Arthrogryposis (multiple congenital contractures): diagnostic approach to etiology, classification, genetics, and general principles.

Arthrogryposis has been the term used to describe multiple congenital contractures for over a century. It is a descriptive term and present in over 400 specific conditions. Responsible gene abnormalities have been found for more than 150 specific types of arthrogryposis. Decreased fetal movement is present in all affected individuals which leads to a variety of secondary deformations. Decreased fetal movement (fetal akinesia) is associated with increased connective tissue around the immobilized joint, skin dimpling overlying the immobilized joint, disuse atrophy of the muscles that mobilize the joint and abnormal surface of the joint depending on the immobilized position. Other frequently observed features include: micrognathia, mildly shortened limbs, intrauterine growth restriction, pulmonary hypoplasia and short and/or immature gut. Primary etiologies include neuropathic processes; myopathic processes; end-plate abnormalities; maternal illness, trauma and drugs; limitation of fetal space; vascular compromise; and metabolic disorders to the developing embryo/fetus.