Amyoplasia and distal arthrogryposis

Arthrogryposis multiplex congenita (AMC) consists of congenital joint contractures that affect at least two joints. There are two types: in the first, arthrogryposis is an additional sign in the context of various pathologies (neuromuscular diseases); in the second, it is the main and constant symptom. In the first type, the progression of the causal underlying disease must be considered. In the second type, there are two specific forms: Amyoplasia corresponds to a significant congenital absence of muscles (epigenetic disease or vascular origin) while distal arthrogryposis has a genetic component and is transmissible. The orthopedic surgeon's purpose, which is usually to enhance movement, is not appropriate for an arthrogryposis patient. One must keep in mind that without muscle, movement is impossible. The goal differs between the upper and lower limbs: for the upper limb, it is to allow grasping, and, if possible, to bring the hand to the mouth; for the lower limb, it is to ensure ambulation with plantigrade support, and the knees extended, which is the only stable position possible with little to no muscles. The rehabilitation, orthoses and/or surgical techniques are chosen to achieve this singular aim. While it may appear modest, it is crucial for patients. The goal is to achieve useful mobility, not maximum mobility. This multidisciplinary treatment, which evolves over time, must be explained to the family to get its adherence.