The posterior talofibular ligament: an anatomical study with clinical implication in clubfoot surgery

The role of the posterior talofibular ligament (PTFL) in the clubfoot deformity remains unclear. We conducted an anatomical study to precise its topography and role in maintaining tibiotalar equinus in patients with clubfoot deformity.

Ten ankles were dissected using a wide posterior exposure. The PTFL was identified at the posterior aspect of the ankle and its relations with other anatomical structures were noted.

After opening of the tibiotalar and subtalar joints, the superior aspect of the PTFL was clearly seen, running horizontally from the fibula to a prominent tubercle on the posterior surface of the talus. The tibiotalar and subatalar joint capsules joined together laterally on the posterior edge of the PTFL and medially on the posterior part of the talus. A fibrous structure identified as being the "tibial slip" was noted in four cases between the posterior medial aspect of the lateral malleolus and the tibiotalar posterior capsule. Two different groups of fibers were identified inside the PTFL.

Correcting the equinus and inversion of the talus needed an extensive release of soft tissues of the posterior part of the ankle. Our description of both short anterior and long posterior fibers of the PTFL improved our comprehension of functional anatomy of this ligament. We have found that PTFL is part of a posterior joint complex between the tibiotalar and subtalar joint. The posterior joint complex is a heritage of ankle evolution from a prehensile to a weight-bearing joint pattern. The inferior tibiofibular transverse ligament, the tibial slip and the calcaneofibular ligament are interpreted as derivatives of this ancestral meniscus and stabilize the weight-bearing ankle. Because the posterior fibers of the PTFL and the tibial slip are part of the complex, they should be excised like the posterior capsules during clubfoot surgery.