ARTROGRYPOSIS MULTIPLEX CONGENITA

Arthrogryposis multiplex congenita is a non progressive congenital syndrome characterized by poorly developed and contracted muscles, deformed joints with thickened periarticular capsule and intact sensory system.

• Etiology:
  Congenital or acquired defect in the motor unit (anterior horn cells, nerve roots, peripheral nerves, motor end plates or muscles). The classic form (amyoplasia), is sporadic in occurrence.
  The condition is more frequent amongst monozygotic twins and is almost always discordant.
• Histology
  Absent of limb musculature with replacement by fibrous and fatty tissue.

ULTRASOUND (1-4)

• Distribution:
• All extremities (46%).
• Lower extremities only (43%).
• Upper extremities only (11%).
• Symmetrical.
• Peripheral joints more frequently than proximal joints.
• Flexion and extensions deformities and talipes.
• Flexion deformities of the wrist and elbows.
• Flexion or extension of the knees.
• Claw hand.
• Clubfoot.
• Congenital hip dislocation.
• Skin webs.
• Decreased muscle mass.
• Congenital vertical talus or calcaneal valgus deformity.
• Micrognathia (probably due to neuromuscular dysfunction).
• Polyhydramnios (usually late onset and presumable due to impaired swallowing).
• Increased nuchal translucency at 10-14 weeks (3).

REFERENCES

1. Hall JG, Reed SD, Driscoll EP. Amyoplasia: A common sporadic condition with congenital contractures. Am J Med Genet 1983;15:571.
2. Quinn CM, Wigglesworth JS, Heckmatt J. Lethal arthrogryposis multiplex congenita: a pathological study of 21 cases. Histopathology 1991;19:155-162.
3. Baty BJ, Chubberley D, Morris C et.al. Prenatal diagnosis of distal arthrogryposis. Am J Med Genet 1988;29:501-510.
4. Hyett J, Noble P, Sebire NJ et.al. Lethal congenital arthrogryposis presents with increased nuchal translucency at 10-14 weeks of gestation. Ultrasound Obstet Gynecol 1977;9:310-313.