other features listed match the Ottawa criteria and support deciding to obtain radiographs if any are present.