Five club feet and three normal feet of fetuses aborted at sixteen to
twenty weeks of gestation were studied by making serial histological
sections cut in the sagittal, frontal, and transverse planes. In the club
feet we found gradations in the severity of the following abnormalities: 1.
Altered shape, size, and relationships of the tarsal bones. 2. Decrease in
the size and number of fibers in the distal third of the muscles of the
posterior and medial aspect of the leg; increased fibrous connective tissue
in these muscles, their tendon sheaths, and the adjacent fasciae; and
shortening of the triceps surae. 3. Thickening of the distal parts of the
tendo archillis and of the posterior tibial tendon. 4. Ligaments on the
posterior and medial aspects of the ankle joint pulled into the joint by
the severe plantar flexion and varus displacement of the talus, and marked
shortening and thickening of the tibionavicular and plantar
calcaneonavicular ligaments. On the basis of these pathological findings,
the possibility of a retracting fibrosis as the primary etiological factor
of the club-foot deformity should be considered.