Anatomical dissection of the calcaneofibular ligament of the ankle – a macroscopic and morphometric study

Introduction and objective. Common to the talocrural and subtalar joints, the calcaneofibular ligament forms with the anterior bundle a mechanical coupling factor for ankle stabilization. Adhering to the deep surface of the fibular sheath, doubled in depth by the lateral talocalcaneal ligament, it is solicited in isolated varus and its lesion is involved in subtalar instability. The therapeutic strategy for chronic ankle instability is currently based on the anatomical reconstruction of the ligaments, particularly by arthroscopy, hence the objective of this study, which aims to highlight the great variability of the calcaneofibular ligament. Materials and method. Our work is based on the dissection of 24 ankles. The number of beams, the dimensions at the neutral point and after power-up, the relationships with the surrounding anatomical structures as well as the points of insertion of the CFL are studied. Results. The calcaneofibular ligament was monofascicular in 91.6% of cases and bifascicular in 8.4%. Its average length in a neutral position was 26.85 ± 3.46 mm, and its width was 5.33 ± 1.45 mm. In dorsiflexion, the length was 27.10 ± 0.05 mm, and in forced inversion, it was 26.98 ± 0.07 mm. The distance between its fibular insertion and the apex of the lateral malleolus was 6.2 ± 0.9 mm. Conclusions. Injuries of the calcaneofibular ligament are common in lateral ankle sprains, which can often get complicated by chronic instability. The macroscopic and morphometric knowledge of this ligament can allow a more accurate anatomical reconstruction and a more accurate choice of graft.