Amyoplasia Congenita

Rare congenital disorder constituting about one third of cases of Arthrogryposis Multiplex Congenita characterized by multiple contractures of joints.

Guérin-Stern Syndrome; Otto Syndrome; Rocher-Sheldon Syndrome; Rossi Syndrome; Congenital Arthromyodysplastic Syndrome; Myodysplasia Foetalis Deformans; Myodystrophia Foetalis Deformans.

Congenital disorder that may result from an intrauterine vascular accident affecting the fetal spinal cord.

Sporadic cases. Incidence is approximately 1:10,000 live births. Higher incidence is found in twins.

Unknown. Two forms have been described:

1. 1. Neuropathic form in which anterior horn cells are reduced in number, pyramidal tract and motor roots are demyelinated, and axons in peripheral nerves are reduced.

2. 2. Myopathic form in which joint deformities result from lack of movements in utero.

Based on clinical findings at birth in a child with contracture of numerous joints in a flexed position (arthrogryposis), hypoplasia of the attached musculature, and development of multiple pterygia in affected joints. In approximately two thirds of patients, all four limbs are affected; in approximately one fourth of patients, the lower extremities are more severely affected than the arms; and in the remaining cases, the arms are more severely affected than the lower extremities. The term amyoplasia refers to replacement of muscles by fibrous tissue in different areas.

Intelligence in these patients is normal. Common features involve the head and neck (low-set ears, ptosis, limited eye movements laterally and upward, abnormal retinal pigmentation, flattened nose, round facies, frontal midline capillary hemangioma, micrognathia, cleft palate), skeleton (scoliosis, dislocated hips, internally rotated and adducted shoulders, fixed extended elbows, wrist deformities consisting of flexion and ulnar deviation, talipes varus, syndactyly, camptodactyly, amputation of digits), gastrointestinal tract (gastroschisis, intestinal atresia, hypertrophic pyloric stenosis, gastric ulcers), and chest (hypoplastic lungs, diaphragmatic hernia, hydrothorax). Lymphedema has been observed.

Evaluate respiratory function (clinical, chest radiographs, pulmonary function tests if possible, arterial blood gases analysis, CT scans). Assess for difficult airway management (micrognathia, cleft palate).

Tracheal intubation may be difficult and may require adapted anesthetic management. Spontaneous ventilation should be maintained until the airway is secured. If significant, pleural effusions should be drained preoperatively. Postoperative mechanical ventilatory support may be necessary and should be arranged beforehand. Careful intraoperative positioning is mandatory and can be challenging secondary to limited joint mobility. Complications resulting from positioning, such as pressure sores and fractures, have been described. Venous access can be difficult with all the contractures. Avoid bag-mask ventilation in the presence of diaphragmatic hernia.

Muscle deficiency and respiratory function may require lower doses of muscle relaxants. Opioids should be used judiciously. No relation between malignant hyperthermia and arthrogryposis syndromes has been demonstrated. However, hyperpyrexia and hypermetabolism have been described in association with volatile anesthetics, although these reactions were thought to be distinct from malignant hyperthermia.

See Arthrogryposis Multiplex Congenita for a summary.