Pediatric Arthrogryposis

What Is Arthrogryposis?

Arthrogryposis describes a group of congenital disorders that cause joint and muscle deformities. Babies with arthrogryposis are born with contracted, stiff joints and underdeveloped muscles. Although arthrogryposis does not worsen over time, it can cause further joint deformities if untreated.

What Causes Arthrogryposis?

Several conditions involving lack of movement during fetal development may cause arthrogryposis, including:

• Abnormal muscle development
• Problems in the development of the nervous system and spinal cord
• Overgrowth of connective tissue around joints
• Improper growth of tendons, joints, and bones

Inherited genetic mutations can cause some types of arthrogryposis, as can certain maternal problems during pregnancy:

• Limited space for the fetus to move, caused by an abnormally shaped uterus or amniotic fluid leakage
• Illnesses including multiple sclerosis, diabetes, and myasthenia gravis (an autoimmune disease affecting nerves that control voluntary muscles)
• Infections such as measles and high fever (more than 102 degrees Fahrenheit/39 Celsius)

Types of Arthrogryposis

Arthrogryposis may develop in different parts of the body. The two most common types occur in the limbs:

• Amyoplasia (most common) in the arms and legs
• Distal arthrogryposis in the hands and feet

Symptoms of Arthrogryposis

Many symptoms of arthrogryposis are apparent at or before birth. Signs vary depending on the type of arthrogryposis and include:

• Rigid, contracted, or dislocated joints
• Delayed walking, until 2 to 5 years of age
• Underdeveloped or absent muscles
• Similar deformities on both sides of the body
• Foot deformities, especially clubfoot
• Permanently flexed or overlapping fingers
• Abnormally short stature or dwarfism
• Cleft palate
• Scoliosis (curvature of the spine)

How Is Arthrogryposis Diagnosed?

The pediatrician will discuss your family’s medical history and may request some tests, including:

• X-rays to check bones and joints
• Diagnostic imaging, including computerized tomography, magnetic resonance imaging, and ultrasound scans, to examine the nervous system, organs, bones, and muscles
• A biopsy of muscle tissue to see whether muscle fibers are normal
• A skin biopsy or blood tests to evaluate chromosomes for any problems
• Electromyogram and nerve conduction velocity (EMG/NCV) tests to evaluate function in nerves that control voluntary muscle movement
• Genetic testing for conditions affecting voluntary muscles such as muscular dystrophy and spinal muscular atrophy

Your physician can also detect joint problems and diagnose arthrogryposis before your baby is born through prenatal ultrasound of your uterus (womb).

Treatments for Arthrogryposis

At Children’s National, we focus on helping your child develop flexibility and strength. Among the treatments we recommend are:

• Physical therapy to improve your child’s muscle strength and joint motion
• Occupational therapy to help build self-care and mobility skills such as eating, getting dressed, and walking
• Splints and braces to improve range of motion by properly aligning bones and keeping joints stretched
• Surgery to adjust bones, muscles, and tendons or to correct conditions such as scoliosis and clubfoot

Learn more about our Spine Program and Orthopaedics and Sports Medicine at Children’s National.