Severe Equinovarus Deformity Research Articles

Part I. Amyoplasia: a common, sporadic condition with congenital contractures.

A specific congenital contracture (arthrogryposis) syndrome has been recognized in 135 out of 350 patients with various kinds of congenital contractures. This sporadic syndrome, designated amyoplasia is characterized by absence of limb muscles that are replaced by fibrous and fatty tissue. At birth there is characteristic positioning of the limbs with internal rotation at shoulders, extension at elbows, and flexion of the hands at the wrists. Severe equinovarus deformities of the feet are usually present. Contractures at knees and hips occur in a variety of positions. Typically, the face is round with a frontal midline capillary hemangioma and slightly small jaw. Intelligence is normal. Approximately 63% of our patients had involvement of four limbs (almost always symmetrically), 24% mainly of lower limbs, and 13% mainly upper limbs. Typically, no other malformations are present. However, minor anomalies are seen often, and include hypoplastic digits and hypoplasia of scrotum or labia, the umbilical cord may be wrapped about a limb at birth. In utero fetal activity is decreased and breech delivery is increased in amyoplasia. All cases were sporadic; identical twins are discordantly affected.

722 AMYOPLASIA: A DISTINGUISHABLE FORM OF ARTHROGRYPOSIS

A specific type of arthrogryposis has been recognized among 135 (39%) patients in a study of over 350 patients with congenital contractures of the joints in 2 or more body areas. It was designated “amyoplasia” because the condition is characterized by absence of muscle tissue with fibrosis and fatty replacement. A characteristic positioning of the limbs is present at birth. Intelligence is normal and the condition appears to be sporadic with no known familial recurrence. Chances of survival are excellent but disability can be marked. Early mobilization with physical therapy is important. An excess (11/135) of discordant identical twins has been observed.Typically, the shoulders are internally rotated with decreased muscle mass, the elbows are usually extended (70%) with flexion contractures of the wrists and hands. Severe equino varus deformities of the feet are seen in about 90% of the patients. Most affected patients have 4-limb involvement (85/135; 63%), but some have mainly upper limb involvement (17/135; 13%) and others have mainly lower limb involvement (33/135; 24%). The face is usually round with a midline hemangioma. In general, there are no associated visceral malformations; however, deformation anomalies are seen at a higher frequency than expected (amniotic bands, smashed digits, cord wrapping, skin tags, cryptorchidism, craniosynostosis, dislocated radial head, scoliosis, etc.). Pathological studies of muscle and spinal cord have been non-specific.