Assessing Lateral Ankle Sprains With a New Arthrometer.

Background: Lateral ankle sprains are a common musculoskeletal injury across a variety of activities. Researchers have sought to identify a method to objectively assess joint laxity with a device that is simple to use and affordable.

Aim: The purpose of this study was to assess the use of an ankle arthrometer on individuals with ankle sprains.

Methods: The participant was evaluated by the physician and the degree of ankle sprain was identified. In the prone position, the arthrometer was used to perform an anterior drawer test (uninjured before injured, 3 measures each). Both clinicians were blinded to the data of the other.

Results: There were 30 participants, 10 in each group (uninjured, grade 1 sprain, grade 2 sprain). Mann-Whitney U testing found significant differences between the control and grade I ankle sprain groups (P < .001), the control and grade II ankle sprain groups (P < .001), and the grade I and grade II ankle sprain groups (P = .004). There was ±0.31-mm difference in anterior translation between healthy ankles, whereas there was 1.11- and 2.16-mm difference between ankles in grade 1 and grade 2 sprains, respectively.

Clinical application: Despite the manual anterior drawer test being convenient, the subjectivity makes it unreliable. This study is consistent with prior literature about the difference in translation (millimeters) between the uninjured and injured ankles corresponding to the magnitude of ankle laxity. This study also contributes to the evolving evidence to support the relationship of a ratio of measures (injured/uninjured) as an objective measure of laxity. These comparisons to the individual's healthy ankle mitigate the variability of the normative values. The use of an arthrometer to assess ankle joint laxity enhances the objectivity of patient assessment throughout the recovery process.

Levels of evidence: Level III.