Frequently Asked Questions
What is Arthrogryposis Multiplex Congenita (commonly called AMC)?
Arthrogryposis Multiplex Congenita is a condition that causes many joints to be stiff and crooked at birth. A newborn with Arthrogryposis lacks the normal range of motion in one or more joints. A joint that lacks normal range of motion is called a joint contracture. These joint contractures develop before birth (prenatally) and are evident at birth (congenitally). Arthro means joint, Gryposis means crooked, multiplex means multiple and congenita means existing at birth or present at birth. Arthrogryposis Multiplex Congenita is an umbrella and descriptive diagnosis. This means Arthrogryposis can be caused by an underlying condition or syndrome. This underlying condition is usually the type of Arthrogryposis.
Which joints are affected by AMC?
Joints that can be affected by AMC include the hands, feet, hips, knees, elbows, shoulders, wrists, fingers, toes, the jaw and the spine. Any and all joints can be affected but it is possible for some joints to be unaffected. No two people are affected exactly the same way.
How does AMC affect the joints?
The range of motion in the joints of the arms and legs is usually limited or fixed. This lack of joint mobility is often accompanied by overgrowth (proliferation) of tissue. This is called Fibrous Ankylosis.
How does AMC develop?
At about the 5th to 6th week of pregnancy, the baby (called an embryo at this point) begins to develop joints. The joint spaces develop by 7 weeks, and the limbs can be seen moving by 8 weeks of pregnancy. This motion of joints is clearly important, as it allows the joints and structures around the joints (skin and ligaments, for example) to develop. If the joints do not move for any reason when the baby is a fetus (after 8 weeks of pregnancy) the baby will be born with joint contractures. The lack of joint motion when the baby is a fetus is known a fetal akinesia.
What causes limitation of joint motion before birth?
Fetal Akinesia (lack of joint motion during prenatal development) can be caused by many things such as problems with the muscles, problems with the nerves going to the muscles, a problem with the signals coming from the spinal cord or a problem with the brain.
The most common type of Arthrogryposis is called Amyoplasia. Amyoplasia is thought to be caused by a single unexplained event that interrupts normal development of muscle. If the muscle doesn't develop normally the joint cannot move and develop thus leading to fetal akinesia and Arthrogryposis present at birth. This unexplained event is not caused by anything the pregnant mother does or does not do.
Are there different types of AMC?
AMC is a sign of many specific conditions and syndromes. This means that AMC is caused by or can co-exist with other congenital problems that are part of an underlying diagnosis. This underlying diagnosis (a condition or a syndrome) is the type of AMC. There are approximately 400 types of AMC or 400 conditions and syndromes that have congenital joint contractures (Arthrogryposis) as part of it. There are four basic groups that babies born with AMC can be divided into: Those with only limbs affected, those with limbs and trunk involvement, those with limb, head/face and organ involvement, and those with limb involvement and severe central nervous dysfunction.
What is a Geneticist?
A Geneticist is usually the doctor who determines the type of AMC. A geneticist is a doctor who has special training in genetics. Geneticists are specially trained to look at all aspects of the body and understand what is considered typical. Things they may look at are ear shape, closeness of the eyes, and the length of the limbs. They will also closely examine the joint contractures. By knowing what is typical in a newborn they can easily see the little abnormalities present in a child born with issues as well as the most apparent issues. These little issues may help determine the type of AMC.
Proper diagnosis of the type of AMC is important because if there are more serious underlying issues this may affect long-term prognosis and treatment.
A genetic counselor may also work with a geneticist. A genetic counselor is a health care professional that holds a masters degree and is trained to help families understand genetic conditions.
It is recommended that you seek out a geneticist who has an interest in Arthrogryposis.
How is the type of AMC determined?
The type of AMC is usually determined by how the contractures present at birth, what joints are affected at birth, if there are issues with other body areas and systems such as the head/ face and the organs.
Other than a physical examination there are several non-invasive and invasive tests that can be done (but are not always necessary) to help determine the type of AMC. These tests can include: An MRI of the brain and the spine to determine if these organs are affected. A muscle Biopsy can be done to look at the fibers of the muscles to determine if they are normal or abnormal. And blood can be taken to look at the chromosomes to determine if there is a problem with them.
If the type of AMC cannot be determined upon first evaluation don't be discouraged. Some aspects of AMC become more obvious over time. It's recommended that your child is seen yearly by a geneticist.
What is the long-term outlook for a child born with AMC?
The great majority of people affected with AMC enjoy a normal lifespan. However, it is important to determine if there are problems with the spine, chest wall or brain, and if they are involved close monitoring is necessary to avoid and manage possible life-threatening problems. About 50% of infants that have central nervous system dysfunction along with the joint contractures do not make it through their first year.
Infants born with AMC should have their respiratory status evaluated closely if they encounter an upper respiratory infection, the underdeveloped chest/abdomen muscles and/or spinal deformities can compromise an infant's ability to manage the congestion involved with an upper respiratory infection.
Does AMC get better?
People with AMC look their worst at birth. AMC is considered non-progressive, so with proper medical treatment, things can improve. The joint contractures that are present will not get worse than they are at the time of birth. There is no way to completely resolve or cure AMC. But with proper treatment, most children make significant improvements in their range of motion and ability to move their limbs which enables them to do activities of daily life, and live relatively normal lives. With therapy, the contractures frequently improve dramatically! Therapeutic interventions that are cornerstone in the treatment of AMC include: stretching and range of motion exercises, physical, occupational, and speech therapy, splinting and serial casting. Surgical intervention may also improve joint mobility and function.
How do you treat AMC?
Treatment for AMC often includes: stretching, range of motion exercises, splinting, serial casting, physical therapy, occupational therapy, and bracing. Clubfoot is a very common deformity of the feet in babies with Arthrogryposis. A method of serial casting called the Ponseti Method is a common approach to correcting the clubfeet. This method can eliminate the need for major clubfoot surgery in infancy. Serial casting is when a joint is stretched and held in that stretch by a cast. Each week the cast is removed and the joint is stretched again and casted. This is repeated weekly until the joint is at its ideal position or a specific amount of range of motion is achieved.
Orthopedic surgery can be done for the joint contractures that are resistant to therapy, stretching and casting. Surgical intervention may include osteotomies (bone cuts) and tendon/ muscle lengthening.
Once gains have been made in joint position and range of motion it is important to use custom-made splints and braces to maintain joint position and motion.
Joint contractures can be difficult to manage and you may, at times, experience regression of gains that have been made with therapies, casting or surgery. Regression is a common occurrence and can happen despite bracing and splinting. It happens because as the child with AMC grows the connective tissues may not be able to lengthen at the same rate as the child's growth causing joint contractures to recur.
Are there any non-joint related problems?
The caregivers of a child with AMC should be aware that there can be problems associated with the administration of anesthesia during surgical procedures. Anesthesia is the combination of drugs administered to put the child to sleep during the procedure. If the child has facial or spinal issues or a limited jaw opening intubation can be difficult or impossible.
Individuals with AMC may also be more susceptible to the respiratory depressant effects of anesthesia because of their muscle weakness, underdevelopment of the lungs or spinal deformities. It is important to inform the Anesthesiologist of your child's diagnosis, even if the surgery has nothing to do with AMC. The Anesthesiologist is the doctor who administered the Anesthesia.
Undescended testes can also be an unseen issue in children with AMC.
Children with AMC often have eating difficulties that come from a limited jaw opening or poor muscle strength/ coordination when swallowing. Some children will require a tube placed directly in the stomach to be fed. This is called a G-tube.
A limited jaw opening and the poor muscle strength/ coordination in the throat and face can also cause breathing difficulties. Some children with AMC may require a tracheotomy to breath. A tracheotomy is an opening in the neck that allows breathing without using the nose or mouth.
The overall development of a child with AMC should be followed by a medical professional. Developmental skills such as fine motor skills, gross motor skills, oral and speech development and social development should be followed closely.
So what can and can't people with AMC do?
Most individuals with AMC have normal intelligence. So the limitations a person with AMC may have are usually only physical. How physically limited a person with AMC is or is not will depend on how they are affected. Some individuals with AMC are very mildly affected and they have very few physical limitations. Others are much more affected and may require assistance from a personal aide to perform daily activities. Some people with AMC walk independently; some may need a wheelchair for mobility. Adults living with AMC are doctors, lawyers, architects, authors, artists, teachers, parents, social workers among other things!
What if I am pregnant with a baby with AMC?
If you are pregnant, and arthrogryposis is diagnosed through ultrasound findings, Dr. Judith Hall, one of the most knowledgeable geneticist on the subject recommends "in-utero therapy" during the third trimester, if cleared by your obstetrician:
Drink Coffee or Tea 3x a day
Take 10 deep breaths 3x a day
Keep Moving. Exercise!
Take 10 minute fast walks at least 1x a day
She also suggests discussing with your obstetrician the possibility of delivering the baby 2-3 weeks early, if the baby is healthy enough (lungs are developed). That will allow the contractures to be treated sooner. You may also want to talk with your doctor about delivering by C-section to reduce the risk of fractures, to which babies with AMC are more prone during the newborn period.
Not all patients have the same medical and pregnancy history. Always talk with your physician before changing medications or lifestyle changes.
I found out my baby has AMC when she was born. How do I take care of her?
Your baby may appear fragile to you, in most cases of AMC they are not. You will still love them and care for them as any other baby.
Dressing or diapering maybe more difficult because of the lack of joint motion. If your baby gets casts or splints before leaving the hospital make sure you have instructions on how to care for the casts and how often the splints need to be worn.
It is usually most beneficial to begin stretching and range of motion exercises immediately, while still in the hospital if possible. If your doctor does not recommend immediate stretching, make sure you understand and agree to the reasons they give you. As always, don't be afraid to seek a second opinion.
Is assistance available for my child with AMC?
Your child will most likely qualify for early intervention services. Early intervention services include access to physical and occupational therapists and help in keeping your baby progressing in developmental milestones. Most states provide early interventions services free of charge.
Your child may also qualify for financial medical assistance through state level waivers or medicaid. Talk to a hospital social worker, they can direct you to the appropriate programs. If you are out of the hospital, call your local Department of Health, and they should be able to direct you.
Programs vary widely from one state to another. It is to your benefit to educate yourself on the programs and assistance that is available to you and your child in your area.
Can people with AMC have kids?
Woman and men with Arthrogryposis have had children. It is recommended that an adult with AMC whom is planning to have a child seek advice from a medical professional.
We encourage new parents to join our support group forums: http://www.amcsupport.org/forum/. There are answers to these questions above and many more from caregivers of children with AMC that have been where a new parent is.
Use permitted without fee with the following acknowledgement: In print material, the following notice must appear on the first page of each material used from AMCSI documents:
Reproduced with permission, © 2011 by Arthrogryposis Multiplex Congenita Support Inc. www.amcsupport.org. All rights reserved.
In electronic material, the following notice must appear on the first page of each material used from AMCSI documents: Reproduced with permission, © 2011 by Arthrogryposis Multiplex Congenita Support Inc. www.amcsupport.org. All rights reserved.