TALOCALCANEAL COALITION A FREQUENTLY OVERLOOKED CONDITION.

Congenital tarsal coalition is a diagnosis that is often overlooked in young patients who first present with foot and ankle pain. Tarsal coalition is an abnormal fibrous, cartilaginous or osseous fusion of two or more tarsal bones [1]. The prevailing etiologic theory for congenital coalitions is failure of complete segmentation of mesenchyme with the absence of normal joint formation. Approximately 50%?80% of cases of tarsal coalition are bilateral [2] and more than 90% of coalitions are located between the calcaneus and the navicular or between the talus and calcaneus [3]. Calcaneonavicular and talocalcaneal coalitions have been reported to occur in approximately equal frequency [4]. However, recent investigations suggest that calcaneonavicular coaltions occur 3 times more frequently [5].