Treatment of stage 4 adult acquired flatfoot.

Stage 4 PTT dysfunction is a rare anatomic condition in which fixed hindfoot valgus is associated with valgus tilting of the talus within the ankle mortise. Success with nonoperative management is the exception rather than the rule. The surgical options are a tibiotalocalcaneal fusion or a pantalar fusion; however, there are few results reported in the adult acquired flatfoot population. Valgus talar tilting after triple arthrodesis may be the challenge of the future.