Gross and histological abnormalities of the talus in congenital club foot.

Gross and histological abnormalities were demonstrated in a club-foot talus from a boy with multiple congenital anomalies who died when he was nine days old. Both tali were studied, the one from the club foot and the one from the normal foot. The gross anomalies involved the smaller size of the club-foot talus and the increased medial deviation of a stunted, misshapen head and neck region. Serial histological sections of both tali allowed for a three-dimensional geometric appreciation of both bones and an assessment of the nature and extent of histological and cytological features. The ossification center of the club-foot talus was absolutely and relatively smaller than that of the normal talus. It was eccentrically positioned, being more lateral and anterior than that of the normal talus. The marked histological abnormalities seen in the head and neck region of the club-foot talus involved extensive breaching of the endochondral sequence by vessels. The posterior aspect of the endochondral sequence and ossification center was normal. The extra-osseous and intra-osseous blood supply of the two tali was normal with the exception of the increased and irregular breaching of the endochondral sequence in the club-foot talus. This study demonstrates histological abnormalities in the head and neck region of the club-foot talus, which was most abnormal grossly. The eccentric position of the secondary ossification center as well as its related vascular abnormalities do not support a theory of developmental arrest of the talus but appear sufficiently abnormal to support the theory of a primary defect in the cartilage anlage. Clinically, one must bear in mind that early open reduction of the talocalcaneal navicular joint in a foot such as this would have served to reposition the navicular onto a talus that still was structurally abnormal.