The coracoclavicular joint.

The coracoclavicular joints are genetically determined anatomic variants. There are problems in determining their presence by dissection examination of osteologic material as well as by radiography. Based on a survey of published material and a prospective radiological survey carried out in Malaysia, it is clear that the anomaly is more frequent in Asia than in Europe and Africa. There is a high incidence in people from Southern China. The joints are subject to osteophytic marginal lipping without development of symptoms or disability.