Experimental study on the etiology of congenital multiple arthrogryposis.

The effect of temporary immobility of the muscles in the embryo, induced by continuous infusion of d-tubocurarine into the ovum, was studied in 31 chick embryos. The ankle and foot joints showed flexion contractures with equal frequency, but the knees were less severely affected. Histological examination demonstrated peri-articular and intra-articular fibrosis, and fibrosis of the muscles of the limb. These experimental lesions closely resemble those of arthrogryposis. It is therefore suggested that the aetiology of human arthrogryposis may be based on a common pathogenetic mechanism; lack of joint movement during embryonic life.