Sports Medicine Research: In the Lab & In the Field: What’s in the Anterior Drawer? Probably Not Accuracy (Sports Med Res)
Monday, December 16, 2013

What’s in the Anterior Drawer? Probably Not Accuracy

Diagnostic Accuracy of the Anterior Drawer Test for the Ankle

Croy T, Koppenhaver S, Saliba S, Hertel J. J Orthop Sports Phys Ther. 2013 Dec; 43(12):911-9. http://www.ncbi.nlm.nih.gov/pubmed/24175608

Take Home Message: The anterior drawer test for the anterior talocrural joint has a low diagnostic accuracy, and therefore the results of the test alone should be interpreted with caution.  Clinicians may want to consider the use of imaging modalities, such as diagnostic ultrasound, in the evaluation of the anterior talofibular ligament after an ankle sprain.

The anterior drawer test is commonly used to assess the severity of injury to the anterior talocrural joint (e.g., anterior talofibular ligament) after an inversion mechanism at the ankle.  Many physical examination techniques, including the anterior drawer test, have demonstrated low reliability and diagnostic accuracy, which leads researchers and clinicians to interpret results of the anterior drawer test with caution.  While the anterior drawer test has been previously evaluated in existing literature, there have been few reports about its diagnostic capabilities, especially in combination with the extent of joint laxity and the clinical usefulness of the test.  The purpose of this study was to evaluate the diagnostic accuracy of the anterior drawer test, as well as to determine the extent that the anterior drawer test assists clinicians in determining anterior talocrural joint laxity.  In the current study, the authors included 66 participants; each participant was classified as having: an acute lateral ankle sprain (22 participants); a history of one ankle sprain with no remaining symptoms (ankle sprain copers, 19 participants); or a history of recurrent ankle sprains (chronic ankle instability, 25 participants).  To assess the diagnostic accuracy of the anterior drawer test (graded 0 [hypomobile] to 4 [severe laxity]), the authors manually applied a standardized anterior drawer force using an arthrometer while visualizing landmarks on the talus and fibula with diagnostic ultrasound.  The authors investigated the diagnostic performance of the anterior drawer test compared with two cutoff values for abnormal laxity (2.3 mm and 3.7 mm; based on healthy controls and previous research).  The authors demonstrated that participants with a history of a lateral ankle sprain had greater anterior talocrural joint laxity (~3.4 mm) compared with healthy participants (~0.2 mm). Only one healthy control was considered to have abnormal laxity (using either cutoff).  In contrast, 53% or 36% of participants with a history of an ankle sprain had abnormal laxity at the anterior talocrural joint based on the cutoff of 2.7 mm or 3.7 mm; respectively.  Sensitivity of the anterior drawer test compared with the 2.3 mm cutoff was ~0.74 and specificity was ~0.38 (see definitions below).  The positive and negative likelihood ratios were 1.2 and 0.66, respectively at the 2.3 mm reference.  When the authors used the larger laxity cutoff of 3.7 mm, the sensitivity and specificity of the anterior drawer test were ~0.83 and ~0.40, respectively, with a positive likelihood ratio of 1.4 and a negative likelihood ratio of 0.41.  Likelihood ratios of these magnitudes are considered small, which raises concerns about the diagnostic performance of the anterior drawer test.

Overall, this study reported that the anterior drawer test demonstrated low diagnostic accuracy compared with two reference standards.  A positive anterior drawer test may lead to small and unimportant changes in the likelihood of identifying abnormal talocrural joint laxity, and a negative anterior drawer test may cause small changes in the likelihood that the patient or participant will not demonstrate abnormal talocrural joint laxity.  Evaluated by an experienced clinician, nearly 70% of the participants in this study were classified as having a positive anterior drawer test.  According to the results, between 42% and 56% of these participants would be considered to have a false positive test result, which the authors attribute to the clinician technique and patient position utilized during the anterior drawer test.  When using the anterior drawer test to assess the integrity of the anterior talofibular ligament, clinicians should continue to interpret subjective results with caution.  Because the anterior drawer test appears to be a poor predictor of talocrural joint laxity, the authors suggest that if sophisticated measurement techniques such as diagnostic ultrasound or stress radiographs are available, clinicians should consider these techniques as more accurate alternatives. 

Questions for Discussion: Would you consider modifying your physical exam techniques based on the results of this study?  Do you have training and/or access to diagnostic ultrasound in your primary setting?  How important is accurate assessment of laxity in the overall treatment plan your patients?

Written by: Kimberly Pritchard
Reviewed by: Jeffrey Driban

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Related Posts:

Croy T, Koppenhaver S, Saliba S, & Hertel J (2013). Anterior talocrural joint laxity: diagnostic accuracy of the anterior drawer test of the ankle. The Journal of Orthopaedic and Sports Physical Therapy, 43 (12), 911-9 PMID: 24175608

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