Webbed skin may also be present around affected joints, which further inhibits a person’s range
of motion (“Arthrogryposis”, Seattle Children’s Hospital).
Arthrogryposis is a nonprogressive condition, meaning that the condition does not worsen over
time. With regular rehabilitative treatment, range of motion in the joints and strength of muscles
around the joints may be improved significantly. People with arthrogryposis typically do not
have limited intelligence. People with arthrogryposis are typically able to live a full life, albeit
with a degree of assistance depending on the severity of their condition. Surgery to improve
range of motion is an option (Staheli, Hall, Jaffe, and Paholke 2).
Causes
Approximately one in 3,000 children are born with arthrogryposis. Fetal akinesia, decreased fetal
movement while in the womb, is the best known cause of arthrogryposis. Both extrinsic and
intrinsic factors contribute to the development of arthrogryposis due to fetal akinesia while the
child is in the womb (‘extrinsic’ refers to factors outside of the child while ‘intrinsic’ refers to
factors within the child). Extrinsic factors leading to fetal akinesia include a lack of room for the
child to develop in the uterus, an abnormally shaped uterus, maternal infection, trauma, or drugs
consumed by the mother. Intrinsic factors include a malformed spinal cord, malformed sections
of the brain, and disorders related to tendons, ligaments, bones, or joint lining. In rare cases,
genetics play a role in the occurrence of arthrogryposis (“Arthrogryposis”, Nationwide
Children’s Hospital).
Classification
The most common type of arthrogryposis is classified as amyoplasia; approximately onethird of
all cases of arthrogryposis are classified as amyoplasia. The most common classes of
arthrogryposis are listed below with characteristics.
● Amyoplasia: the shoulders are internally rotated, the elbows lack a full range of
motion. the fingers and wrists are stiff, and the hip may be dislocated. The
muscles are weakened severely.
● Distal Arthrogryposis Type 1: Characterized by clubfoot, joint contractures, and
permanently bent fingers. The shoulders and hips are rarely affected.
● Distal Arthrogryposis Type 2: Along with the contractures observed in Type 1,
Type 2 includes scoliosis and a smaller mouth and a dimpled chin. Type 2 is also
known as SheldonHall syndrome.
● Distal Arthrogryposis Type 5: Joint contractures with ocular abnormalities (a
child with Type 5 is shown in Figure 13).
Distal Arthrogryposis Types 3, 4, 6, and 7 are rare (Bamshad, Van Heest, and Pleasure 4046).
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