What is AMC?
Arthrogryposis or Arthrogryposis Multiplex Congenita (AMC) is a generic term used to describe a congenital non-progressive limitation of movement of two or more joints in different areas of the body. It occurs in utero as a result of restricted or limited joint movement during foetal development. It is a relatively rare condition that effects approximately 3 in every 10,000 births.
It is not a problem in the formation of the actual joint or limb, but rather it is a problem during foetal life (i.e., after 8 to 10 weeks of the pregnancy). The joint is likely to be normal, but lack of movement is associated with the development of extra connective tissue around the joint. This extra connective tissue fixes the joint in place and limits movement even more. As a result the tendons around the joint may not have stretched to their normal length, and this makes normal joint movement after birth more difficult.
(Referenced from: Arthrogryposis - A Text Atlas)
Types of AMC:
There are more than 200 conditions that come under the Athrogryposis umbrella’ and these can be divided into the following groups:
- disorders with mainly limb i.e. just the arms and legs.
- disorders with limb plus some other body area cleft palate, the heart, intestinal defects, curvature of the spine.
- disorders with limb and the central nervous system.
The most common types of AMC are:
The most common of all the AMC conditions is an overall lack of muscular development and growth with contracture, a loss of joint motion, and deformity of most joints. Babies diagnosed with amyoplasia have dense fibrous tissue and fat instead of skeletal muscle.
This type affects only several joints usually in the hands and feet, and range of motion may be mildly limited.
Usually affecting the hands, wrists, elbows, shoulders, hips, feet and knees in various degrees of severity. The most severe can affect almost every joint, including the back and jaw. Joint contractures, or loss of joint motion, are frequently accompanied by muscle weakness which contributes to the limited movement.
This type affects the internal organs as well as the muscle and joint systems. Internal organ involvement can include breathing problems, feeding problems, possible speech disorders and in some cases, mental retardation. Some factors that can limit joint movement before birth include:
- Improperly or incorrectly developed muscles
- Limited room in the uterus for normal movement
- Improper formation of the central nervous system and spinal cord
- Abnormal development of the muscles, tendons, bones or joints
- Genetic inheritance, the condition is passed from parent to child.
What is the impact of living with AMC?
Although people with AMC have certain challenges and in early life may need multiple corrective surgeries for long term comfort and physical ease, most individuals tend to go on and live full and independent lives just as well as their peers or other siblings, such as attending mainstream education, professional careers, marriage, travelling, parenting etc.
For some individuals that may require additional needs later in adulthood, such as the use of a PA, there is support available through the likes of the HSE or other institutions. This, from our experience to date, has not diminished the individual’s ability to live a full independent and meaning full life.
For more information on AMC, Support and information: