Arthrogryposis and amyoplasia.

Arthrogryposis (multiple congenital joint contractures) is an uncommon problem. Because there are many causes, correct diagnosis is important to predict the natural history and determine appropriate treatment. Inconsistent terminology has caused confusion about both diagnosis and treatment. Amyoplasia, the most common type of arthrogryposis, is characterized by quadrimelic involvement and replacement of skeletal muscle by dense fibrous tissue and fat. Early physical therapy and splinting may improve contractures, but surgical intervention is often necessary. Aggressive soft-tissue releases in addition to casting may improve joint position. In more severe contractures, osseous surgery also may be needed. Deformity recurrence is common, particularly in skeletally immature patients.