Most people are familiar with the Ottawa Ankle Rules, but there are also Ottawa Knee and Foot rules. The Ottawa rules help to limit the number of x-rays you may need in patients that present with ankle, foot or knee pain after an injury.
The Ottawa Ankle Rule
An ankle x-ray is only needed if there pain in the mallelolar area and any of the following:
- Bone tenderness at the posterior tip of the base of the lateral mallelous
- Bone tenderness at the posterior tip of the base of the medial mallelous
- Inability to weight bear immediately and in the Emergency Department
The Ottawa Foot Rule
A foot x-ray is only needed if there is pain in the midfoot and any of the following:
- Bone tenderness at the base of the 5th metatarsal
- Bone tenderness over the navicular
- Inability to weight bear immediately and in the Emergency Department
The Ottawa Knee Rule
A knee x-ray is only needed for knee injury patients when they have any of the following:
- Age 55 or over
- Isolated tenderness of the patella (no bone tenderness of the knee other than the patella)
- Tenderness at the head of the fibula
- Inability to flex to 90 degrees
- Inability to weight bear both immediately and in the Emergency Department (4 steps - unable to transfer weight twice onto each lower limb regardless of limping).