Arthrogryposis

Arthrogryposis Multiplex Congenita is a Greek term for “curved joint.” Children diagnosed with arthrogryposis are born with a limited range of joint motion. Other than joint stiffness and muscle weakness, most children who have arthrogryposis are medically healthy.

Arthrogryposis occurs in about one of every 3,000 births. A diagnosis of arthrogryposis requires the following three characteristics:

• Congenital – a child as the condition at birth
• Non-progressive – the condition does not worsen as a child ages
• Includes multiple joint contractures – the motion of two or more joints is limited

Types of arthrogryposis

• Distal arthrogryposis – affects only a few joints, usually in the hands and feet. Range of motion might be mildly limited.
• Classic arthrogryposis – affects the hands, wrists, elbows, shoulders, hips, feet and knees to varying degrees. In the most severe cases, nearly every body joint can be involved, including the jaw and the back. Joint contractures are frequently accompanied by muscle weakness, further limiting movement.
• Syndromic arthrogryposis – affects internal organs as well as the muscle and joint system. Internal organ involvement can include breathing problems, feeding problems, speech disorders and sometimes mental retardation.

Causes

Anything that prevents normal joint movement before birth can result in joint contractures. When a joint isn’t moved while the baby is in the uterus, extra connective tissue grows to fix it in position. Lack of joint movement also means that tendons connecting to the joint aren’t stretched to their normal length. Short tendons make normal joint movement difficult.

Factors that can limit joint movement before birth include:

• Improperly or incorrectly developed muscles
• Lack of room in the uterus for normal movement
• Malformation of the central nervous system and spinal cord
• Abnormal development of the muscles, tendons, bones, joints or joint
• Heredity – the condition is passed from parent to child

Treatment

Physical therapy can help improve muscle strength and range of motion of affected joints for most types of arthrogryposis. Removable splints enhance the effectiveness of stretching exercises. In addition, surgery is sometimes an option. Surgery on the ankles can improve the foot position, making it easier for a child to bear weight and walk. Though performed less frequently, surgery on the knees, hips, elbows and wrists helps achieve greater range of motion. In some cases, tendon transfers are performed to improve muscle function.