[Congenital tarsal synostosis].

Tarsal coalition results from the fusion of at least two tarsal bones. The clinical and radiological pictures depend on the anatomic location of the coalition. Calcaneonavicular and talonavicular coalitions are the most frequent features which may result in peroneal spastic flat foot; however they are symptomless in most cases. Tarsal coalitions are usually evident on plain X-ray films using appropriate incidences. In selected cases, partial talocalcaneal coalition requires CT scan or MRI. No treatment is needed for asymptomatic conditions. Painful spastic flat foot must be treated conservatively by limiting sport activity as a first step treatment. In case of persistent symptoms, cast with correction of deformities under general anesthaesia is recommended. Surgery is needed only in case of failure of previous treatment, requiring resection of the bony bridge and sometimes triple foot arthrodesis.