A BONY SUPKACONDYLOID FORAME^t i^ ^AN". 



WITH REMARKS ABOUT SUPRACONDYLOID AND OTHER PROCESSES 

 FROM THE LOWER END OF THE HUMERUS. 



BY 



THOMAS DWIGHT, M. D., LL. D., 



ParJcman Professor of Anatomy at the Harvard Medical School. 



With 1 Plate. 



This foramen (Fig. 1) which, so far as I know, is unique in litera- 

 ture, occurs in the left humerus from the body of a white woman aged 

 57. There is neither supracondyloid foramen nor process on the right 

 one. Otherwise the humeri are very symmetrical, and present no signs 

 of pathological ossifications. The length of each is 28.5 cm. The 

 angle of torsion of the right humerus is 157 degrees, and on the left 

 160 degrees. The process inclosing the foramen springs from the inner 

 surface about midway between the internal and anterior borders 63 mm. 

 above the lowest part of the trochlea. It arises by an extremely thin 

 triangular expansion, about 1 cm. broad from above downwards, and 

 is continued as a slightly convex arch 32 mm. long, measured on the 

 convexity, to end in another triangular expansion some 4 mm. broad on 

 the anterior surface of the internal condyle, 2 cm. above its lower 

 border. The foramen, therefore, is bounded wholly by bone. The pro- 

 cess is an extremely delicate structure, especially in the upper two thirds, 

 where its thickness is that of paper. The lower end is from 1 to 2 mm. 

 thick. The process is twisted in its course, the expansion at its origin 

 facing outward and forward, and that at its end forward and inward. 

 The thinner part above passes into the thicker part below without any 

 change of character. 



The median nerve ran through the foramen. The brachial artery 

 passed over the origin of the process. The brachial artery and its 

 branches were very small; the anterior circumflex was very minute, pos- 

 sibly represented by two twigs, the posterior circumflex was represented 

 by a branch from the superior profunda. At about the usual place of 

 division the brachial gave off a radial artery of about half the diameter 

 of the ulnar, which latter seemed to be the direct continuation. The 



American Journal of Anatomy. — Vol. III. 

 17 



