Arthrogryposis

What is arthrogryposis (arthrogryposis multiplex congenita)?

Arthrogryposis (arthrogryposis multiplex congenita, AMC) is a characteristic of over 300 disorders, including muscular dystrophy and trisomy 18 (Edwards syndrome). It refers to the occurrence of more than one contracture at birth. A contracture is a congenital anomaly that causes permanent tightening of your baby’s muscles, skin and tendons that make their joints short and stiff. Arthrogryposis means crooking (bending) of the joint. “Artho” means joint, and “gryposis” means crooking.

People with arthrogryposis are born with joints that are difficult to move — the joints might be fixed, curved or straight joints frozen in place. Your joints are where two or more bones connect. Examples of joints in your body include your:

• Wrists.
• Hips.
• Knees.
• Neck.

Babies with arthrogryposis are born with several distinctive features, including:

• Sloped shoulders rotated toward the center of their body.
• Extended elbows.
• Curled wrists and fingers.
• Dislocated hips.
• Extended knees.
• Feet pointed downward and inward.
• Their spine curved sideways.

What are the types of arthrogryposis?

There are a couple of types of arthrogryposis, including:

• Amyoplasia is when contractures happen in your limbs.
• Distal arthrogryposis is when the contractures happen in your hands and feet but not your larger joints.

How common is arthrogryposis?

Arthrogryposis is uncommon. It occurs in 1 in 3,000 live births.

Is arthrogryposis (arthrogryposis multiplex congenita) genetic or hereditary?

Arthrogryposis is congenital, meaning the symptoms begin before birth. The cause of arthrogryposis is often unknown. But genetic diseases might cause it. Experts have identified more than 400 altered (mutated) genes that affect arthrogryposis, and arthrogryposis is linked to over 35 genetic disorders.

What’s the difference between arthrogryposis and an isolated congenital contracture?

Isolated congenital contractures happen only in one area of your body instead of two or more areas. One example of an isolated congenital contracture is clubfoot.

What causes arthrogryposis (AMC)?

In most cases, the exact underlying cause of arthrogryposis is unclear. However, the most common possible causes of arthrogryposis include:

• Limitation of fetal movement during development caused by insufficient amniotic fluid, another fetus in the uterus or an unusually shaped uterus. If the fetus can’t move its joints, then excess tissues form around those joints.
• A disorder in the pregnant person like multiple sclerosis. Your risk of multiple sclerosis increases if someone in your family has it.
• A genetic disorder like muscular dystrophy.
• Diseases of your central nervous system, including Moebius syndrome and spina bifida (meningomyelocele).
• Diseases of your neuromuscular system, including myasthenia gravis.
• Diseases of your connective tissues, including dysplasia and metatropic dwarfism.

In some cases, the cause of arthrogryposis is likely a combination of genetic and environmental issues.

What are the symptoms of arthrogryposis?

The signs and symptoms of arthrogryposis can vary from person to person. One person’s symptoms might be different or more severe than another’s, even within the same family.

Universal symptoms that everyone with arthrogryposis experiences include:

• A limited ability to move small and large joints.
• An inability to move small and large joints.
• Underdeveloped muscles (hypoplastic muscles).
• Soft, tube-shaped limbs.
• Soft tissue webbing over your joints that keep your joints from moving.

Additional symptoms a majority of people with arthrogryposis experience include:

• Extra slender and fragile long bones in your arms and legs.
• Undescended testes (cryptorchidism).

Symptoms that a smaller percentage of people with arthrogryposis have include:

• Dislocated hips, elbows or knees.
• Problems with the structure of the central nervous system (your brain and spine).
• Problems with the functions of the central nervous system (the way it works).

People with amyoplasia usually don’t have issues with their internal organs or cognitive function. But 10% have issues with their abdomen. Abdominal problems include:

• Gastroschisis is a hole in your abdomen.
• Intestinal atresia is a blocked intestine.

Leg joints are affected more than any other joint, with arms next in line. Other commonly affected joints include your:

• Shoulders.
• Knees.
• Elbows.
• Ankles.
• Fingers.
• Wrists.
• Toes.
• Hips.
• Jaw.

How long does arthrogryposis (AMC) last?

Arthrogryposis doesn’t go away, but there are some treatments that can improve your quality of life. Physical therapy helps with everyday tasks like getting dressed and drinking water.

How is arthrogryposis (AMC) diagnosed?

Sometimes, a fetus is diagnosed with arthrogryposis before birth. Routine ultrasounds can reveal atypical limbs that might mean the fetus has arthrogryposis. Usually, your healthcare provider discovers the contractures during the second trimester of pregnancy. Your healthcare provider might recommend genetic counseling.

Your genetic counselor should give you information about the genetic conditions that might affect the fetus. They’ll interview you about your family health history and recommend genetic tests, including:

• Chorionic villus samplings.
• Amniocentesis.

Healthcare providers can also diagnose arthrogryposis after your baby’s born by observing their symptoms and performing tests like:

• Nerve conduction measures how quickly nerves transport electrical impulses.
• Electromyography records electrical activity in their muscles.
• Muscle biopsy is where a small amount of muscle is removed and studied.
• Genome sequencing identifies the altered genes.
• Blood tests look for gene and chromosome abnormalities.
• A comparative genomic hybridization (CGH) array detects chromosome changes.
• A microarray analyzes thousands of genes at once.
• Exome studies identify gene variations.

Healthcare providers sometimes also rely on imaging tests, including:

• Ultrasound.
• Electromyography (EMG).

Your healthcare provider will create a treatment plan once they identify a possible underlying cause of the arthrogryposis. You can help develop that plan.

How is arthrogryposis (AMC) treated?

Although there isn’t a cure for arthrogryposis, treatments can improve your child’s quality of life.

The treatments are different for each person because the probable causes of arthrogryposis are different for everyone.

The most common types of treatment for arthrogryposis include:

• Casts that move stiff joints.
• Physical therapy that improves joint motion and prevents muscle atrophy (when the muscles waste away).
• Joint manipulation, a type of therapy where joints get gently moved.
• Stretching exercises increase flexibility and range of motion.
• Surgery on ankles, hips, knees, wrists or elbows can also increase the range of motion. The goal is to improve your child’s function by detaching bones from tissues that stop them from moving and forcing the muscles to flex and move. Surgery is rare.

Experts recommend a multidisciplinary approach. Your child might need more than one type of treatment.

Do I need to see a specialist?

You’ll need to see specialists who help with your child’s arthrogryposis. A pediatrician, orthopaedist, neurologist, medical geneticist, rehabilitation physician and physical therapist might all be involved in the care of your child.

Are there any at-home treatments for arthrogryposis?

Most people with arthrogryposis need to do physical therapy well into their teenage years. There are some exercises that physical therapists can teach you to do at home.

How can I prevent arthrogryposis (AMC)?

Preventing arthrogryposis is out of your hands. There’s nothing you could’ve done to reduce your child’s risk of arthrogryposis.

What is the outlook for arthrogryposis (AMC)?

The long-term outlook for people with AMC depends on a few circumstances, including:

• The severity of the arthrogryposis.
• The underlying cause of arthrogryposis.
• How your or your child’s body responds to therapy.

The majority of people with arthrogryposis grow up to be independent adults. Treatment helps them improve their mobility to the point that they can lead lives similar to people who don’t have arthrogryposis.

Does arthrogryposis get worse?

Arthrogryposis isn’t progressive. Although arthrogryposis doesn’t get worse, the underlying condition that causes it might. You might want to educate yourself about the possible cause of your child’s arthrogryposis when your healthcare providers confirm it.

What questions should I ask my healthcare provider about arthrogryposis?

Asking questions can help you gain a better understanding of arthrogryposis. Consider asking your healthcare providers the following questions about your baby's diagnosis:

• What type of arthrogryposis does my child have?
• How long will my baby have to be in a cast?
• What’s the best treatment for my child?
• What specialists should my child see?
• When do we start physical therapy?
• Are there medications that my child should take?
• How can I best help my child?

A note from Cleveland Clinic

People with arthrogryposis are born with stiff or frozen joints. Everyday activities like walking and holding a cup may be difficult. Most people require physical therapy and sometimes surgery to improve their quality of life.

The very last thing a parent wants to hear is that there’s something wrong with the fetus or their infant. Try not to blame yourself. There’s nothing you could’ve done differently. Talk to your healthcare provider about counseling and support groups if you need help coping with this difficult situation. You’re not alone. There are other families in similar situations.