Congenital Radioulnar Synostosis & Radial Head Dislocation

Also known as: radioulnar fusion, congenital radial head dislocation.

What is congenital radioulnar synostosis/radial head dislocation?

Congenital radioulnar synostosis is a condition in which there is an abnormal bony connection between the radius and the ulna, two forearm bones. A similar condition, congenital radial head dislocation, refers to dislocation of the radial head from the proximal radioulnar joint.

What causes congenital radioulnar synostosis?

The cause of congenital radioulnar synostosis is not entirely clear. It is thought to develop during fetal development.

What are the symptoms of congenital radioulnar synostosis?

The main symptom of congenital radioulnar synostosis is limitation of forearm rotation. The patient is unable to pronate or supinate the forearm. The forearm may be shorter or deformed, but this is unusual.  Pain is unusual. Oftentimes, increased mobility of the shoulder and wrist provide compensatory movement that may mask the fixed forearm deformity.

What are congenital radioulnar synostosis care options?

Therapy is sometimes used to assist patients in finding compensatory movements.  Surgical intervention is sometimes indicated, especially if the forearm is fixed in an unfavorable, functionally-limited position.

Reviewed by: Aaron J Berger, MD

This page was last updated on: September 16, 2025 12:29 PM