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:
-
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.
-
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.
-
Central nervous system and spinal cord are
malformed. In these cases, Arthrogryposis is usually accompanied
by a wide range of other conditions.
-
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.
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