Radiographic Evaluation of the Ankle – The External Rotation Stress Test

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External Rotation Stress Test: The Physician and Sportsmedicine: Vol 30, No 8


Selina Shah, MD
Kelly Richter, MD
Kurt Spindler, MD
Vanderbilt University Sports Medicine Center
Nashville, TN


The ankle is the most commonly injured joint among athletes. Because the treatment course of an ankle injury changes based on whether a fracture has occurred or not, radiographs are often obtained. However, only 15% of these studies are positive for ankle fractures.   The Ottawa criteria for obtaining radiographs have reduced foot and ankle radiographs by 14% and 28%, respectively. The Buffalo rule modification further increases the specificity for accurately ordering radiographic evaluation of a potentially fractured ankle. Additional physical exam and history findings have also been studied and shown to be valuable predictors of significant fracture or syndesmosis injuries. In a study conducted by Drs. Stricker, Spindler, and Gautier, they found that midline distal fibular pain and syndesmosis pain with external rotation showed a significant association with ankle mortise injury thus necessitating radiographic evaluation. Swelling and ecchymosis were not significantly associated with severity of injury because these findings are nonspecific and can appear with ligament tears and avulsions and injuries to small blood vessels. Using the external rotation stress test by experienced sports medicine physicians was shown to be 100% sensitive AND 68% specific, which would reduce radiographic evaluation by 55%. The external rotation stress test is performed by stabilizing the lower leg with one had and applying an external rotation force to the ankle with the other hand. A positive test will elicit pain. (“Prospective Evaluation of History and Physcial Examination: Variables to Determine Radiography in Acute Ankle Injuries,” Clinical Journal of Sports Medicine. 1998;8(3):209-214.)