OBJECTIVES: The aim of our study was to compare the identified morphological and dynamic sonography differences between the results of ultrasonic examinations of children with lateral ankle injuries and the functional scores at given times after the injury of the American Orthopaedic Foot and Ankle Society (AOFAS) and Foot and Ankle Disability Index (FADI).

METHODS: The study was carried out at Sándor Péterfy street Hospital and Casualty Centre in Budapest, Hungary from January 2017 to November 2017. We included children under 16 years (n=50), with external ankle ligament injury where the examining physician found divergence with ultrasound imaging but no disorder with X-ray imaging. The patients were further examined during the 4^th to 8^th weeks and the 12^th weeks after the injury. After the examinations, the sonographic findings and functional scores were analyzed and compared by the physiotherapist.

RESULTS: Throughout the 12 weeks of the study, our analysis showed a significant difference (p=0.000) in all of the reported scores’ averages compared to the 100 points (full function) in the case of thickening of ligament, avulsion fracture, abnormal opening, ruptured ligament. For the group who had normal ligament from the beginning, on the 4^th week there was a significant difference (p=0.033, Avg=95.50), no significance could be observed in the 8^th week (p=0.102, Avg=99.33), and in the 12^th week, when everyone achieved 100 points.

CONCLUSIONS: The ultrasound image showed morphological changes which correlated with the functional scores of the children. In our view, it is possible to use high-frequency ultrasound imaging to influence the adverse reaction free function.