Arthrogryposis

What is arthrogryposis?

Arthrogryposis (Arthrogryposis Multiplex Congenita) is a term describing the presence of a muscle disorder that causes multiple joint contractures at birth. A contracture is a limitation in the range of motion of a joint.

In some cases, few joints may be affected and the range of motion may be nearly normal. In the "classic" case of arthrogryposis, hands, wrists, elbows, shoulders, hips, feet and knees are affected. In the most severe cases, nearly every body joint may be involved, including the jaw and back. Frequently, the contractures are accompanied by muscle weakness, which further limits movement. Arthrogryposis is relatively rare, occurring in approximately one in 3,000 births.

Can arthrogryposis occur again in the same family?

In most cases, arthrogryposis is not a genetic condition 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.

What causes arthrogryposis?

Research has shown that anything that prevents normal joint movement before birth can result in joint contractures. The joint itself may be normal. However, when a joint is not moved for a period of time, extra connective tissue tends to grow around it, fixing it in position. Lack of joint movement also means that tendons connecting to the joint are not stretched to their normal length; short tendons, in turn, make normal joint movement difficult. (This same kind of problem can develop after birth in joints that are immobilized for long periods of time in casts.)

In general, there are four causes for limitation of joint movement before birth:

1. Muscles do not develop properly (atrophy). In most cases, the specific cause for muscular atrophy cannot be identified. Suspected causes include muscle diseases (for example, congenital muscular dystrophies), maternal fever during pregnancy, and viruses, which may damage cells that transmit nerve impulses to the muscles.
2. There is not sufficient room in the uterus for normal movement. For example, the mother may lack a normal amount of amniotic fluid, or have an abnormally shaped uterus.
3. Central nervous system and spinal cord are malformed. In these cases, a wide range of other conditions usually accompanies arthrogryposis.
4. Tendons, bones, joints or joint linings may develop abnormally. For example, tendons may not be connected to the proper place in a joint.

Amyoplasia

Amyoplasia is the most common type of arthrogryposis, occurring once in every 10,000 live births. It is characterized by symmetrical stiffness of the limbs. Joints are fixed in bent or straight positions, or severely limited in motion. Muscles are thin. Amyoplasia has not been observed to reoccur in siblings or offspring.

Treatment

Shriners Hospitals for Children – Los Angeles offers a multidisciplinary, family-centered approach to enhance patient care and to promote the understanding of these diseases.

For most types of arthrogryposis, physical therapy has proven very 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. However, emphasis should be placed on achieving as much joint mobility as possible. Some type of removable splint (perhaps a bi-valve cast) may be used on knees and feet so that the joints can be moved the muscled exercises periodically. In some cases, merely wearing a splint at night may be sufficient.

Surgery may be used to treat the congenital deformities that frequently occur in conjunction with arthrogryposis or should be viewed as a supportive measure once physical therapy has achieved maximum results but more range of motion is needed. Surgeries are commonly performed on feet, knees, hips, elbows and wrists to achieve better position or greater range of motion. In some cases, tendon transfers have been done to improve muscle function. Congenital deformities of the feet, hips and spine may require surgical correction at or about one year of age.

Arthrogryposis team members include:

• Care Coordinator—Provides family and individual counseling and referrals to local
national and international resources

• Clinic Coordinator—Facilitates all aspects of patient care.

• Hand Surgeon—Treats deformities of the upper limbs.

• Occupational Therapist—Teaches self-care skills and provides splints and adaptive devices

• Orthopedic Surgeon—Treats deformities of the spine and limbs.

• Orthotist—Makes braces that facilitate functioning of all of the limbs

• Physical Therapist—Provides training in sitting, standing and walking. Adapts strengths for optimum mobility

What is the outlook?

There is a wide variation in the degree to which muscles and joints are affected in those with arthrogryposis. In some cases, arthrogryposis may be accompanied by other conditions, such as central nervous system disorders, which complicate the picture. However, in most cases, the outlook for those with arthrogryposis is a positive one. Unlike many other conditions, arthrogryposis is non-progressive; it does not worsen with age. Furthermore, with physical therapy and other available treatments, substantial improvement in function is usually possible. Most people with arthrogryposis are of normal intelligence and are able to lead productive, independent lives as adults.

Our goal is to help children reach their maximum potential. If you would like to receive an application for admission to Shriners Hospitals for Children – Los Angeles, please call us toll-free at (888) 486-5437.