Some new aspects in the pathology of clubfoot.

As part of a research project that is still in progress, 12 human embryos, fetuses, and one stillborn infant with clubfeet, were given injections of barium sulfate solution with China ink for correlated-contrast radiography and anatomic dissections of cleared specimens including histologic sections. The following observations suggested a vascular factor in the etiology of congenital idiopathic clubfoot: (1) the muscular, tendinous, fascial and other soft elements were not conspicuously abnormal; (2) radiologically and anatomically, all deformed feet had vascular abnormalities consisting of an ischemic area at the level of the sinus tarsi; (3) a wedge form, with its acute angle pointed towards the head of the talus, showed the disarrangement of the vascular network at the ischemic sinus tarsi area; (4) the vascular alteration was always more conspicuous in the early period of fetal life, being reduced to a simple knot of fatty infiltration and fibrous tissue in the older specimens and in the stillborn; (5) the vascular nucleus of the talus "Anlage" also was not in the normal location in the neck, but on the deformed side of the body; (6) the established deformity was well vascularized and characterized by a small area of necrotic fatty degeneration covering the infarction area (secondary to helicoidal movement pressures of the forefoot on the hindfoot). Five stages in the fetal development of clubfoot can be defined beginning with adduction of the forefoot and ending in complete equinovarus deformity.