Bilateral congenital radioulnar synostosis

Case contributed by Dr Matt Skalski

Presentation

Limited forearm range of motion in supination/pronation

Patient Data

Age: Child

There is moderate anterior bowing of the radius bilaterally, with osseous continuity between the proximal radii and ulnae. This fusion involves the entirety of both radial heads, and fixes the forearms in a pronated position. 

This illustration demonstrates the functional difficulties that occur when the forearm is fixed in a pronated position as a result of radioulnar synostosis. 

Case Discussion

Congenital radioulnar synostosis is the most common congenital functional disorder of the elbow. It demonstrates an autosomal dominant pattern of inheritance with no sex predilection, and is bilateral in 60-80% of cases. Approximately 400 cases of congenital radioulnar synostosis have been documented in the worldwide literature, and the average age at diagnosis is 6 years.

Four types of congenital synostosis are described, as follows: 

  • type I - fibrous synostosis, does not involve bone, and is associated with a normal, articulating radial head. 
  • type II - osseous synostosis, associated with a normal, articulating radial head. 
  • type III - osseous synostosis, with a hypoplastic and posteriorly dislocated radial head. 
  • type IV - short osseous synostosis with an anteriorly dislocated, mushroom shaped radial head.
PlayAdd to Share

Case information

rID: 24395
Case created: 12th Aug 2013
Last edited: 20th Sep 2013
Inclusion in quiz mode: Included

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.