Ankle ultrasound for detecting anterior talofibular ligament tear using operative finding as reference standard: a systematic review and meta-analysis

Purpose: To evaluate the diagnostic accuracy of ankle ultrasound for detection of anterior talofibular ligament (ATFL) tear with a reference standard of operative finding. Methods: A computerized search of PubMed and EMBASE databases was performed to identify relevant original articles on ankle ultrasound for ATFL tear. The pooled proportions of the diagnostic accuracy estimates were assessed using random-effects modeling. We also assessed pooled proportions of the diagnostic accuracy according to injury stage (acute or chronic) and severity of injury (complete or partial). Heterogeneity among studies was determined using the inconsistency index (I²). Meta-regression analyses were performed to evaluate the potential sources of heterogeneity. Results: Ten studies were included. The pooled proportion of the diagnostic accuracy of ankle ultrasound for ATFL was 0.95 (95% confidence interval [CI] 0.88–0.98). In subgroup analysis, the pooled proportion of the diagnostic accuracy of ankle ultrasound for acute ATFL tear was 0.92 (95% CI 0.85–0.95). The pooled proportion of the diagnostic accuracy of ankle ultrasound for chronic ATFL tear was 0.96 (95% CI 0.84–0.99). The pooled proportions of the diagnostic accuracy for complete and partial ATFL tear were 0.82 (95% CI 0.72–0.89) and 0.88 (95% CI 0.70–0.96), respectively. In the meta-regression analyses, the inclusion of pediatric patients was only significantly different (p = 0.007). Conclusions: Ankle ultrasound may be a useful diagnostic modality in the detection of ATFL tear in adults and children, regardless of injury stage and severity. For correct diagnosis of ATFL tear, a high-frequency ultrasound probe and sufficient experience of the examiner are mandatory.