This study was conducted to measured talar displacement using ultrasound during an anterior drawer test (ADT) with a Telos device. Five adults (3 men and 2 women; 8 ankles; mean age: 23.2 y) with a history of ankle sprain and eight adults (5 men and 3 women; 16 ankles; mean age: 22.1 y) without a history of ankle sprain were recruited into a history of ankle sprain (HAS) and a control group, respectively. Talar displacement was observed in response to load forces applied by a Telos device during the ultrasound stress imaging test. The ultrasound probe was placed 5 mm inside from the center of the Achilles tendon on the posterior ankle along the direction of the major axis. The inter-rater reliability for the present method was classified as good and excellent (ICC(2,2) = 0.858 and 0.957 at 120 N and 150 N, respectively) in the control group and excellent (ICC(2,2) = 0.940 and 0.905 at 120 N and 150 N, respectively) in the HAS group, according to specific intraclass correlation coefficient values. We found that talar displacement during the ADT was lower in the HAS group than in the control group. Analysis of the receiver operating characteristic curve revealed that the quantitative ultrasound-based ADT using a Telos device was superior to the X-ray-based test in detecting reduced ankle joint mobility during the ADT (area under the curve of 0.905 and 0.726 at a force of 150 N using ultrasound-based and X-ray-based tests, respectively). Further investigation is needed; nevertheless, this preliminary study suggests that the ultrasound-based quantitative ADT using a Telos device might detect talar displacement more sensitively than the conventional stress X-ray.
Keywords: ankle flexibility; ankle sprain; anterior drawer test; talus; tibia; ultrasound.