Bauer et al developed a decision rule for identifying patients needing X-rays of the knee after an acute injury. The study was done in Stony Brook at SUNY.


Patients with fractures were found more likely to have:

(1) severe joint line tenderness

(2) severe localized swelling

(3) an effusion

(4) ecchymosis

(5) flexion limited to < 90°

(6) inability to bear weight


Decision Rule for ordering radiographs: Radiographs done only if one or more of the following are present:

(1) inability to bear weight

(2) an effusion is present

(3) ecchymosis is present


Performance of rule:

• Bauer et al found the rule 100% sensitive for fracture

• Use of the rule allowed a 39% reduction in number of radiographs ordered without missing a fracture.


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