Intra- and interrater measurement reliability of lateral ankle ligament attachment locations using three-dimensional magnetic resonance imaging

Background: We aimed to evaluate the intra- and interrater measurement reliability of the lateral ankle ligament attachment locations using three-dimensional magnetic resonance imaging. Methods: We analysed 54 participants with a mean age of 43 years who underwent three-dimensional ankle magnetic resonance imaging and had normal lateral ligaments. Bony landmarks of the distal fibula, talus, and calcaneus were identified in the reconstructed images. The centers of the anterior talofibular ligament and calcaneofibular ligament attachments were also identified. The distances between the landmarks and attachments were measured. Two raters performed the measurements twice, and intra- and interrater intraclass correlation coefficients were calculated. Results: The intrarater intraclass correlation coefficient values were between 0.71 and 0.96 for the anterior talofibular ligament attachment measurements and between 0.77 and 0.95 for the calcaneofibular ligament attachments. The interrater intraclass correlation coefficient was higher than 0.7, except for the distance between the anterior talofibular ligament superior bundle and fibular obscure tubercle. The fibular attachment of a single-bundle anterior talofibular ligament was located 13.3 mm from the inferior tip and 43% along the anterior edge of the distal fibula. The superior and inferior bundles of the double-bundle ligament were located at 43% and 23%, respectively. The calcaneofibular ligament fibular attachment was 5.5 mm from the inferior tip, at 16% along the anterior edge of the distal fibula. Conclusion: The measurements of anterior talofibular ligament and calcaneofibular ligament attachment locations identified on three-dimensional magnetic resonance imaging were sufficiently reliable. This measurement method provides in vivo anatomical data on the lateral ankle ligament anatomy.