Congenital Pseudarthrosis of Clavicle

A rare syndrome with most often right-sided clavicular pseudarthrosis.

More than 200 cases have been reported worldwide. Most likely autosomal dominant inheritance, although the majority of cases (approximately two thirds) seem to occur sporadically.

Commonly, the disorder is characterized by a painless, prominent lump or spike under the skin causing some discomfort with activity combined with short stature, high arched palate, and irregular upper teeth. Vascular thoracic outlet syndrome has been described in a small number of patients. Radiography shows a pseudoarthrosis in the middle third of the clavicle, closer to the junction with the lateral third. The two segments are not in continuity, the ends are enlarged, and no callus or reactive bone formation can be seen. The lesion manifests almost always on the right side (fewer than 10 left-sided cases have been reported, almost all of which were associated with dextrocardia; in 10% the lesion occurs bilaterally), leading to speculations that excessive pressure from the right subclavian artery, normally at a higher level on the right, causes the pathology. Other researchers hypothesized that the anomaly results from failed coalescence of the two primary ossification centers of the clavicle. Differential diagnosis includes Cleidocranial Dysostosis and posttraumatic pseudarthrosis. Treatment is either conservative or surgical.

The airway should be assessed for difficult management because of the maxillary anomalies. In cases with suspected or known difficult intubation, spontaneous ventilation should be maintained until the airway has been secured. Central venous access via the subclavian route on the affected side probably should be avoided because access may be distorted and therefore difficult.

Cleidocranial Dysplasia: Generalized skeletal dysplasia resulting in defects in the development of the skull, clavicles and pelvis, and dental abnormalities.

Craniofrontonasal Dysplasia: An X-linked syndrome, strangely more severe in females, combining frontonasal dysplasia, coronal craniosynastosis, various other skeletal and soft tissue abnormalities (including clavicular pseudarthrosis) and mental retardation.