A new classification of anterior talofibular ligament injuries based on ultrasonography findings

Ultrasonography (US) has become a useful tool in the evaluation of thickness and continuity of damaged ligaments owing to the rapid advances in its performance and availability. Furthermore, US examination is economical and can be undertaken in a more timely manner than MRI, as it can be performed during the first patient visit. It is also likely to be more accurate than the traditional method of palpating ligaments to diagnose possible injury. The anterior talofibular ligament (ATFL) is most frequently injured of the lateral ankle ligaments and easy to depict on US. This study aimed to assess the treatment outcomes of lateral ankle ligament injuries using a new classification for ATFL injuries based on US findings. A total of 140 acute lateral ankle ligament injuries in 132 patients (46 men, 86 women) treated non-operatively were evaluated retrospectively. The average age of the patients was 17.8 years (range, 7–57 years). Patients with a complaint of lateral ankle injury were examined using US, and the anterior talofibular ligament damage was classified into 5 types depending on the type of the injury. The treatment method was selected based on the ultrasonographic classification, and the clinical results were assessed by original evaluation and compared between treatment methods and classification types. A Good or Excellent treatment result was obtained in 133 out of 140 injuries (95.0%). Significant differences were observed in the distribution of treatment methods by injury type (P < 0.001), and the distribution of outcomes was significantly different from the uniform distribution (P < 0.001). Our findings demonstrate that the ultrasonographic classification proposed in this study can be used to determine the appropriate treatment resulting in good outcomes for all types of anterior talofibular ligament damage. Visualization of injured ligaments using US may introduce a novel approach of rating and treating ligament injuries.