X-rays required only for patients with knee injury who have the following: age 55 years or older, tenderness in the fibula head, isolated tenderness of the patella, inability to flex to 90′, and inability to bear weight immediately and in the emergency department.
Applying these rules results in a 28% reduction in the number of radiographs.
100% sensitive for identifying fractures of the knee and its use can reduce the use of radiography.
Applied to children over the age of 5 years has a 100% sensitivity.