Arthrogryposis multiplex congenita includes a group of disorders characterized by multiple congenital joint contractures. The causes of fetal akinesis include disorders of nerves, muscles, or connective tissues, maternal disease, intrauterine constraint, or vascular compromise. The earlier and longer this loss of movement, the more severe the deformities. The most common deformities include clubfeet and hip dislocations. Most deformities are nonprogressive.
Evaluation and differentiation
A differentiation may be complex, and in some instances the exact diagnosis cannot be established. Deformities may be classified based on whether they primarily affect the limbs, include systemic involvement, or have a clear neurological etiology. Certain types are most likely to be seen by the orthopedist.
Amyoplasia is the classic form of arthrogryposis, making up about a third of the cases. The common features include clubfeet, flexed knees, dislocated hips, internally rotated and abducted shoulders, flexed or extended elbows, pronated forearms, and flexed wrists. The trunk is less commonly affected. Muscles are hypoplastic or absent, joints are fibrotic and stiff. Joints show a loss of creases and dimpling. IQ is normal, sensation is intact, potential for walking is good, and most become independent and productive in adult life.
Distal arthrogryposis includes six subtypes, often inherited and primarily involving the hands and feet. DNA blood testing is available. Fingers are flexed, medially deviated, and overlapping, and fist is clenched. Clubfeet or vertical tali are common.
Contractual arachnodactyly is an autosomal-dominant disorder with long extremities, joint contractures, and ear crumpling.
Pterygium syndromes include a group of varied disorders with characteristic features.
Freeman–Sheldon syndrome, or whistling face syndrome, is a familial disorder with a characteristic puckered appearance to the face and multiple joint contractures.
Diastrophic dysplasia is a syndrome that includes short stature, multiple contractures.
Treatment of Arthrogryposis
Management principles may be applied to most of the patients.
Accurate diagnosis is necessary to advise the family about the recurrence.
Family counseling Deal with family guilt, which is usually present and unless resolved will interfere with management. Provide information regarding local or national arthrogryposis support groups. For parents of infants with amyoplasia, provide information regarding the favorable natural history with progressive reductions in deformity and the potential for an independent and productive life.
Physical therapy should be started early to reduce contractures and facilitate bonding. Encourage the family to provide the treatment. This is most convenient and economical for the family, and the parent-child interaction is emotionally therapeutic. Stretching should be gentle and atraumatic.
Bracing facilitates function by providing joint stabilization for standing and walking. Lightweight nonarticulated plastic AFO or KFO are most useful. Allow bracefree periods during the day for the child to crawl. Splinting at night is often essential to prevent recurrence of deformity once corrected by surgery.
Adaptive equipment such as walkers, electric wheelchairs, and devices to facilitate self-care are very valuable.
Operative correction is necessary to correct clubfeet, knee contractures, or hip dislocations. Minimize the duration of immobilization during infancy and childhood by combining procedures, minimal duration of postoperative immobilization, and avoiding repeated procedures. Delay operative correction of upper-extremity deformities until early childhood, when disability is clear. Surgery is necessary only to enhance function and not to correct deformity per se.
Manage by early stretching, casting, percutaneous releases, and repeated casting. Correct residual deformity by extensive posteromedial release or talectomy. Provide night splinting for several years following correction to prevent recurrence. If recurrence does occur, correct with serial casting and reinstitute night splinting. Provide stretching exercises during the day. Avoid repeated procedures.
Knee Flexion–Extension Deformity
Manage by early stretching to correct less fixed deformity. Correct fixed deformity by hamstring lengthening, capsulectomy, and femoral shortening, if necessary. Correct hyperextension deformity by quadriceps lengthening to center arc of motion to 15° of flexion.
Reduce dislocations in infancy by an open reduction, and shorten postoperative immobilization to about 5 weeks. Combine with other procedures when possible. Avoid repeated or extensive procedures that may cause stiffness. Establish symmetry and maintain mobility.
Provide early manipulation to improve motion and retain with night splints. Teach use of adaptive devices to facilitate self-care. In early childhood, perform procedures to correct deformity that interferes with function. Because of good hand sensibility, function is often surprisingly good.