The double fascicular variations of the anterior talofibular ligament and the calcaneofibular ligament correlate with interconnections between lateral ankle structures revealed on magnetic resonance imaging

Abstract

The anterior talofibular ligament and the calcaneofibular ligament are the most commonly injured ankle ligaments. This study aimed to investigate if the double fascicular anterior talofibular ligament and the calcaneofibular ligament are associated with the presence of interconnections between those two ligaments and connections with non-ligamentous structures. A retrospective re-evaluation of 198 magnetic resonance imaging examinations of the ankle joint was conducted. The correlation between the double fascicular anterior talofibular ligament and calcaneofibular ligament and connections with the superior peroneal retinaculum, the peroneal tendon sheath, the tibiofibular ligaments, and the inferior extensor retinaculum was studied. The relationships between the anterior talofibular ligament’s and the calcaneofibular ligament’s diameters with the presence of connections were investigated. Most of the connections were visible in a group of double fascicular ligaments. Most often, one was between the anterior talofibular ligament and calcaneofibular ligament (74.7%). Statistically significant differences between groups of single and double fascicular ligaments were visible in groups of connections between the anterior talofibular ligament and the peroneal tendon sheath (p < 0.001) as well as the calcaneofibular ligament and the posterior tibiofibular ligament (p < 0.05), superior peroneal retinaculum (p < 0.001), and peroneal tendon sheath (p < 0.001). Differences between the thickness of the anterior talofibular ligament and the calcaneofibular ligament (p < 0.001), the diameter of the fibular insertion of the anterior talofibular ligament (p < 0.001), the diameter of calcaneal attachment of the calcaneofibular ligament (p < 0.05), and tibiocalcaneal angle (p < 0.01) were statistically significant. The presence of the double fascicular anterior talofibular ligament and the calcaneofibular ligament fascicles correlate with connections to adjacent structures.

Anatomical variations and interconnections of the superior peroneal retinaculum to adjacent lateral ankle structures: a preliminary imaging anatomy study

“…The IER, due to its location, was found to serve as an intermediate station for connecting the SPR to the ATFL. These imaging studies confirm previous findings regarding lateral ankle ligament interconnections reported in cadaveric studies ( 18 , 21 ) and MRI ( 11 ) . The SPR connection to the calcaneofibular ligament and the Achilles paratenon was reported previously both in cadavers and MR imaging studies ( 12 , 21 ) .…”

“…SPR connections are essential components of a functional complex at the lateral malleolus level ( 12 , 27 ) . Statistically significant differences in the occurrence of connections revealed on MRI between the ATFL and PTS were noticed before between groups of single and double fascicular ATFL and CFL ( 11 ) . It is challenging to distinguish between single and double fascicular ATFL on US; thus, comparing the results is not entirely possible, which is a limitation of this study.…”

“…There is no sufficient anatomical background for the cited clinical observation. The presence of a concomitant injury of the lateral ankle ligament results from the mechanism of injury and is probably related to interconnections between ligaments ( 10 , 11 ) . Connections of the SPR with ligaments in the Kager’s fat pad were previously revealed ( 12 ) .…”

“…Various MR studies have evaluated the appearance of the SPR and variations of the peroneal tendon complex ( 1 , 5 , 14 – 17 ) . Using MR imaging, interconnections have been reported between the following structures: the anterior talofibular ligament (ATFL), the inferior extensor retinaculum (IER), and the peroneal tendon sheath (PTS), and their association to other common anatomical variations described in the literature ( 11 , 12 , 18 , 19 ) . Interconnections of the SPR to the lateral ankle structures have not been previously reported on US, and limited literature is available using MR ( 12 ) .…”

The Location of the Fibular Tunnel for Anatomically Accurate Reconstruction of the Lateral Ankle Ligament: A Cadaveric Study

“…The fibular origins of ATFL and CFL are concentrated in the lower part of the lateral malleolus and connected with connective fiber [ 18 ]. Also, ligament injury is likely to occur at the fibular side or substantial part of the ligament [ 4 , 6 ].…”