How do you perform an Anterior Drawer Test of the Ankle?
The test is performed with the patient seated at the end of the bed or lying supine with their knee flexed to neutralize the pull of the gastrocnemius – soleus muscles.
With the ankle joint held at 10 to 15° of plantar flexion, the examiner grasps around the heel with one hand and stabilizes the tibia from the anterior side with the other.
After asking the patient to relax the muscles, the examiner pulls the heel forward while continuing to stabilize the tibia with the other hand.
What does a positive Anterior Drawer Test of the ankle mean?
In the presence of a rupture of the anterior talofibular ligament, usually combined with injury to the capsule, the talus, and with it the foot, rotates anteriorly out of the ankle mortise around the intact medial (deltoid) ligament of the ankle, which serves as the center of rotation.
The test suggests talofibular instability as a result of rupture of the anterior talofibular ligament ATFL.
Sensitivity & Specificity
A Prospective, blinded, diagnostic-accuracy study 1 by Theodore Croy to investigate the accuracy of the anterior drawer test of the ankle in patients with lateral ankle sprain, he found that the ankle anterior drawer test provides limited ability to detect excessive anterior talofibular ligament (ATFL) injury, the sensitivity and specificity was as following:
Sensitivity: 74 %
Specificity: 38 %
However, it may provide useful information when used in side-to-side ankle comparisons and in conjunction with other physical exam procedures, such as palpation.
The ATFL can be palpated two to three finger-breadths anteroinferior to the lateral malleolus. This is usually the area of most extreme tenderness following an inversion sprain. The anterior aspect of the distal tibiofibular syndesmosis may also be tender following this type of sprain.
This test has limited reliability, particularly if it is negative or if it is performed without anesthesia in the presence of muscle guarding.
It has been reported that 4 mm of laxity in the ATFL, resulting from posttraumatic attenuation or fibrosis, will give a clinically apparent anterior drawer (2 mm is normal) (false positive findings may be seen in up to 19% of uninjured ankles in those with ligamentous laxity).
In dorsiflexion, the Posterior Talofibular Ligament (PTFL) is maximally stressed, and the Calcaneofibular ligament (CFL) is taut, whereas the ATFL is loose. Conversely, in plantarflexion, the ATFL is taut, and the CFL and PTFL become loose.
The strength of the ankle ligaments from weakest to strongest is the ATFL, PTFL, CFL, and deltoid complex.
Anterior Talofibular Ligament:
This thickening of the anterior capsule extends from the anterior surface of the fibular malleolus, just lateral to the articular cartilage of the lateral malleolus, to just anterior to the lateral facet of the talus and to the lateral surface of the talar neck.
The anterior talofibular ligament (ATFL) is an intracapsular structure and is approximately 2–5-mm thick and 10–12-mm long.
The ATFL functions to resist ankle inversion in plantarflexion. Regardless of ankle position, the ATFL is usually the first ankle ligament to be torn in an inversion injury.
The accessory functions of the ATFL include providing resistance against anterior talar displacement from the mortise and resistance against internal rotation of the talus within the mortise.
The ATFL requires the lowest maximal load to produce failure of the lateral ligaments, although it has the highest strain of failure in that group
Croy T, Koppenhaver S, Saliba S, Hertel J. Anterior talocrural joint laxity: diagnostic accuracy of the anterior drawer test of the ankle. J Orthop Sports Phys Ther. 2013 Dec;43(12):911-9. doi: 10.2519/jospt.2013.4679. Epub 2013 Oct 30. PMID: 24175608.
Clinical Tests for the Musculoskeletal System 3rd Edition.
Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.