Diagnostic Accuracy of Clinical Tests for Ankle Syndesmosis Injury
Sman AD, Hiller CE, Rae K, Linklater J, Black DB, Nicholson LL, Burns J, & Refshauge K. British Journal of Sports Medicine. Published Online First November 19, 2013 doi:10.1136/bjsports-2013-092787
Take Home Message: There is no one perfect test for high ankle sprain evaluation. However, there are a few things that you can assess to help rule in or out the diagnosis.
High ankle sprain injuries can be difficult to differentiate from a lateral ankle sprain or an anterior tibialis strain when a person suffers an ankle injury; however, it is important to identify a high ankle sprain early to appropriately manage. If we could identify a battery of accurate special tests for diagnosing high ankle sprains (like the Ottawa ankle rules for fractures), this may help clinicians improve our patients’ outcomes. The authors compared commonly-used assessments to diagnose high ankle sprains (e.g., syndesmotic point tenderness, dorsiflexion with external rotation test, dorsiflexion lunge test with compression, the squeeze test) with magnetic resonance imaging (MRI) - the gold standard for diagnosis. Thirteen clinicians evaluated a total of 87 participants (78% male, average age 25 years) who had an acute ankle injury and an MRI within 2 weeks of the injury. Thirty-eight participants had a high ankle sprain based on MRI. The clinicians assessed the patients with the 4 previously mentioned clinical diagnostic tests and 7 clinical presentations (e.g., pain/dysfunction out of proportion to the injury, pain felt in the leg and/or knee, single leg hop test). Diagnostic accuracy of the 4 clinical diagnostic tests ranged from 53.7 (dorsiflexion with compression) to 66.7% (dorsiflexion with external rotation). Sensitivity (ability to yield positive test result in a group that has the condition) ranged from 26 to 92% with the highest values being with syndesmotic point tenderness (92%) and the dorsiflexion with external rotation test (71%). Specificity (ability to yield negative test result in a group that does not have the condition) ranged from 29 to 88% with the highest values being found with the squeeze test (88%) and the dorsiflexion with external rotation test (63%). Diagnostic accuracy values were also calculated on a variety of clinical presentation symptoms, with the highest sensitivity being found for inability to perform a single leg hop, inability to walk (both 89%) and mechanism of injury (83%). The authors found that highest specificity with pain out of proportion (79%) and pain felt in lower leg or knee during injury (70%).
Clinicians should not rely on a single test to diagnose high ankle sprains, but can use this information to help determine which tests may be best in interpreting a clinical case. The authors suggested that clinicians should combine some sensitive and specific assessments when we evaluate the ankle: 1) inability to hop, 2) inability to walk, 3) tenderness of the syndesmosis ligament, 3) dorsiﬂexion-external rotation stress test, 4) pain out of proportion to the apparent injury, and 5) the squeeze test. Unfortunately, these five assessments may not always lead to the same result, which means that clinicians need to use their experience to make the final decision. Hopefully clinicians can use this information to more accurately diagnose and appropriately treat high ankle sprains. Oftentimes, lingering pain is a result of an undiagnosed high ankle sprain. As clinicians, we need to conduct a thorough clinical examination, and be informed as to the value of certain findings for ruling things in or out.
Questions for Discussion: Are there any other tests that you think may be valuable in evaluating high ankle sprains? Are there any other clinical presentations that you have found to be helpful in diagnosing high ankle sprains?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban