What is Congenital Radius Ulna Synostosis?

What is Congenital Radius Ulna Synostosis?

Our forearm bones have rotatory movements called supination and pronation. When our forearm is in supination, our palm faces upwards.When our forearm is in pronation, our palm faces downwards. These movements occur due to rotation of radius bone around the ulna .

Congenital Radius Ulna Synostosis is a congenital disorder where the radius and ulna bones in the forearm are fused or joined together from birth. Due to this, forearm rotations are restricted thereby causing various functional challenges.

Typically, children with this condition are inable to perform hand to mouth activities (Figures 1,2).

Figure 1: X-ray of a child with congenital radius ulna synostosis. Note that the bones of the forearm (radius and ulna) are joined to each other (red arrow). This leads to restriction of forearm rotation movements.

Figure 2: Clinical photograph of the child with congenital radius ulna synostosis. Note that both forearms are locked in pronation. This leads to difficulty in performing hand to mouth and other activities which need forearm supination.

What is the treatment of Congenital Radius Ulna Synostosis?

The treatment of Congenital Radius Ulna Synostosis depends on functional limitations faced by the child in day-to-day activities. If the child has no limitations in performing functions, child may just be observed and no treatment is needed.

Surgery is needed in more severe cases, when child has functional limitations. The surgery consists of derotating the forearm bones from position of extreme pronation to a more functional position of approximately 20 to 30 degrees supination (Figure 3).