Hourglass-like constriction of the axillary nerve: report of two patients.

Among the various etiologies of compressive lesions, the development of an hourglass-like constriction of the nerve that is unrelated to any recognizably compressive structure is a very rare phenomenon. This problem has been reported previously for the radial nerve and its branch posterior interosseous nerve and for the anterior interosseous nerve, a branch of median nerve. Here we report 2 cases of hourglass-like constriction of the axillary nerve that were observed during surgery; the constrictive segment was unrelated to any compressive structure.