Symposium: Adult acquired flatfoot deformity.

Most of the controversy surrounding management of the adult acquired flatfoot deformity revolves around the correction of Stage II deformity. Stage I deformity, uncommonly corrected surgically, involves tenosynovitis with preservation of tendon length and absence of structural deformity. Attempts at tenosynovectomy in light of structural deformity leads to operative failure, found in 10% of Teasdall and Johnson’s 1992 patient population. Thus, with tenosynovectomy rarely becoming an operative situation, Stage II deformity is the most common problem requiring operative treatment of the adult flatfoot. Stage II deformity patients present with swelling medially, the inability to do a single heel raise, with a passively correctable subtalar joint. The tendon is functionally torn. In recent years, authors have subdivided Stage II deformity even further into A and B subcategories, where A involves less than 50% uncovering of the talonavicular joint, and B more than 50%. Recently, Anderson has added a C subtype, which may be applied to either A and B patients, in patients who have forefoot varus. Thus, Stage II patients suffer from pain that begins medially and progresses to the subfibular region over time. Most important, recognition of the continued sub-classification in Stage II disease echoes the fact that this disorder is on a continuum, challenging the surgeon to recognize subtleties that, if unrecognized, lead to a poor patient outcome.