The earliest known Italian case of bilateral non-osseous calcaneonavicular coalition from the mediaeval cemetery of Troina (Enna, Sicily)

In this article, we detail a case of tarsal coalition in the osteological remains of an adult female individual from the mediaeval cemetery of the Catena district of Troina (Enna, Sicily). The burial that contains the skeleton described in this work (Burial 2) was subjected to a multidisciplinary analysis starting from the excavation on the field and ending with a full palaeopathological study including palaeoradiology and 3D virtual reconstructions. The obtained results contribute to our understanding of this congenital condition in the past and represent, to the best of our knowledge, the first case ever reported from Sicily and the Italian peninsula of bilateral non-osseous calcaneonavicular tarsal coalition.