Fused Rib or Rib Synostosis

History: 50 year old man with chest pain and shortness of breath.

Rib Synostosis (or fused rib): Frontal radiograph of the chest shows synostosis of the anterior right 4th and 5th ribs.

This is the appearance of a fused rib, or rib synostosis. Typically fused ribs are either congenitally fused or can become fused as a result of remote traumatic injury to the region of the fused ribs. Rib synostoses are relatively common, present in about 3% of the population, and they typically present with a chest wall “mass.” When congenitally fused, they can be associate with scoliosis as well as thoracic insufficiency syndrome. A retrospective review of fused ribs and chest wall anomalies and their association with congenital spine anomalies can be found here.

This is an posterior-to-anterior X-ray of a case of adolescent idiopathic scoliosis – specifically, my spine. There is a thoracic curve of 30° and a lumbar curve of 53° (Cobb angle – see scoliosis). This was taken at the Royal National Orthopaedic Hospital. The largest curve (53°) is of a magnitude typically near the lower surgery boundary, although many factors decide whether surgery is necessary on a scoliosis case. (Photo credit: Wikipedia)