Congenital multiple arthrogryposis

Arthrogryposis multiplex congenita is characterized by multiple joint contractures (especially of the upper limbs and neck) and amyoplasia, usually without other major congenital anomalies. Intelligence is relatively normal.

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What causes arthrogryposis multiplex congenita?

Any condition that impairs fetal movement during the fetal period (eg, uterine malformations, multiple gestation, oligohydramnios) may result in arthrogryposis multiplex congenita (AMC). AMC is not a genetic disorder, although some genetic disorders (eg, spinal muscular atrophy type I, trisomy 18) increase the risk of arthrogryposis. AMC may be due to neurogenic disorders, myopathies, or connective tissue disorders. Congenital myopathies, anterior horn neuronal disease, and maternal myasthenia gravis are thought to be causes of associated amyoplasia.

Symptoms of Arthrogryposis Multiplex Congenita

Deformities are evident at birth. Congenital arthrogryposis multiplex is not progressive; however, the underlying cause (eg, muscular dystrophy) may be. Flexion or extension contractures are formed in the affected joints. The shoulders are usually adducted and in internal rotation, the elbows are extended, and the wrists and fingers are flexed. The hips may be dislocated, and the legs are usually slightly flexed at the hips. The knees are extended; equinovarus feet are common. The leg muscles are usually hypoplastic, and the limbs tend to be cylindrical and completely straight. There is sometimes thinning, webbing of the soft tissues on the ventral side of the joints, with flexion contractures. Scoliosis may be present. Except for thinning of the long bones, the skeleton appears normal radiographically. Physical impairments may be severe and disabling. Intelligence is usually normal or slightly reduced.

Other anomalies that rarely accompany arthrogryposis include microcephaly, cleft palate, cryptorchidism, cardiac and urinary tract defects.

Diagnosis of congenital arthrogryposis multiplex

The examination should include a thorough search for associated abnormalities. Electromyography and muscle biopsy can be used to diagnose neuropathies and myopathies. Muscle biopsy usually reveals amyoplasia with fatty and fibrous tissue replacement.

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Treatment of congenital arthrogryposis multiplex

Arthrogryposis multiplex congenita requires early referral to an orthopedist and physical therapist. Exercises and physical therapy of the joints during the first months of life can lead to significant improvement. Orthotic devices may be effective. Surgery may be needed later to reduce ankylosis, but improvement in range of motion is rare. Muscle repositioning (eg, surgically repositioning the triceps so that it can bend the arm at the elbow) may improve function. Many children do well; 2/3 are ambulatory after treatment.