An electron microscopic study of the fascia from the medial and lateral sides of clubfoot.

Two cell types were observed in fascia from the lateral side of the clubfoot: a cell resembling the fibroblast of hypertrophic scar and a fibroblast-like cell with dilated rough endoplasmic reticulum. Three cell types were observed in fascia from the medial side of the clubfoot: typical fibroblasts, cells resembling myofibroblasts, and mast cells. The contracture of the medial side may be due to the myofibroblast-like cells, and this contracture may be enhanced by histamine released from the mast cells. The stretching of the lateral side is probably due to a compensatory fibrosis that maintains the tissue density.