Joints of the Upper Extremity. 



183 



Humerus 



Ligamentum collaterale radiale 



Membrana interossea antibrachii 



Ligamentum annulare radii Eadius 



Ulna 



Capsula articularis 



234. Right elbow joint, articulatio cubiti, 



from the radial side. 



Articulatio cubiti (continued) (see also Figs. 232, 233, 235237). It possesses as a 

 second strengthening ligament on its radial side the ligamentum collaterale radiale (0."T. 

 external lateral ligament) (see also Fig. 232). This arises as a strong bundle on the epi- 

 condylus lateralis humeri and divides into two diverging fibre bands of which one goes in front 

 of, the other behind the capitulum radii; they are attached to the ulna partly in front of the 

 incisura radialis, partly behind it and to the radial margin of the incisura semilunaris ; distal- 

 ward they reach as far as the level of the collum radii. The space between the diverging 

 limbs of this ligament is filled up by fibres which surround the capitulum and collum radii 

 circularly and which partially unite with the limbs mentioned, partially are fastened separately 

 to the ulna in front and behind the incisura radialis; these circular fibre bands are most 

 markedly developed at the distal part and are grouped together there especially, under the 

 name, ligamentum annulare radii (0. T. orbicular ligament) (see also Fig. 237), but they are 

 only artificially, not sharply, separable from the others. 



