Anatomical study for an update comprehension of clubfoot. Part I: Bones and joints

The aim of our study was to elucidate the gross anatomical changes of bones and joints in idiopathic clubfeet.

Gross dissection was carried out on seven idiopathic clubfeet of fetuses aborted between the 25th and 37th week of gestation and compared to two normal feet (27th and 36th week of gestation). Particular attention was paid to the articular surfaces, shapes and angles of all bones and their skeletal relationships.

The talar neck–trochlea angle in clubfeet ranged from 37° to 41°, in normal feet from 27° to 33°. In clubfeet the deviation of the neck of the talus relative to the body was between 28° and 43°, in normal feet between 22° and 24°. The posterior joint surface was in an anterolateral position and even flat transversely. The head of the clubfeet tali was turned along a longitudinal axis in the opposite direction compared to the normal ones. Instead of a typically saddle-shaped posterior talar surface of the calcaneus, it was triangular and flat transversely, and a bony stability in the subtalar joint was not achieved. The angle of torsion of the calcaneus showed no significant difference between normal and clubfeet. The anterior surface was flat, medially twisted and orientated upwards.

We presume that the calcaneus is the primary fault, which might be explained by pathologic biomechanical forces during development.