aetiology

Last reviewed 01/2018

The aetiology of arthrogryposis is unclear. There is thought to be a failure of differentiation of soft tissue and bony elements that is sporadic but due to a limitation of in utero fetal movements.

The reasons for a lack of in utero movements include:

  • oligohydramnios or other causes of restricted space within the uterus
  • primary nerve or muscle abnormalities; the neuropathic form is felt to be the most common type
  • viral infection
  • vascular insufficiency
  • toxins eg chronic cyanide exposure

Consequently, skeletal muscle fibres can atrophy. Putatively, there is then a secondary imbalance of forces on specific joints leading to contractures.