Table of Contents
What is Arthrogryposis and Definition
The collective term for a group of congenital disorders, also called arthrogryposis multiplex congenita, in which multiple contractures restrict joint function throughout the body. Joints may be partially or completely fused. Researchers believe about 30 percent of arthrogryposis develops when the fetus is not able to move freely in the uterus before birth.
The restricted movement causes muscles and connective tissues such as tendons and ligaments to grow abnormally around the immobile joints, fixing them in their positions. Circumstances that may restrict fetal movement include
- Insufficient amniotic fluid
- Abnormalities of the uterus
- Large uterine fibroids
- Twins or other multiples
- Neurologic and other developmental anomalies in the fetus, such as muscular dystrophy or mitochondrial disorders, that inhibit normal movement
Symptoms Diagnostic Path
The doctor may suspect arthrogryposis when the pregnant mother reports that the movements of her unborn baby are infrequent. Ultrasound can detect the changes in soft tissue structure and bone fusions at the joints before birth; the joint deformities are obvious at birth. The delivery of an infant who has arthrogryposis may be challenging when the affected joints prevent normal passage through the birth canal.
The obstetrician may recommend cesarean section to avoid injury to infant and mother
Ultrasound after birth may provide additional information about the extent to which contractures affect the infant’s joints as well as help doctors determine whether there are other anomalies present.
Treatment Options and Outlook
Treatment depends on the extent of the contractures though typically combines surgery to correct joint deformities and casting with aggressive physical therapy to restore as much function as possible. Surgery can relieve the abnormal tension shortened connective tissue and muscle structures place on the joints, and the surgeon often can reconstruct more functional alignments to improve movement of the joint.
Surgery may also restructure bone tissue, generally in multiple operations timed with growth patterns throughout childhood. Physical therapy helps strengthen the tissues and extend range of motion.
Although the deformities are permanent, they are not progressive; thus the condition does not worsen as the child grows. Aggressive treatment early in life may allow a relatively normal lifestyle in late childhood and adulthood when contractures are mild to moderate. Severe contractures tend to result in permanent disabilities that require adaptive techniques and devices for mobility.
Risk Factors and Preventive Measures
Inability of the fetus to move freely in the uterus is the primary risk factor for arthrogryposis. Pregnancies in women who have neuromuscular disorders such as myasthenia gravis, multiple sclerosis, or myotonia are at higher risk.
Extended high fever during pregnancy, such as may occur with serious infection, may affect the development of the fetus in ways that impair muscle, connective tissue, and nerve structure and function. These impairments secondarily affect joint function.
About 30 percent of arthrogryposis is hereditary, though affected parents may have such mild symptoms that they do not know they have the condition
When one or both parents have arthrogryposis, there is increased risk the infant will also have the condition. Genetic testing and genetic counseling may help such parents evaluate their risk and make family planning decisions.
Page last reviewed: