Abstract
1. Thirteen cases of congenital pseudarthrosis of the clavicle conforming to the classical picture are presented, together with five cases of pseudarthrosis occurring for various other reasons, and nine cases of congenital pseudarthrosis that form a special group because there was a strong family history.
2. Treatment, if desired by the patient, is easy, but should be deferred until the age of four or five years.
3. The etiology remains obscure. Our embryological study does not support the theory that the clavicle normally develops from two ossification centres that may fail to coalesce. Although in thirteen of our patients there was no family history of pseudarthrosis, there was another group of nine patients who presented a strong family history, and it seems certain that in some instances congenital pseudarthrosis of the clavicle can be transmitted genetically.
