Introduction: Congenital pseudarthrosis of the clavicle is an extremely rar
e disease of unknown histogenesis. The method of treatment is still discuss
ed controversely. Cases: Two cases of a congenital pseudarthrosis of the ri
ght clavicle were presented, revealing the typical clinical, radiologic and
histopathologic features. Surgical treatment was performed at the age of 4
and 7 years, consisting of a partial resection of the bony ends of both se
gments of the clavicle, partial excision of the dense fibrous tissue lying
within the defective area in the middle third of the clavicles by forming a
continuous sleeve for interposing autogeneous spongiosa from the iliac cre
st and internal fixation with a Kirschner wire. Both cases showed a success
ful solid bone union in X-ray controlls after 8 weeks. Conclusions: Accordi
ng to the histopathological findings we assume an abnormal ineffective chon
dral instead of an endesmal ossification resulting from a damage during emb
ryogenesis as the underlying pathogenetic mechanism of congenital pseudarth
rosis of the clavicle. Since chondral ossification proves to be ineffective
also after birth, spontaneous bony union cannot be expected. Therefore, re
constructive surgery is the treatment of choice.