Posterior Talofibular Ligament: The Relationship between its Length and Talar Morphometric Profiles

CATEGORY: Ankle, Sports INTRODUCTION/PURPOSE: Posterior talofibular ligament is one of the lateral ligamentous complex of the ankle. However, little is known about its anatomic profile especially on the relationship between its length and the morphometric profiles of talus. The present was to analyze the correlations between PTFL length and the talar morphometric profiles in the cadaveric specimens. The PTFL variation was also reported in this study. METHODS: A total of twenty four cadaveric ankles as twelve matched pairs of ankle were collected in this study. All ankles were measured with a Vernier caliper which provided the data for further analysis regarding the PTFL length and the talar morphometric profiles. The data was calculated to demonstrate the relationship between PTFL length and the morphometric profiles of talus. There was a cadaveric ankle which was not used in the study due to its absence of PTFL. RESULTS: An average length of PTFL was 23.9+/-6.9 mm. In overall, an average talar length (TaL) was 53.5 millimeters (mm). An average talar dome height (TaH) was 31.2 mm. An average talar body width (TaW) was 41.3 mm. The average anterior trochlear width (TrAW), middle trochlear width (TrMW), posterior trochlear width (TrPW), and trochlear length (TrL) were 31.8, 31.2, 28.3, and 30.7 mm. Based on twenty three ankles, the paired samples T-test showed the significantly negative correlations between PTFL length and TrL (Pearson’s r correlation coefficient: -0.432; P-value: 0.039). Other correlations were in negative values but P-values > 0.05. There were 16 ankles (84.2%) with 1 PTFL band and 3 ankles (15.8%) with 2 bands from 19 ankles with complete data. CONCLUSION: The present study may be a first study which delineates the relationship between PTFL length and the morphometric profiles of talus. The PTFL length was negatively correlated with talar size especially on the trochlear length of talus.