Congenital arthrogryposis, also known as arthrogryposis multiplex congenita (AMC), describes a group of conditions characterized by multiple joint contractures present at birth. These contractures cause stiffness and limited movement in two or more areas of the body, affecting a baby’s ability to fully extend or bend their joints. It encompasses over 300 different disorders.
Understanding Congenital Arthrogryposis
The primary characteristic of congenital arthrogryposis is joint contractures, where joints become permanently fixed in a bent or straightened position. This stiffness restricts the range of motion in affected joints, leading to muscle weakness or underdevelopment. The condition can manifest with varying degrees of severity, from mild involvement of a few joints to severe cases affecting nearly every joint in the body, including the jaw and spine.
Commonly affected joints include the hands, wrists, elbows, shoulders, hips, knees, and feet. Babies might present with sloped shoulders, extended elbows, curled wrists and fingers, dislocated hips, extended knees, or feet pointed downward and inward, often resembling clubfoot. Congenital arthrogryposis is not a progressive disorder, meaning contractures do not worsen over time, though associated spinal deformities may develop during childhood or adolescence.
What Causes Congenital Arthrogryposis
The causes of congenital arthrogryposis are diverse and often multifactorial, involving a combination of genetic and environmental influences. A primary factor is anything that inhibits normal fetal movement before birth, as movement is necessary for proper joint development. This reduced fetal movement, known as fetal akinesia, can lead to extra connective tissue around the joints, causing stiffness.
Genetic factors play a role, with over 400 altered genes identified that can affect arthrogryposis, and it is linked to more than 35 genetic disorders. These genetic causes can include issues with nerves (neuropathic), muscles (myopathic), or connective tissue disorders. Environmental factors can also contribute, such as insufficient room in the uterus, low amniotic fluid, or an unusually shaped uterus, maternal infections, certain drugs, or trauma during pregnancy. Despite these identified factors, in many instances, the precise cause of congenital arthrogryposis remains unknown.
Identifying Congenital Arthrogryposis
Congenital arthrogryposis can sometimes be detected before birth through prenatal ultrasound, which may reveal decreased fetal movement or abnormal joint positions. Common ultrasound findings include clubfoot, clenched hands, or contractures in the elbows and knees. After birth, diagnosis is primarily made through a physical examination, where a healthcare provider observes multiple joint contractures in different body areas.
Imaging studies like X-rays or MRI scans are often used to assess the extent and type of joint involvement, providing a clearer picture of the musculoskeletal deformities. Genetic testing may also be recommended to identify specific gene mutations or underlying genetic syndromes, which can help determine the prognosis and guide genetic counseling for families. A comprehensive evaluation aims to differentiate arthrogryposis from other conditions and establish a specific diagnosis.
Managing Congenital Arthrogryposis
Managing congenital arthrogryposis involves a comprehensive, multidisciplinary approach focused on maximizing joint mobility and functional independence. Early intervention is highly beneficial, beginning soon after birth. Physical therapy is a cornerstone of treatment, utilizing gentle stretching exercises, joint mobilization techniques, and strengthening exercises to improve muscle strength and stability.
Occupational therapy complements physical therapy by focusing on enhancing daily living skills and functional abilities, such as bathing, dressing, and feeding. Therapists may incorporate adaptive techniques and assistive devices to promote independence. Serial casting and splinting are frequently employed to gradually stretch contracted joints and maintain improved range of motion. Surgical interventions, such as tendon releases or osteotomies, may be considered to correct severe contractures or improve joint alignment when conservative methods are insufficient.
Living with Congenital Arthrogryposis
The long-term outlook for individuals with congenital arthrogryposis is generally positive, with many achieving significant functional improvements and leading independent, fulfilling lives. Since the condition is non-progressive, its effects do not worsen over time. Consistent engagement in therapy helps individuals maintain and enhance their mobility and strength.
Outcomes can vary based on the severity and specific type of arthrogryposis, but a substantial number of individuals learn to walk, sometimes with the aid of braces or crutches, or utilize wheelchairs for mobility. A long-term study of adults with arthrogryposis showed that many pursued higher education, married, and had children, with a majority achieving self-sufficiency. Support systems, including family and healthcare professionals, play an important role in living with this condition.