A bony outgrowth is seen from the distal shaft of humerus on the anteromedial aspect. It is directed towards joint (as compared to an exostosis which is directed away from the joint).

It represents a supracondylar spur, which is believed to represent a phylogenetic vestige of the supracondyloid foramen found in reptiles and some mammals.  It may act as the insertion point of a persistent part of coracobrachialis. A band of fibrous tissue - ligament of Struthers - joins the tip of the process and medial epicondyle of the humerus.

Compression of median nerve or brachial vessels may occur, but they are usually asymptomatic.