Double arthrodesis in the adult.

Twenty-four double arthrodeses (24 patients) were evaluated at an average of 56 months postoperatively. Sixteen arthrodeses were performed for adult acquired flatfoot attributable to posterior tibial tendon insufficiency (16 patients), and results were compared with the results of eight patients undergoing arthrodesis for other diagnoses. The overall satisfaction rate was 83%, with 76% of patients having good and excellent results. Considerable improvements were observed in pain and function indices, with similar outcomes observed in the patients with and without acquired flatfoot. However, complications were more frequent in the patients who had flatfoot deformities. Clinical deformity was corrected reliably and radiographic parameters confirmed correction of deformity. Progression of arthrosis in the surrounding joints was common, but most patients were asymptomatic. Talonavicular nonunion was the most frequent complication, occurring in four patients. Three of the patients underwent revision arthrodesis.