There are two bones in the forearm: the radius and ulna (Figure 1).
The movements of forearm rotations (supination and pronation) occur as the radius rotates around the ulna (Figure 2).
Congenital synostosis of the radius and ulna is a condition in which the two bones instead of being separate and are joined to each other at their upper end. Due to this, the forearm rotation movements are absent and the forearm is fixed in a particular position (Figure 3).
The child may have difficulty in performing hand-to-mouth activities which require forearm supination. e.g. eating, wiping the face, combing hair, etc.
Plain X-rays are sufficient for the diagnosis of congenital radius ulna synostosis and show a bony bridge between the proximal radius and ulna
Treatment of congenital radius ulna synostosis depends on the position in which the forearm is locked and functional difficulties.
Many children have no restriction of activities. Such children do not need any treatment.
If the child has significant functional limitations, surgery can be performed to improve forearm position. This surgery is called radius-ulna de-rotation osteotomy.
In this surgery, the radius and ulna bones are cut and the forearm is de-rotated to a more functional position so that performing hand-to-mouth activities becomes easier.
-DR SANDEEP VAIDYA,
This article is contributed by Dr Sandeep Vaidya, Paediatric Orthopaedic Surgeon, Pinnacle Orthocentre Hospital, Thane. Dr Vaidya is also available for consultations at BJ Wadia Children’s Hospital, Mumbai; Ajit Scan Centre, Kalyan; and Ace Children’s Hospital, Dombivli. For more information, call 7028859555/ 8879970811/ (022)25419000/ 25429000 OR email email@example.com.