Arthrogryposis Multiplex Congenital (AMC)

Arthrogryposis occurs when joints become permanently fixed in place – either bent or straight. This permanent position of a joint is known as a “contracture” and affects the movement of the joint.

What is Arthrogryposis Multiplex Congenital (AMC)?

Arthrogryposis can also be called arthrogryposis multiplex congenital (AMC). For the condition to be diagnosed, two or more areas of the body must be affected, and the condition must be present at birth (congenital). When only one joint is affected, such as club feet, the condition is known as an isolated congenital contracture.

Joints further from the center of the body are most commonly affected, including the arms and especially the legs. Shoulders and hips are not often affected. In some children, the condition is barely noticeable. In others, it is more severe. The contractures do not worsen over time, so treatments to encourage joint movement can lead to significant improvements. Arthrogryposis doesn’t affect a child’s cognitive abilities or limit their lifespan.

What are the signs and symptoms of Arthrogryposis Multiplex Congenital (AMC)?

  • Abnormalities of the central nervous system
  • Abnormally slender and fragile long bones of the arms and legs
  • Cleft palate
  • Undescended testes (in males)

What are the causes of Arthrogryposis Multiplex Congenital (AMC)?

More than 400 diseases can cause isolated or multiple contractures. Some of the causes of arthrogryposis are genetic. Others are due to the conditions in the mother’s womb.

The most common cause of arthrogryposis is decreased movement in the womb. Motion is critical for joints to develop properly, so when the baby doesn’t move as often as it should, joints can become fixed in place.

Arthrogryposis can occur because of:

  • Connective tissue disorders in the baby
  • Limited space while developing in the mother’s womb
  • Low amniotic fluid level
  • Maternal illness
  • Muscle or neurological problems

Other conditions associated with arthrogryposis include: