Anterior drawer test for acute anterior talofibular ligament injuries of the ankle. How much load should be applied during the test?

BACKGROUND There is a lack of consensus regarding the magnitude of load for performing the anterior drawer test in evaluating acute ankle injuries. PURPOSE To determine how much load should be applied during the anterior drawer test to detect the integrity of the anterior talofibular ligament. METHODS First, the anterior-posterior load-displacement response of nine cadaveric ankles was measured. Second, anterior displacement of the ankle was measured at 30 and 60 N of anterior load in 14 patients with acute tears of the anterior talofibular ligament. RESULTS In the cadaver study, the increased displacement by sectioning of the ligament measured at 10, 20, 30, and 40 N of anterior load were significantly greater than those measured at 60 N. In vivo examination of the subjects without anesthesia demonstrated that the injured-to-normal displacement value at 30 N of anterior load was significantly greater than the value at 60 N. CONCLUSIONS This study suggests that a large magnitude of anterior load is not necessary to detect the integrity of the ligament during the anterior drawer test. CLINICAL RELEVANCE When evaluating the integrity of the anterior talofibular ligament in cases of acute ankle ligament injury, a relatively low-magnitude load should be applied.