LAUSR

This article introduces novel types of ankle arthritis related to a flatfoot deformity. There has been a long-held belief that severe unmanaged flatfoot deformity leads to valgus ankle arthritis, due to deltoid ligament insufficiency. However, flatfoot deformity can also give rise to varus ankle arthritis as the talus and calcaneus subluxate into opposite directions. Plantarflexion and posterior translation of the talus in the sagittal plane contributes to the eccentric narrowing of the posterior aspect of the tibiotalar joint, which the authors termed posterior ankle arthritis. Subtalar arthrodesis was performed to address the opposing dynamics of the talus and calcaneus, and was combined with a medial longitudinal arch reconstruction in most cases of posterior ankle arthritis and in selected cases of varus ankle arthritis, and satisfactory clinical and radiological results were achieved.