Adult-Acquired Flatfoot Deformity

Progressive Collapsing Foot Deformity (PCFD) is a term recently introduced by a consensus group to describe and classify adult flatfoot deformity. This recognizes the disorder as a three-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction and midfoot varus, with the progressive and collapsing nature and enables the treatment of each segment of the foot and ankle as either flexible or rigid. PCFD is a chronic condition starting from the medial aspect of the foot and ankle with dysfunction of the posterior tibial tendon (PPT), the spring and deltoid ligaments, and shifting to the lateral aspect of the foot gradually. Treatments start with orthotic arch supports and braces and are followed by surgery if the above methods fail. Common surgeries include osteotomies, arthrodesis, and tendon transfers. This chapter only focuses on Stage I PCFD and does not include treatment options for the rigid hindfoot. Essential components of PCFD include hindfoot valgus (A), midfoot abduction (B), forefoot varus (C), peritalar instability (D), and ankle valgus deformity (E). It is important to recognize that any one class may be flexible (Stage I) or rigid (Stage II) and will need to be addressed accordingly.