Arthrogryposis is a birth defect that causes decreased range of motion of two or more joints that causes them to be fixed in one position. This can affect any joint in the body. Examples include clenched fingers that cannot open or a foot that is turned inward and cannot straighten. Causes of arthrogryoposis include problems with the muscles or nerves and limited fetal movement inside the womb caused by too many fibroids, very low amniotic fluid, or multiple fetuses in one pregnancy, like twins, triplets, and quadruplets.
It affects 1 in 3000 babies.
When arthrogryposis is diagnosed, a thorough ultrasound of the fetal body is performed to look for other defects. Sometimes, arthrogryposis can be due to genetic causes so an amniocentesis is recommended. Fetuses with this condition may have severely poor lung development, and as a result do not survive long after birth. If this is strongly suspected, termination of the pregnancy may be an option. There is no available treatment while the fetus is in utero. Often, during delivery, affected fetuses will be in breech (feet first) position and will need to be delivered via C-section.
Once the infant is born, pediatricians will assess his/her breathing and perform a physical exam. An X-RAY or MRI may be performed. In most cases, a cast will be placed on the defect and, if needed, major corrective surgery performed between 3 and 12 months of age. These children all require intense physical therapy to improve their strength and flexibility. The prognosis depends on whether the infant has any difficulty breathing. Most infants with arthrogryposis do well long-term, although they will have limited function in the affected joints.