Sternocostoclavicular hyperostosis. Radiological and pathological study of a specimen with ununited clavicular fracture.

Anatomico-radiological study of a sternocostoclavicular mass taken post-mortem from a man whose clinical history had shown bilateral sternocostoclavicular hyperostosis (SCCH) with plantar pustulosis for 27 years. The clavicle showed an ununited fracture attributable to a trauma sustained five years earlier. Both clavicular segments showed active remodelling with intraosseous granulation tissue and periosteal metaplastic ossification. The sternocostoclavicular region was fused in a bony block in which there were no signs of remodelling activity. The first rib and the distal extremity of the clavicle were histologically normal. These observations support the conclusions of a previous study of another case of SCCH. The condition might be due to a bone infection caused by an--as yet--unknown germ. Bone remodelling would explain the periosteal hyperostosis and the fragility of the underlying bone. Furthermore, the possibility that the condition might also be a joint disease related to the group of rheumatic diseases called spondyloarthropathies should be considered.