arthrogryposis multiplex congenita [Gk, arthron + gryposis, joint curve; L, multus, many, plica, fold, congenitus, born with] , fibrous stiffness of one or more joints, present at birth. It is often associated with incomplete development of the muscles that move the involved joints and degenerative changes of the motor neurons that innervate those muscles. The cause of the condition, which is uncommon, is unknown, although possible causes are fetal crowding and maternal neuromuscular disease. Physiotherapy to loosen the joints is the only treatment. Also called amyoplasia congenita.
