Thank you to Tracey Schalk for writing these facts!

Arthrogryposis is defined as multiple congenital (from birth) joint contractures or multiple joints that are stuck in 1 position and have very little flexibility.

A newborn has to have 3 contracted joints in two different body areas to have a diagnosis of arthrogryposis.

Arthrogryposis in an umbrella diagnosis, which means that it is part of other many conditions and syndromes. These conditions and syndromes are usually referred to as the type of arthrogryposis. Currently there are 400 identified types of AMC. Amyoplasia, Distal and Escobar Syndrome are the more common types (but they’re still rare within the general population). Some individuals never have their type of AMC identified.

All types of Arthrogryposis occur 1 in 3,000 live births. Each type is than more rare from there. Amyoplasia occurs approximately 1 in 10,000 births. Sadly, about 20-30% of infants born with AMC won’t make it to their 1st birthday because they have severe central nervous system dysfunction or have a genetic type that is lethal and some baby’s don’t make it for unknown reasons.

Arthrogryposis is caused by an unborn baby not moving properly during fetal development. A baby has to move its limbs for proper joint development to happen. When a joint doesn’t move for a long period of time, it gets stuck and contracted. Why a baby fails to move its joints depends on the type of AMC. For example, In Amyoplasia (a non-genetic type), it happens the muscles fail to develop. In Escobar Syndrome (a genetic type) the messages that impact a person’s muscle movement is affected, the message isn’t able to get through very well making it more difficult for them to move.

Common joints contractures in arthrogryposis include: Clubbed feet or vertical talus, extended (straight) or flexed knees, dislocated and/or externally rotated hips, internally rotated shoulders, extended or flexed elbows, flexed wrists, adducted thumbs (stuck-in-palm), fingers fisted or extended.

Arthrogryposis is not curable but it is very treatable! Usually the goal of treatment is to make a person as independent as possible in activities of daily living (ADL’s). ADL’s are those things you do every day to take care of yourself (eating, dressing, eat).

Treatment for arthrogryposis usually involves: stretching (to increase joint range of motion), physical therapy to work on overall strength and gross motor skills (walking, standing), occupational therapy to work on fine motor skills and self-help skills (grasping, feeding), speech therapy to work on speech and oral motor skills, serial casting (including the Ponseti Method for clubfeet), splinting, bracing (AFO’s, KAFO’s) and orthopedic surgery (osteotomies (bone cuts) to change angle or rotation of a bone, soft tissue releases (releasing and lengthening tight muscles and tendons), muscle/tendon transfers (changes what body part a muscle/ tendon moves) and external fixators (metal frames that are applied over a deformity that is exceptionally rigid/tight and needs to be corrected slowly or to lengthen short bones). Some individuals opt for through the knee amputation. There are other therapies as well: hippo therapy (using horses for therapy), aqua therapy (therapy in a warm water pool) and massage therapy to name a few.

Arthrogryposis is considered an orphan condition by the National Organization for Rare Disorders, Inc. (NORD) because it affects less than 200,000 people in the United States. Statistically speaking, The US has 313 million people so about 104,000 people would have arthrogryposis but this doesn’t account for the babies who don’t survive infancy. Rare disorders and conditions are significantly less like to be researched.

1/3rd of all cases of arthrogryposis are amyoplasia type. Amyoplasia means a lack of muscle development, this means muscles can be completely absent (they just failed to developed during fetal development) and the ones that did develop can be weak or are not of normal size. Amyoplasia is not considered genetic because it doesn’t repeat in families however there is still no known definitive cause to explain why amyoplasia occurs.

Arthrogryposis can affect just the arms/hands (sometimes referred to as upper extremity only) or just the legs/feet (sometimes referred to as lower extremity only) or it affects all the limbs (sometimes referred to as all extremity). Having all 4 limbs affected is the most common.

Many people with arthrogryposis have other co-existing conditions. These other co-existing conditions may be part of their type of AMC. Some of these other co-existing conditions include: cleft lip and/or palate, an airway that is narrow, weak suck/swallow, gastroschisis (intestines on the outside), tethered spinal cord, facial birthmarks (also called stork bites, angel kiss), micrognathia (small or recessed jaw), vision and hearing impairments, plagiocephaly (abnormal head shape) and severe scoliosis (curvature of the spine) can cause lung problems. These other conditions can lead to needing trachs (a tube in the airway that helps with breathing), g-tubes (a feeding tube), hearing aides and cranial remolding orthosis (helmet).

The distal arthrogryposis types are characterized by the joint contractures being isolated or more severe in the distal joints, basically the hands and the feet. Distal means furthest from the core of the body), but other joints can be affected. Hands being clenched and fingers stuck in a fist and clubfeet are very common. Most distal types are genetic but some are not. There are approximately 10 types of Distal arthrogryposis.

Lack of movement during fetal development is called Fetal akinesia. The fetal akinesia leads to the arthrogryposis (joint contractures) but there are other signs in a newborn that they didn’t move properly while in the womb. Extra hair or long dark hair can be present in areas that lacked movement. There can also be dimples over joints that didn’t move correctly.

Babies born with arthrogryposis can have a very rough start in life. Many babies with AMC accidentally have their bones broken during delivery or during the neonatal period. The lack of movement can make their bones more brittle (this is not the same as brittle bone disease) and if the position of the contractures are not favorable for delivery (for example if a baby’s hips are externally rotated and knees stuck in flexion) a lot of force may be needed to deliver them, resulting in fractured bones. The thighbones (femurs) and the upper arm bones (humerus) are common bones to be broken. Some babies have their limbs fractured immediately after birth because their medical team doesn’t know how to move them yet. If AMC is detected before birth a c-section may be needed to try to avoid broken bones but even with a c-section it can still happen. Some kids continue to have fractures throughout childhood from accidental falls.

If a baby is diagnosed with arthrogryposis before birth it’s now recommended that the mother take steps to get the baby moving, because the more movement there is, the less rigid the contractures will be. At the 2009 AMC Conference, Dr. Hall (the top geneticist in the study of arthrogryposis) said that mothers should drink caffeine, exercise and take deep breaths often. All of those things will keep the baby moving as much as possible. She also recommended delivering at around 37 weeks if the baby’s lungs are mature so that physical therapy can be started sooner.

With treatment many people with arthrogryposis will walk, while some will need a wheelchair. Regardless of whether they walk or use wheels, it’s all about effective mobility. Those who walk may need braces (AFO’s, KAFO’s or HKAFO’s) or walking aides (walkers or crutches). There are two types of wheelchairs people with AMC may use depending on how they’re affected, manual chairs (which are propelled with the arms) or power chairs (which are propelled by a motor).

There is no cure and even fabulous treatment can’t regain normal range of motion and strength in every joint BUT Its AMAZING what people with Arthrogryposis figure out how to do despite “crooked” limbs! People with AMC kind of make range of motion and normal muscle mass look over rated. Think about this….could you make a fruit salad *without* using your hands!?

Arthrogryposis can cause height and weight deficits in childhood and subsequently in adulthood. Children with AMC tend to be on the low end of the growth charts for weight (or not on the chart at all). As adults they tend to be 4-8 inches shorter than familial height and weigh 10-20 lbs less than their peers. Obesity should be avoided because it makes it harder to move limbs that are already weaker (taken from page 24 of the AMC Text Atlas)

Lack of movement during fetal life causes the joint contractures in arthrogryposis but another sign that there was lack of movement is lack of creases over the joints. Look at the skin over your joints when they’re straight, there are creases visible, a lot of babies with AMC lack these in the joints their affected in.

Despite the fact that Arthrogryposis is not curable kids with arthrogryposis grow up to be success and independent adults. Some people will be able to care for themselves unaided, while Some people will need aides to come in and help with some daily tasks. Some professions adults with AMC have chosen include, doctors, lawyers, dentists, engineers, teachers, artists, business owners, professors, chemists, personal trainers, social workers, authors, musicians, journalists and more!

Adults with arthrogryposis are prone to developing osteoarthritis, some earlier in life than their typical peers. It’s not known exactly why arthritis develops in adults with AMC, it’s either because of abnormal joint surfaces (due to the contractures) or its because of the vigorous PT early in life that’s necessary to increase joint mobility. Some adults will need joint replacements to relieve the pain of the arthritis. (adapted from the AMC Text Atlas).

Arthrogryposis is not considered progressive; it’s as severe as it’s going to get at birth, and the contractures won’t worsen with time. It is however regressive in nature. This means that even after any type of treatment (even highly effective treatment whether it be surgical or non-surgical) the contractures/ deformity can re-occur. So a foot can go back into a clubbed position, a knee can get stuck in a flexed position again, a wrist can stop going to neutral again ect, this is also called relapse. Post-treatment bracing (like after casting or surgery) is very important to try to prevent relapse but even strict brace wear doesn’t stop all relapses. Once a person stops growing the contractures are less likely to re-occur.

Most kids and adults who have a diagnosis of arthrogryposis are cognitively typical, meaning their IQ scores are normal or above normal. Some people with AMC will have some level of mental impairment that affects their IQ score.

Amyoplasia, one of the most common types of Arthrogryposis, can occur in identical twins but only 1 baby is affected and one is typical. This is one of the reasons that amyoplasia is not considered genetic. AMC can happen in just 1 twin of a fraternal set and AMC can happen in both twins if the AMC is genetic in nature.

Arthrogryposis is not a newly identified condition. Adolph Otto officially described it in 1841. There is also evidence of it in literature as early as the 12th century (perhaps earlier) and it’s likely that the beggar in the 1642 painting, “the clubfoot”, (which hangs in the Louvre) has some form of AMC (the text atlas says amyoplasia, another article says distal).

Arthrogryposis is not a widely studied condition but Dr. Judith Hall, a clinical geneticist, has been studying AMC for 40 years and has advanced the medical community’s understanding of joint contractures in a newborn. In her talk at the 2012 AMC conference she reiterated that arthrogryposis is a symptom of an underlying condition/ syndrome. Her dedication to the AMC community is astonishing. She stayed at conference for 2.5 days and met with families all day long, giving them answers no one else could. As a community we are forever indebted to her for the advancements in understanding the causes of AMC.

Hall said at conference that it used to be believed that all cases of lower extremity only arthrogryposis were amyoplasia type but that now its known that a whole list (she showed the list) of conditions and syndromes can cause contractures in the legs only.

According to Dr. Fisher from OrthoIndy (who spoke at conference) there is very, very little information in the medical literature on joint replacements in adults with AMC and degenerative arthritis. Dr. Fishers experiences in replacing joints affected by AMC in 2 of his patients have been positive and he is publishing an article soon about one of his patients! Like with all things AMC related, there needs to be more research on aging with joint contractors!

A lot more is known about arthrogryposis now compared to 40 years ago when Dr. Hall started her research but we need to push for even more research. The cause of amyoplasia needs to be discovered, the genes in some genetic types need to be identified, there needs to more research into more/different treatment options, there needs to be more information available about the long-term results/ affects of current treatment and there needs to be more research on aging with arthrogryposis.