Quick and simple test to evaluate severity of acute lateral ankle sprain

Background/objective: For early return to sports after a lateral ankle sprain (LAS) and recurrence prevention, effective rehabilitation and gradual return to sports should be initiated while predicting the return time based on the appropriate severity evaluation immediately after injury. However, since severity evaluations performed in previous studies required large space and stairs and involved high-revel activity, their use as a test and index to evaluate severity after LAS was not appropriate considering convenience and risk of re-injury. Therefore, a quick and simple test was developed to evaluate the severity of acute LAS. This study aimed to verify the association between ankle function for severity evaluation and anterior talofibular ligament (ATFL) injury type by ultrasonography and to clarify the usefulness for acute LAS severity evaluation of the single-leg loading (SLL) test. Methods: In total, 50 patients (34 men, 16 women) out of 58 patients who visited our sports clinic within 3 days after acute LAS and who conformed to the study criteria were included in this study. During the first visit, SLL test and objective/subjective ankle joint evaluation were performed. The SLL test consists of single-leg standing, single-leg heel raising and single-leg hopping, and patients were classified into four levels from 1 to 4 according to results. In addition, ultrasonographic evaluation was performed within 1 week after the first visit to evaluate the type of ATFL injury. Type I was defined as intact ATFL, Type II as swollen ATFL with an almost intact fibrillar pattern and Type III as ATFL appearing swollen with a disrupted fibrillar pattern. The relationship between the SLL test and each evaluation item was investigated using Spearman's correlation coefficient. Results: As a result of the SLL test, 15 patients had Level 1 (30%), 19 Level 2 (38%), 5 Level 3 (10%) and 11 Level 4 (22%). With regard to correlation coefficients of the SLL test, Japanese Society for Surgery of the Foot ankle/hindfoot scale and sports activity were rs = 0.71 (p < 0.001) and rs = 0.66 (p < 0.001), respectively, showing a significant positive correlation. SLL test and the type of ATFL injury also showed a significant negative correlation (rs = −0.58, p < 0.001). Conclusions: The SLL test was a simple and useful test that can be used as an index to evaluate the severity of acute LAS