The Ottawa Ankle and Knee Rules help healthcare providers determine if an X-ray is necessary following an injury to the ankle or knee. These guidelines are used to identify fractures, guiding whether an X-ray is needed before starting physiotherapy or other treatments.

For the ankle:

An X-ray is recommended if there is pain in the malleolar zone (medial or lateral) and any of the following:

• Bone tenderness at the posterior edge or tip of the lateral malleolus
• Bone tenderness at the posterior edge or tip of the medial malleolus
• An inability to bear weight immediately and in the emergency department (or physician’s office) for four steps.

For the knee:

An X-ray is recommended if there is any of the following:

• Age 55 years or older
• An inability to flex the knee to 90 degrees
• Isolated tenderness of the patella (kneecap)
• Tenderness at the head of the fibula
• An inability to bear weight immediately and in the emergency department (or physician’s office) for four steps.

If any of these criteria are met, it’s advisable to undergo an X-ray to rule out any fractures before starting physiotherapy or other treatments. Always consult with a healthcare professional for a proper assessment and guidance regarding injuries.