Director: Shade Moody, MD

What causes arthrogryposis?

Children with arthrogryposis share a common prenatal history – all are unable to move sufficiently within the uterus prior to birth. While their joints are constrained in utero, extra protective fatty and fibrous tissue grows around the joints, fixing them in position. This increase in tissue around the joints replaces muscle, causing weakness and giving an appearance of “wasting.” Lack of joint movement in the womb also prohibits the tendons that connect the joints from being stretched to their normal length. Short tendons make joint movement difficult.

Conditions leading to arthrogryposis

While children with arthrogryposis all share a common lack of prenatal movement, the reasons for their restricted movement vary.

Lack of joint movement in utero, known as fetal akinesia, occurs for a number of reasons including but not limited to:

  • Muscles fail to develop properly due to muscle disease (for example, congenital muscular dystrophy), maternal fever during pregnancy, or a viral infection which may damage cells that transmit nerve impulses to muscles.
  • Other abnormalities of the peripheral nervous system.
  • The uterus does not allow sufficient room for fetal movement, often due to lack of amniotic fluid or an abnormally shaped or positioned uterus.
  • The central nervous system and spinal cord are malformed. In these cases, arthrogryposis usually is accompanied by a wide range of other conditions. Tendons, bones, joints or joint linings may develop abnormally. For example, tendons may not be connected to the proper place in a joint.

By and large, arthrogryposis is not genetic. It occurs once in a family and never recurs. Thirty percent of cases, however, are genetic in origin, and families affected require genetic counseling.

Clinics are held every other 1st Thursday of the month at Shriners Hospital for Children.
For appointments call 713.797.1616.