Progressive collapse of an adult foot - a new opinion on an old topic

Introduction: the problem of defi tion and classifi ation system of flatfoot is widely discussed in modern literature. Most often, the term “AAFD” - Adult Acquired Flatfoot Deformity - can be found. Acquired flatfoot in adults is multicomponent and includes disorders such as tibialis posterior tendon dysfunction, tibialis posterior tendon rupture, peritalar foot instability and peritalar foot subluxation, as well as progressive planovalgus or equinoplanovalgus foot deformity. In view of this “versatility” of flatfoot, there is a need to identify the primary element in the pathogenesis of the disease and to create a classifi ation that takes into account the progressive nature of the deformity. It is widely believed that dysfunction of the tibialis posterior tendon is the primary element in the pathogenesis of flatfoot. Of course, all of the described components of pes planus are associated with dysfunction of the tibialis posterior tendon. However, the question of the primacy of tendon dysfunction is currently debatable, since there are descriptions of primary deformation of the midfoot or ankle joint in acquired flatfoot in adults. One of the most common and frequently used classifi ations for assessing acquired flatfoot in adults is the classifi ation presented by Johnson and Strom (1989), which was then modifi d by Myerson (1997). It is based specifi ally on dysfunction of the posterior tibial tendon, without considering the other components of the deformity. Many attempts have been made to create a more correct and complete classifi ation system that would include all components of acquired flatfoot in adults. However, despite the fact that the new classifi ation systems took into account the anatomical variability of the deformity, none of them was able to put an end to the issue of the primary element in the pathogenesis of acquired flatfoot.