The syndrome of arthrogryposis multiplex congenita.

Arthrogryposis Multiplex Congenita (AMC) is a syndrome characterized by confenital rigidity or "clubbing" of multiple joints. Soft-tissue ankylosis restricts the motion of the joints, which are fixed in postures dictated by the position of the embryo during development. The joint malformations result from relatively brief immobilization of the developing embryo due to a variety of factors. This concept of pathogenesis derives support from the experimental reproduction of AMC in chick embryos paralyzed by a variety of pharmacologic agents. In man, prenatal disorders which are capable of immolilizing the embryo give rise to AMC. These disorders may affect the brain, spinal cord, peripheral nerves, or muscles. Various mechanical factors that restrict the embryo's movements can also produce joint malformations. Thus, AMC should be regarded as a syndrome of articular malformations which may stem from many different causes rather than as a disease entity.