Arthrogryposis

Arthrogryposis is a non-progressive muscle disorder causing multiple joint contractures (limitation in the range of motion of a joint) at birth. In some cases, few joints may be affected and the range of motion may be nearly normal. Hands, wrists, elbows, shoulders, hips, feet and knees may be affected. In severe cases, nearly every body joint may be involved, including the jaw and back. Frequently, contractures are accompanied by muscle weakness, further limiting movement. Arthrogryposis is relatively rare, occurring in approximately one in 3,000 births. In most cases, arthrogryposis is not genetic and does not occur more than once in a family. In about 30% of the cases, a genetic cause can be identified. The risk of recurrence for these cases varies with the type of genetic disorder. Lack of joint movement in utero can cause the contractures.

The most common type of arthrogryposis, amyoplasia, occurring once in every 10,000 live births, is characterized by symmetrical stiffness of the limbs. Joints are fixed in bent or straight positions or severely limited in motion and muscles are thin. Amyoplasia does not appear to be genetic in origin.

Treatment

For most types of arthrogryposis physical and occupational therapy has proven beneficial in improving the range of motion of affected joints. Parents are encouraged to become active participants in a therapy program and to continue therapy at home on a daily basis.

Splints can be made to augment the stretching exercises to increase range of motion. Casting is often used to improve foot position, but emphasis should be placed on achieving as much joint mobility as possible. Removable splints may be used on knees and feet to allow exercise; in some cases, wearing the splint at night may be sufficient. Occupational therapists can often make or provide devices to increase independence in the areas of feeding, hygiene, dressing, and school activities such as writing or using a keyboard.

Surgery may be necessary to address the congenital deformities frequently occurring in conjunction with arthrogryposis. Surgery on feet, knees, hips, elbows and wrists may also be useful if more range of motion is needed after therapy has achieved maximum results. In some cases, tendon transfers can improve function. Congenital deformities of the feet, hips and spine may require surgical correction at or about one year of age.

In most cases, the outlook for those with arthrogryposis is positive. Substantial improvement in function is usually possible. Cognitive involvement in cases of arthrogryposis is rare, and people with the condition can lead productive, independent lives as adults.

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