Sensitivity and specificity of ultrasound in the diagnosis of traumatic ankle injury

Abstract

Background: This study was performed to determine the sensitivity and specificity of ultrasound in the diagnosis of traumatic ankle injury in comparison with magnetic resonance imaging (MRI). Materials and Methods: This cross-sectional study was performed on 31 patients with soft-tissue injury or fracture, referring to the MRI imaging center of Alzahra and Kashani Hospitals in Isfahan from October 2018 to March 2019. After an MRI, an ultrasound of the affected ankle was performed for all patients. Sonography and MRI were performed by two radiologists who were blinded to the results of each other's reports. The sensitivity, specificity, positive predictive value, and negative predictive value of sonography were determined. Results: In this study, 31 patients with ankle trauma were studied. The mean age of the patients was 30.73 ± 10.15 years; 32.3% were male and 67.7% were female. The sensitivity of ultrasound relative to MRI to detect damage to the anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), and calcaneofibular ligament (CFL) was 66.67%, 50%, and 100%, respectively, and the corresponding specificity was 92.86%, 93.10%, and 93.10%, respectively. According to Kappa test, the agreement between ultrasound and MRI methods for detecting injury to ATFL (κ = 0.51), PTFL (κ = 0.35), and CFL (κ= 0.63) was statistically significant (P < 0.05). Conclusion: Ultrasound is an appropriate modality for the diagnosis of injuries to CFL and ATFL and has shown acceptable results for PTFL. It could be used as an alternative in cases where access to MRI is not available.

Keywords

• ankle
• diagnosis accuracy
• magnetic resonance imaging
• trauma
• ultrasound