Pamphlet on AMC: "What it is and How it is Treated"

Contents:

What is Arthrogryposis?
Can Arthrogryposis occur again in the same family?
What causes it?
What is the treatment?
What is the outlook?
Medical Advisors

what is arthrogryposis?

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

In some cases, few joints maybe 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 joint contractures are accompanied by muscle weakness which further limits movement.

Arthrogryposis is relatively rare, occurring in perhaps 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 it?

Research on animals has shown that anything which 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 which 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 which transmit nerve impulses to the muscles.
2. There is not sufficient room in the uterus for normal movement. For example, the mother may lack normal amount of amniotic fluid, or have an abnormally shaped uterus.
3. Central nervous system and spinal cord are malformed. In these cases, Arthrogryposis is usually accompanied by a wide range of other conditions.
4. Tendons, bones, joints or joint linings may develop abnormally. For example, tendons may not be connected to the proper place in a joint.

what is the treatment?

For most types of Arthrogryposis, physical and occupational therapy has proven very beneficial in improving muscle strength and function and increasing 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) maybe used on knees and feet so that the joints can be moved and muscles exercised periodically. In some cases, merely wearing a splint at night may be sufficient.

Surgery should be viewed as a supportive measure to other forms of treatment when they have achieved their maximum result. Surgeries are commonly performed on ankles to put feet in position for weight-bearing and walking. Less frequently, surgery is required on 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.

In the past, surgeries were often repeated since the deformities reoccurred. With newer surgical techniques and careful follow-up treatment with physical therapy and splints, surgical success appears to be much improved. However, before any surgery is performed, it is important to be aware of the risks and the amount of improvement which can be expected. It is wise to seek a second or even a third opinion before proceeding with surgery. If possible, talk to someone who's child has had a similar surgery.

Since the term Arthrogryposis refers to a group of relatively rare conditions, few therapists or doctors have dealt with very many cases. Therefore, it is advisable to contact doctors and therapists in treatment centers where a large number of patients with Arthrogryposis are seen. Click here for the location of treatment centers near you.

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. That is, it does not worsen with age. Furthermore, with physical therapy and other available treatments, substantial improvement in function is normally possible. Most people with Arthrogryposis are of normal intelligence and are able to lead productive, independent lives as adults.

medical advisors

Judith Hall, M.D.
Director of Pediatrics
British Columbia's Children's Hospital
4480 Oak Street
Vancouver, British Columbia V6H 3V4
Canada

Lynn Staheli, M.D.
Director of Orthopedics
Children's Orthopedic Hospital and Medical Center
4800 Sand Point Way N.E.
Seattle, Washington 98105
United States

The printing of this booklet was made possible by a grant from the THOMAS LECHMAN MEMORIAL FUND. It may be reproduced without written permission from Avenues.